1
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Abbod M, Mohammad A. Combined interaction of fungicides binary mixtures: experimental study and machine learning-driven QSAR modeling. Sci Rep 2024; 14:12700. [PMID: 38830957 DOI: 10.1038/s41598-024-63708-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 05/31/2024] [Indexed: 06/05/2024] Open
Abstract
Fungicide mixtures are an effective strategy in delaying the development of fungicide resistance. In this research, a fixed ratio ray design method was used to generate fifty binary mixtures of five fungicides with diverse modes of action. The interaction of these mixtures was then analyzed using CA and IA models. QSAR modeling was conducted to assess their fungicidal activity through multiple linear regression (MLR), support vector machine (SVM), and artificial neural network (ANN). Most mixtures exhibited additive interaction, with the CA model proving more accurate than the IA model in predicting fungicidal activity. The MLR model showed a good linear correlation between selected theoretical descriptors by the genetic algorithm and fungicidal activity. However, both ML-based models demonstrated better predictive performance than the MLR model. The ANN model showed slightly better predictability than the SVM model, with R2 and R2cv at 0.91 and 0.81, respectively. For external validation, the R2test value was 0.845. In contrast, the SVM model had values of 0.91, 0.78, and 0.77 for the same metrics. In conclusion, the proposed ML-based model can be a valuable tool for developing potent fungicidal mixtures to delay fungicidal resistance emergence.
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Affiliation(s)
- Mohsen Abbod
- Department of Plant Protection, Faculty of Agriculture, Al-Baath University, Homs, Syria.
| | - Ahmad Mohammad
- Department of Plant Protection, Faculty of Agriculture, Al-Baath University, Homs, Syria
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2
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Ballu A, Ugazio C, Duplaix C, Noly A, Wullschleger J, Torriani SFF, Dérédec A, Carpentier F, Walker AS. Preventing multi-resistance: New insights for managing fungal adaptation. Environ Microbiol 2024; 26:e16614. [PMID: 38570900 DOI: 10.1111/1462-2920.16614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 03/08/2024] [Indexed: 04/05/2024]
Abstract
Sustainable crop protection is vital for food security, yet it is under threat due to the adaptation of a diverse and evolving pathogen population. Resistance can be managed by maximising the diversity of selection pressure through dose variation and the spatial and temporal combination of active ingredients. This study explores the interplay between operational drivers for maximising the sustainability of management strategies in relation to the resistance status of fungal populations. We applied an experimental evolution approach to three artificial populations of Zymoseptoria tritici, an economically significant wheat pathogen, each differing in initial resistance status. Our findings reveal that diversified selection pressure curtails the selection of resistance in naïve populations and those with low frequencies of single resistance. Increasing the number of modes of action most effectively delays resistance development, surpassing the increase in the number of fungicides, fungicide choice based on resistance risk, and temporal variation in fungicide exposure. However, this approach favours generalism in the evolved populations. The prior presence of multiple resistant isolates and their subsequent selection in populations override the effects of diversity in management strategies, thereby invalidating any universal ranking. Therefore, the initial resistance composition must be specifically considered in sustainable resistance management to address real-world field situations.
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Affiliation(s)
- Agathe Ballu
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
| | - Claire Ugazio
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
| | | | - Alicia Noly
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
| | | | | | - Anne Dérédec
- Université Paris-Saclay, INRAE, UR BIOGER, Palaiseau, France
| | - Florence Carpentier
- Université Paris-Saclay, INRAE, UR MaIAGE, Jouy-en-Josas, France
- AgroParisTech, Palaiseau Cedex, France
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3
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Helps J, Lopez-Ruiz F, Zerihun A, van den Bosch F. Do Growers Using Solo Fungicides Affect the Durability of Disease Control of Growers Using Mixtures and Alternations? The Case of Spot-Form Net Blotch in Western Australia. PHYTOPATHOLOGY 2024; 114:590-602. [PMID: 38079394 DOI: 10.1094/phyto-02-23-0050-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Growers often use alternations or mixtures of fungicides to slow down the development of resistance to fungicides. However, within a landscape, some growers will implement such resistance management methods, whereas others do not, and may even apply solo components of the resistance management program. We investigated whether growers using solo components of resistant management programs affect the durability of disease control in fields of those who implement fungicide resistance management. We developed a spatially implicit semidiscrete epidemiological model for the development of fungicide resistance. The model simulates the development of epidemics of spot-form net blotch disease, caused by the pathogen Pyrenophora teres f. maculata. The landscape comprises three types of fields, grouped according to their treatment program, with spore dispersal between fields early in the cropping season. In one field type, a fungicide resistance management method is implemented, whereas in the two others, it is not, with one of these field types using a component of the fungicide resistance management program. The output of the model suggests that the use of component fungicides does affect the durability of disease control for growers using resistance management programs. The magnitude of the effect depends on the characteristics of the pathosystem, the degree of inoculum mixing between fields, and the resistance management program being used. Additionally, although increasing the amount of the solo component in the landscape generally decreases the lifespan within which the resistance management program provides effective control, situations exist where the lifespan may be minimized at intermediate levels of the solo component fungicide. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Joe Helps
- Rothamsted Research, Harpenden, AL5 2JQ, U.K
| | - Francisco Lopez-Ruiz
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA 6845, Australia
| | - Ayalsew Zerihun
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA 6845, Australia
| | - Frank van den Bosch
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA 6845, Australia
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4
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Boushell SC, Hu M. Postinfection Application of Fenhexamid at Lower Doses in Conjunction with Captan Slowed Fungicide Resistance Selection in Botrytis cinerea on Detached Grape Berries. PHYTOPATHOLOGY 2024; 114:368-377. [PMID: 37606323 DOI: 10.1094/phyto-04-23-0141-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Fungicide resistance is a limiting factor in sustainable crop production. General resistance management strategies such as rotation and mixtures of fungicides with different modes of action have been proven to be effective in many studies, but guidance on fungicide dose or application timing for resistance management remains unclear or debatable. In this study, Botrytis cinerea and the high-risk fungicide fenhexamid were used to determine the effects of fungicide dose, mixing partner, and application timing on resistance selection across varied frequencies of resistance via detached fruit assays. The results were largely consistent with the recent modeling studies that favored the use of the lowest effective fungicide dose for improved resistance management. In addition, even 10% resistant B. cinerea in the population led to about a 40% reduction of fenhexamid efficacy. Overall, our findings show that application of doses less than the fungicide label dose, mixture with the low-risk fungicide captan, and application postinfection seem to be the most effective management strategies in our controlled experimental settings. This somewhat contradicts the previous assumption that preventative sprays help resistance management.
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Affiliation(s)
- Stephen C Boushell
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742
| | - Mengjun Hu
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742
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5
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Oliver C, Cooper M, Ivey ML, Brannen P, Miles T, Lowder S, Mahaffee W, Moyer MM. Fungicide Use Patterns in Select United States Wine Grape Production Regions. PLANT DISEASE 2024; 108:104-112. [PMID: 37486275 DOI: 10.1094/pdis-04-23-0798-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Wine grape production (Vitis sp.) in the United States requires fungicide inputs for disease control. Currently, there is limited data available on vineyard fungicide use patterns. This information is important in developing tailored recommendations for disease management and fungicide stewardship. In this paper, we summarize the wine grape vineyard fungicide use patterns from four major regions: Napa and Sonoma valleys (California), Willamette Valley (Oregon), Columbia Valley (Washington), and several smaller regions east of the Mississippi River in years 2009 to 2020. We learned that the average in-season total fungicide applications ranged regionally from 5.6 to 8. The most commonly applied Fungicide Resistance Action Committee (FRAC) codes in spray programs were FRAC 3, 13, and M02 across all regions, with some variation to the top four groups in each region. Most applications were made on 14-day intervals; however, shorter intervals (7-day) were favored early season, and longer intervals (21-day) were favored late season. Tank-mixing multiple active ingredients was common east of the Mississippi River during all stages of grape development; this action was typically favored during the bloom period in other regions. In a subset of records that participated in FRAC 11 fungicide resistance testing, the average number of FRAC 11 applications after testing was reduced to either no applications or one application in Napa and Sonoma valleys. This survey provides regionally specific data related to fungicide stewardship practices that could be a focus for future stewardship messaging and fungicide resistance selection training, including total product use (selection events), spray intervals (selection pressure), and tank mixing (selection management).[Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Charlotte Oliver
- Washington State University Irrigated Agriculture Research and Extension Center, Prosser, WA 99350
| | - Monica Cooper
- Cooperative Extension, University of California, Napa, CA 94559
| | | | - Phillip Brannen
- Plant Pathology Department, University of Georgia, Athens, GA 30602
| | - Timothy Miles
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Sarah Lowder
- Agriculture Research Service Horticulture Crops Research Unit, United States Department of Agriculture, Corvallis, OR 97331
| | - Walter Mahaffee
- Agriculture Research Service Horticulture Crops Research Unit, United States Department of Agriculture, Corvallis, OR 97331
| | - Michelle M Moyer
- Washington State University Irrigated Agriculture Research and Extension Center, Prosser, WA 99350
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Pintye A, Németh MZ, Molnár O, Horváth ÁN, Matolcsi F, Bókony V, Spitzmüller Z, Pálfi X, Váczy KZ, Kovács GM. Comprehensive analyses of the occurrence of a fungicide resistance marker and the genetic structure in Erysiphe necator populations. Sci Rep 2023; 13:15172. [PMID: 37704655 PMCID: PMC10499922 DOI: 10.1038/s41598-023-41454-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 08/26/2023] [Indexed: 09/15/2023] Open
Abstract
Genetically distinct groups of Erysiphe necator, the fungus causing grapevine powdery mildew infect grapevine in Europe, yet the processes sustaining stable genetic differences between those groups are less understood. Genotyping of over 2000 field samples from six wine regions in Hungary collected between 2017 and 2019 was conducted to reveal E. necator genotypes and their possible differentiation. The demethylase inhibitor (DMI) fungicide resistance marker A495T was detected in all wine regions, in 16% of the samples. Its occurrence differed significantly among wine regions and grape cultivars, and sampling years, but it did not differ between DMI-treated and untreated fields. Multilocus sequence analyses of field samples and 59 in vitro maintained isolates revealed significant genetic differences among populations from distinct wine regions. We identified 14 E. necator genotypes, of which eight were previously unknown. In contrast to the previous concept of A and B groups, European E. necator populations should be considered genetically more complex. Isolation by geographic distance, growing season, and host variety influence the genetic structuring of E. necator, which should be considered both during diagnoses and when effective treatments are planned.
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Affiliation(s)
- Alexandra Pintye
- Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary
| | - Márk Z Németh
- Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary.
| | - Orsolya Molnár
- Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary
| | - Áron N Horváth
- Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary
| | - Fruzsina Matolcsi
- Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary
- Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Veronika Bókony
- Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary
| | - Zsolt Spitzmüller
- Food and Wine Research Institute, Eszterházy Károly Catholic University, Eger, Hungary
| | - Xénia Pálfi
- Food and Wine Research Institute, Eszterházy Károly Catholic University, Eger, Hungary
| | - Kálmán Z Váczy
- Food and Wine Research Institute, Eszterházy Károly Catholic University, Eger, Hungary
| | - Gábor M Kovács
- Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary
- Department of Plant Anatomy, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
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7
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Kikway I, Keinath AP, Ojiambo PS. Within-Season Shift in Fungicide Sensitivity Profiles of Pseudoperonospora cubensis Populations in Response to Chemical Control. PLANT DISEASE 2023; 107:PDIS09222056RE. [PMID: 36205688 DOI: 10.1094/pdis-09-22-2056-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Cucurbit downy mildew, caused by Pseudoperonospora cubensis, is an important disease affecting cucurbits worldwide. Chemical control is an effective method for disease control but P. cubensis has a high risk for developing resistance to fungicides. Alternating fungicides with different modes of action is recommended to avoid an increase of resistant subpopulations. Thus, this study was conducted to establish shifts in the sensitivity profiles of P. cubensis isolates during the growing season, wherein chlorothalonil was applied in alternation with either cymoxanil, fluopicolide, or propamocarb in field experiments conducted from 2018 to 2020 at Rocky Mount, NC and in 2018 and 2020 at Charleston, SC. The sensitivity of baseline isolates sampled early in the season or exposed isolates sampled late in the season to these single-site fungicides was determined using a detached-leaf assay, where tested isolates were classified as sensitive or resistant based on the relative disease severity. Based on the Kruskal-Wallis test, the distribution profile of relative disease severity among baseline and exposed isolates was significantly different where chlorothalonil was alternated with fluopicolide (χ2 = 10.82; P = 0.001) but not with cymoxanil (χ2 = 1.39; P = 0.238) or propamocarb (χ2 = 2.37; P = 0.412). Although there was a directional selection toward resistance for isolates sampled from plots that were treated with fluopicolide or propamocarb alternated with chlorothalonil during a growing season, a significant shift in fungicide sensitivity distribution based on combined data were observed for fluopicolide (χ2 = 8.25; P = 0.004) but not propamocarb (χ2 = 1.05; P = 0.461). Baseline and exposed isolates sampled from the cymoxanil-treated plots were all resistant to this fungicide and there was no significant shift in their fungicide sensitivity profile during a growing season (χ2 = 0.06; P = 1.000). These results indicate that a shift toward reduced sensitivity in P. cubensis can occur during a growing season and the efficacy of fluopicolide is likely to decrease as the frequency of the less sensitive subpopulations increases during a production season. The resultant effect on disease severity and selection of an insensitive subpopulation may accelerate the development of resistance to propamocarb in the southeastern United States.
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Affiliation(s)
- Isaack Kikway
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Anthony P Keinath
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC 29414
| | - Peter S Ojiambo
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
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8
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Taylor NP, Cunniffe NJ. Coupling machine learning and epidemiological modelling to characterise optimal fungicide doses when fungicide resistance is partial or quantitative. J R Soc Interface 2023; 20:20220685. [PMID: 37073520 PMCID: PMC10113818 DOI: 10.1098/rsif.2022.0685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 03/29/2023] [Indexed: 04/20/2023] Open
Abstract
Increasing fungicide dose tends to lead to better short-term control of plant diseases. However, high doses select more rapidly for fungicide resistant strains, reducing long-term disease control. When resistance is qualitative and complete-i.e. resistant strains are unaffected by the chemical and resistance requires only a single genetic change-using the lowest possible dose ensuring sufficient control is well known as the optimal resistance management strategy. However, partial resistance (where resistant strains are still partially suppressed by the fungicide) and quantitative resistance (where a range of resistant strains are present) remain ill-understood. Here, we use a model of quantitative fungicide resistance (parametrized for the economically important fungal pathogen Zymoseptoria tritici) which handles qualitative partial resistance as a special case. Although low doses are optimal for resistance management, we show that for some model parametrizations the resistance management benefit does not outweigh the improvement in control from increasing doses. This holds for both qualitative partial resistance and quantitative resistance. Via a machine learning approach (a gradient-boosted trees model combined with Shapley values to facilitate interpretability), we interpret the effect of parameters controlling pathogen mutation and characterising the fungicide, in addition to the time scale of interest.
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Affiliation(s)
- Nick P. Taylor
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Nik J. Cunniffe
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
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9
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Ballu A, Despréaux P, Duplaix C, Dérédec A, Carpentier F, Walker AS. Antifungal alternation can be beneficial for durability but at the cost of generalist resistance. Commun Biol 2023; 6:180. [PMID: 36797413 PMCID: PMC9935548 DOI: 10.1038/s42003-023-04550-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 02/03/2023] [Indexed: 02/18/2023] Open
Abstract
The evolution of resistance to pesticides is a major burden in agriculture. Resistance management involves maximizing selection pressure heterogeneity, particularly by combining active ingredients with different modes of action. We tested the hypothesis that alternation may delay the build-up of resistance not only by spreading selection pressure over longer periods, but also by decreasing the rate of evolution of resistance to alternated fungicides, by applying an experimental evolution approach to the economically important crop pathogen Zymoseptoria tritici. Our results show that alternation is either neutral or slows the overall resistance evolution rate, relative to continuous fungicide use, but results in higher levels of generalism in evolved lines. We demonstrate that the nature of the fungicides, and therefore their relative intrinsic risk of resistance may underly this trade-off, more so than the number of fungicides and the rhythm of alternation. This trade-off is also dynamic over the course of resistance evolution. These findings open up new possibilities for tailoring resistance management effectively while optimizing interplay between alternation components.
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Affiliation(s)
- Agathe Ballu
- grid.507621.7Université Paris-Saclay, INRAE, UR BIOGER, 91120 Palaiseau, France
| | - Philomène Despréaux
- grid.507621.7Université Paris-Saclay, INRAE, UR BIOGER, 91120 Palaiseau, France
| | - Clémentine Duplaix
- grid.507621.7Université Paris-Saclay, INRAE, UR BIOGER, 91120 Palaiseau, France
| | - Anne Dérédec
- grid.507621.7Université Paris-Saclay, INRAE, UR BIOGER, 91120 Palaiseau, France
| | - Florence Carpentier
- grid.507621.7Université Paris-Saclay, INRAE, UR MaIAGE, 78350 Jouy-en-Josas, France ,grid.417885.70000 0001 2185 8223AgroParisTech, 91120 Palaiseau, France
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10
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Madgwick PG, Kanitz R. Beyond redundant kill: A fundamental explanation of how insecticide mixtures work for resistance management. PEST MANAGEMENT SCIENCE 2023; 79:495-506. [PMID: 36098048 PMCID: PMC10092901 DOI: 10.1002/ps.7180] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 08/25/2022] [Accepted: 09/13/2022] [Indexed: 05/17/2023]
Abstract
The use of insecticide mixtures for resistance management has been a controversial topic for many decades. Here, we provide a reassessment of the fundamental theory of insecticide mixtures. First, we examine how mixtures differ from other strategies. We suggest that the fundamental strategy concept of a mixture is defined by the simultaneous use of insecticides and their overlapping exposure. Second, we provide a simple, illustrative model to show how mixtures affect resistance evolution. Following the existing literature, we identify a role for 'redundant kill' acting against resistant individuals, which we link to the overlapping exposure of insecticides. We also identify the occurrence of 'additional kill' acting against susceptible individuals, which is the immediate consequence of the simultaneous use of insecticides. Third, we take a basic approach to the comparison of mixtures and other strategies using a simple model. We find that a common comparison of the time to resistance alone leaves the effects of additional kill unaccounted for. Moreover, we demonstrate that different approaches to comparison can lead to different results because of biases that are introduced in the comparison setup. Fourth, still using the same model, we showcase a more sophisticated approach to comparison using optimised strategies. We find that optimised mixtures always perform better than other strategies due to the combination of redundant and additional kill. We suggest that the comparison of optimised strategies is unbiased because each strategy is performing the best that it can. On this basis, in theory (but not necessarily practice), we believe that mixtures are better than other strategies and, through the steps of our argument, we can tie this success back to the fundamental properties (of simultaneous use and overlapping exposure) that distinguish mixtures from other strategy concepts. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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11
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Combined Application of Tacrolimus with Cyproconazole, Hymexazol and Novel {2-(3-R-1 H-1,2,4-triazol-5-yl)phenyl}amines as Antifungals: In Vitro Growth Inhibition and In Silico Molecular Docking Analysis to Fungal Chitin Deacetylase. J Fungi (Basel) 2023; 9:jof9010079. [PMID: 36675900 PMCID: PMC9866229 DOI: 10.3390/jof9010079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/01/2023] [Accepted: 01/03/2023] [Indexed: 01/06/2023] Open
Abstract
Agents with antifungal activity play a vital role as therapeutics in health care, as do fungicides in agriculture. Effectiveness, toxicological profile, and eco-friendliness are among the properties used to select suitable substances. Furthermore, a steady supply of new agents with different modes of action is required to counter the well-known potential of human and phyto-pathogenic fungi to develop resistance against established antifungals. Here, we use an in vitro growth assay to investigate the activity of the calcineurin inhibitor tacrolimus in combination with the commercial fungicides cyproconazole and hymexazol, as well as with two earlier reported novel {2-(3-R-1H-1,2,4-triazol-5-yl)phenyl}amines, against the fungi Aspergillus niger, Colletotrichum higginsianum, Fusarium oxysporum and the oomycete Phytophthora infestans, which are notoriously harmful in agriculture. When tacrolimus was added in a concentration range from 0.25 to 25 mg/L to the tested antifungals (at a fixed concentration of 25 or 50 mg/L), the inhibitory activities were distinctly enhanced. Molecular docking calculations revealed triazole derivative 5, (2-(3-adamantan-1-yl)-1H-1,2,4-triazol-5-yl)-4-chloroaniline), as a potent inhibitor of chitin deacetylases (CDA) of Aspergillus nidulans and A. niger (AnCDA and AngCDA, respectively), which was stronger than the previously reported polyoxorin D, J075-4187, and chitotriose. The results are discussed in the context of potential synergism and molecular mode of action.
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12
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Taylor NP, Cunniffe NJ. Optimal Resistance Management for Mixtures of High-Risk Fungicides: Robustness to the Initial Frequency of Resistance and Pathogen Sexual Reproduction. PHYTOPATHOLOGY 2023; 113:55-69. [PMID: 35881866 DOI: 10.1094/phyto-02-22-0050-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
There is a strong consensus that selection for fungicide resistant pathogen strains can be most effectively limited by using applications of mixtures of fungicides designed to balance disease control against selection. However, how to do this in practice is not entirely characterized. Previous work indicates optimal mixtures of pairs of fungicides which are both at a high risk of resistance can be constructed using pairs of doses that select equally for both single resistant strains in the first year of application. What has not been addressed thus far is the important real-world case in which the initial levels of resistance to each fungicide differ, for example because the chemicals have been available for different lengths of time. We show how recommendations based on equal selection in the first year can be suboptimal in this case. We introduce a simple alternative approach, based on equalizing the frequencies of single resistant strains in the year that achieving acceptable levels of control is predicted to become impossible. We show that this strategy is robust to changes in parameters controlling pathogen epidemiology and fungicide efficacy. We develop our recommendation using a preexisting, parameterized model of Zymoseptoria tritici (the pathogen causing Septoria leaf blotch on wheat), which exemplifies the range of plant pathogens that predominantly spread clonally, but for which sexual reproduction forms an important component of the life cycle. We show that pathogen sexual reproduction can influence the rate at which fungicide resistance develops but does not qualitatively affect our optimal resistance management recommendation. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Nick P Taylor
- Department of Plant Sciences, University of Cambridge, Cambridge, U.K
| | - Nik J Cunniffe
- Department of Plant Sciences, University of Cambridge, Cambridge, U.K
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13
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Mahaffee WF, Margairaz F, Ulmer L, Bailey BN, Stoll R. Catching Spores: Linking Epidemiology, Pathogen Biology, and Physics to Ground-Based Airborne Inoculum Monitoring. PLANT DISEASE 2023; 107:13-33. [PMID: 35679849 DOI: 10.1094/pdis-11-21-2570-fe] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Monitoring airborne inoculum is gaining interest as a potential means of giving growers an earlier warning of disease risk in a management unit or region. This information is sought by growers to aid in adapting to changes in the management tools at their disposal and the market-driven need to reduce the use of fungicides and cost of production. To effectively use inoculum monitoring as a decision aid, there is an increasing need to understand the physics of particle transport in managed and natural plant canopies to effectively deploy and use near-ground aerial inoculum data. This understanding, combined with the nuances of pathogen-specific biology and disease epidemiology, can serve as a guide to designing improved monitoring approaches. The complexity of any pathosystem and local environment are such that there is not a generalized approach to near-ground air sampler placement, but there is a conceptual framework to arrive at a "semi-optimal" solution based on available resources. This review is intended as a brief synopsis of the linkages among pathogen biology, disease epidemiology, and the physics of the aerial dispersion of pathogen inoculum and what to consider when deciding where to locate ground-based air samplers. We leverage prior work in developing airborne monitoring tools for hops, grapes, spinach, and turf, and research into the fluid mechanics governing particle transport in sparse canopies and urban and forest environments. We present simulation studies to demonstrate how particles move in the complex environments of agricultural fields and to illustrate the limited sampling area of common air samplers.
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Affiliation(s)
- Walter F Mahaffee
- United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Corvallis, OR 97330
| | - Fabien Margairaz
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112
| | - Lucas Ulmer
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112
| | - Brian N Bailey
- Department of Plant Sciences, University of California, Davis, Davis, CA 95616
| | - Rob Stoll
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112
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14
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Li X, Wang Q, Li H, Wang X, Zhang R, Yang X, Jiang Q, Shi Q. Revealing the Mechanisms for Linalool Antifungal Activity against Fusarium oxysporum and Its Efficient Control of Fusarium Wilt in Tomato Plants. Int J Mol Sci 2022; 24:ijms24010458. [PMID: 36613902 PMCID: PMC9820380 DOI: 10.3390/ijms24010458] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/29/2022] Open
Abstract
Fusarium oxysporum f. sp. radicis-lycopersici (Forl) is a destructive soil-borne phytopathogenic fungus that causes Fusarium crown and root rot (FCRR) of tomato, leading to considerable field yield losses. In this study, we explored the antifungal capability of linalool, a natural plant volatile organic component, against Forl and its role in controlling FCRR symptoms in tomatoes. Our results showed that Forl mycelial growth was inhibited by the linalool treatment and that the linalool treatment damaged cell membrane integrity, enhanced reactive oxygen species levels, depleted glutathione, and reduced the activities of many antioxidant enzymes in Forl. Transcriptomic and proteomic analyses demonstrated that linalool also downregulated metabolic biosynthetic pathways at the transcript and protein levels, including redox, transporter activity, and carbohydrate metabolism in Forl. Moreover, linalool significantly decreased the expression of many Forl pathogenic genes, such as cell wall degrading enzymes (CWDEs) and G proteins, which is likely how a Forl infection was prevented. Importantly, exogenously applied linalool activated the salicylic acid (SA) and jasmonic acid (JA) defensive pathways to improve disease resistance and relieved the negative effects of Forl on plant growth. Taken together, we report that linalool is an effective fungicide against Forl and will be a promising green chemical agent for controlling FCRR.
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15
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Jørgensen LN, Matzen N, Heick TM, O’Driscoll A, Clark B, Waite K, Blake J, Glazek M, Maumene C, Couleaud G, Rodemann B, Weigand S, Bataille C, R B, Hellin P, Kildea S, Stammler G. Shifting sensitivity of septoria tritici blotch compromises field performance and yield of main fungicides in Europe. FRONTIERS IN PLANT SCIENCE 2022; 13:1060428. [PMID: 36483948 PMCID: PMC9723467 DOI: 10.3389/fpls.2022.1060428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/26/2022] [Indexed: 06/17/2023]
Abstract
Septoria tritici blotch (STB; Zymoseptoria tritici) is a severe leaf disease on wheat in Northern Europe. Fungicide resistance in the populations of Z. tritici is increasingly challenging future control options. Twenty-five field trials were carried out in nine countries across Europe from 2019 to 2021 to investigate the efficacy of specific DMI and SDHI fungicides against STB. During the test period, two single DMIs (prothioconazole and mefentrifluconazole) and four different SDHIs (fluxapyroxad, bixafen, benzovindiflupyr and fluopyram) along with different co-formulations of DMIs and SDHIs applied at flag leaf emergence were tested. Across all countries, significant differences in azole performances against STB were seen; prothioconazole was outperformed in all countries by mefentrifluconazole. The effects also varied substantially between the SDHIs, with fluxapyroxad providing the best efficacy overall, while the performance of fluopyram was inferior to other SDHIs. In Ireland and the UK, the efficacy of SDHIs was significantly lower compared with results from continental Europe. This reduction in performances from both DMIs and SDHIs was reflected in yield responses and also linked to decreased sensitivity of Z. tritici isolates measured as EC50 values. A clear and significant gradient in EC50 values was seen across Europe. The lower sensitivity to SDHIs in Ireland and the UK was coincident with the prevalence of SDH-C-alterations T79N, N86S, and sporadically of H152R. The isolates' sensitivity to SDHIs showed a clear cross-resistance between fluxapyroxad, bixafen, benzovindiflupyr and fluopyram, although the links with the latter were less apparent. Co-formulations of DMIs + SDHIs performed well in all trials conducted in 2021. Only minor differences were seen between fluxapyroxad + mefentrifluconazole and bixafen + fluopyram + prothioconazole; the combination of benzovindiflupyr + prothioconazole gave an inferior performance at some sites. Fenpicoxamid performed in line with the most effective co-formulations. This investigation shows a clear link between reduced field efficacy by solo SDHIs as a result of increasing problems with sensitivity shifting and the selection of several SDH-C mutations. The presented data stress the need to practice anti-resistance strategies to delay further erosion of fungicide efficacy.
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Affiliation(s)
| | - Niels Matzen
- Department of Agroecology, Aarhus University, Slagelse, Denmark
| | | | | | | | | | | | | | - Claude Maumene
- Arvalis Institut du végétal, Station Expérimentale, Boigneville, France
| | - Gilles Couleaud
- Arvalis Institut du végétal, Station Expérimentale, Boigneville, France
| | | | - Stephan Weigand
- Institut für Pflanzenschutz, Bayerische Landesanstalt für Landwirtschaft, Freising-Weihenstephan, Germany
| | | | - Bán R
- Institute of Plant Protection, Department of Integrated Plant Protection, Hungarian University of Agriculture and Life Sciences (MATE), Gödöllő, Hungary
| | - Pierre Hellin
- CRA-W, Plant and Forest Health Unit, Gembloux, Belgium
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16
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Toporek SM, Keinath AP. Efficacy of Fungicides Used to Manage Downy Mildew in Cucumber Assessed with Multiple Meta-Analysis Techniques. PHYTOPATHOLOGY 2022; 112:1651-1658. [PMID: 35263164 DOI: 10.1094/phyto-10-21-0432-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A nationwide, quantitative synthesis of fungicide efficacy data on management of cucurbit downy mildew (CDM) caused by Pseudoperonospora cubensis is needed to broadly evaluate fungicide performance. Three-level meta-analysis, three-level meta-regression, and network meta-analyses were conducted on data from 46 cucumber (Cucumis sativus) CDM fungicide efficacy studies conducted in the eastern United States retrieved from Plant Disease Management Reports published between 2009 and 2018. Three response variables were examined in each analysis: disease severity, marketable yield, and total yield, from which percent disease control and percent yield return compared with nontreated controls was calculated. Moderator variables used in the three-level meta-analysis or three-level meta-regression included year, disease pressure, number of fungicide applications, and slicing or pickling cucumbers. In the network meta-analysis, fungicides were grouped by common combinations of Fungicide Resistance Action Committee Codes and modes of action. Overall, fungicides significantly (P < 0.001) reduced disease severity and increased marketable and total yields, resulting in a mean 54.0% disease control and 61.9% marketable and 73.3% total yield return. Subgroup differences were observed for several fungicide applications, control plot disease severity, and cucumber type for marketable yield. Based on the meta-regression analysis for disease severity by year, fungicide efficacy has been decreasing from 2009 to 2018, potentially indicating broad development of fungicide resistance over time. Treatments containing quinone inside inhibitors, pyridinylmethyl-benzamides, and protectants and treatments containing oxysterol binding protein inhibitors and protectants most effectively reduced disease severity. The most effective fungicide combinations for disease control did not always result in the highest yield return.
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Affiliation(s)
- Sean M Toporek
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC 29414
| | - Anthony P Keinath
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC 29414
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17
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Kikway I, Keinath AP, Ojiambo PS. Temporal Dynamics and Severity of Cucurbit Downy Mildew Epidemics as Affected by Chemical Control and Cucurbit Host Type. PLANT DISEASE 2022; 106:1009-1019. [PMID: 34735276 DOI: 10.1094/pdis-09-21-1992-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Cucurbit downy mildew caused by the oomycete Pseudoperonospora cubensis is an important disease that affects members of Cucurbitaceae family globally. However, temporal dynamics of the disease have not been characterized at the field scale to understand how control strategies influence disease epidemics. Disease severity was assessed visually on cucumber and summer squash treated with weekly alternation of chlorothalonil with cymoxanil, fluopicolide, or propamocarb during the 2018 spring season and 2019 and 2020 fall seasons in North Carolina and the 2018 and 2020 fall seasons in South Carolina. Disease onset was observed around mid-June during the spring season and early September during the fall season, followed by a rapid increase in severity until mid-July in the spring season and late September or mid-October in the fall season, typical of polycyclic epidemics. The Gompertz, logistic, and monomolecular growth models were fitted to disease severity using linear regression and parameter estimates to compare the effects of fungicide treatment and cucurbit host type on disease progress. The Gompertz and logistic models were more appropriate than the monomolecular model in describing temporal dynamics of cucurbit downy mildew, with the Gompertz model providing the best description for 34 of the 44 epidemics examined. Fungicide treatment and host type significantly (P < 0.0001) affected the standardized area under disease progress curve (sAUDPC), final disease severity (Final DS), and weighted mean absolute rates of disease progress (ρ), with these variables, in most cases, being significantly (P < 0.05) lower in fungicide-treated plots than in untreated control plots. Except in a few cases, sAUDPC, Final DS, and ρ were lower in cases where chlorothalonil was alternated with fluopicolide or propamocarb than in cases where chlorothalonil was alternated with cymoxanil or when chlorothalonil was applied alone. These results characterized the temporal progress of cucurbit downy mildew and provided an improved understanding of the dynamics of the disease at the field level. Parameters of disease progress obtained from this study could serve as inputs in simulation studies to assess the efficacy of fungicide alternation in managing fungicide resistance in this pathosystem.
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Affiliation(s)
- Isaack Kikway
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Anthony P Keinath
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC 29414
| | - Peter S Ojiambo
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
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18
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Oliver CL, Moyer M. Influence of sustainability programs on fungicide stewardship practices in Pacific Northwest United States vineyards. BIO WEB OF CONFERENCES 2022. [DOI: 10.1051/bioconf/20225003012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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19
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Anand G, Rajeshkumar KC. Challenges and Threats Posed by Plant Pathogenic Fungi on Agricultural Productivity and Economy. Fungal Biol 2022. [DOI: 10.1007/978-981-16-8877-5_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Abstract
Plant disease threatens the environmental and financial sustainability of crop production, causing $220 billion in annual losses. The dire threat disease poses to modern agriculture demands tools for better detection and monitoring to prevent crop loss and input waste. The nascent discipline of plant disease sensing, or the science of using proximal and/or remote sensing to detect and diagnose disease, offers great promise to extend monitoring to previously unachievable resolutions, a basis to construct multiscale surveillance networks for early warning, alert, and response at low latency, an opportunity to mitigate loss while optimizing protection, and a dynamic new dimension to agricultural systems biology. Despite its revolutionary potential, plant disease sensing remains an underdeveloped discipline, with challenges facing both fundamental study and field application. This article offers a perspective on the current state and future of plant disease sensing, highlights remaining gaps to be filled, and presents a bold vision for the future of global agriculture.
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21
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Hellin P, Duvivier M, Heick TM, Fraaije BA, Bataille C, Clinckemaillie A, Legrève A, Jørgensen LN, Andersson B, Samils B, Rodemann B, Berg G, Hutton F, Garnault M, El Jarroudi M, Couleaud G, Kildea S. Spatio-temporal distribution of DMI and SDHI fungicide resistance of Zymoseptoria tritici throughout Europe based on frequencies of key target-site alterations. PEST MANAGEMENT SCIENCE 2021; 77:5576-5588. [PMID: 34392616 DOI: 10.1002/ps.6601] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 08/15/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Over the past decade, demethylation inhibitor (DMI) and succinate dehydrogenase inhibitor (SDHI) fungicides have been extensively used to control to septoria tritici blotch, caused by Zymoseptoria tritici on wheat. This has led to the development and selection of alterations in the target-site enzymes (CYP51 and SDH, respectively). RESULTS Taking advantage of newly and previously developed qPCR assays, the frequency of key alterations associated with DMI (CYP51-S524T) and SDHI (SDHC-T79N/I, C-N86S and C-H152R) resistance was assessed in Z. tritici-infected wheat leaf samples collected from commercial crops (n = 140) across 14 European countries prior to fungicide application in the spring of 2019. This revealed the presence of a West to East gradient in the frequencies of the most common key alterations conferring azole (S524T) and SDHI resistance (T79N and N86S), with the highest frequencies measured in Ireland and Great Britain. These observations were corroborated by sequencing (CYP51 and SDH subunits) and sensitivity phenotyping (prothioconazole-desthio and fluxapyroxad) of Z. tritici isolates collected from a selection of field samples. Additional sampling made at the end of the 2019 season confirmed the continued increase in frequency of the targeted alterations. Investigations on historical leaf DNA samples originating from different European countries revealed that the frequency of all key alterations (except C-T79I) has been gradually increasing over the past decade. CONCLUSION Whilst these alterations are quickly becoming dominant in Ireland and Great Britain, scope still exists to delay their selection throughout the wider European population, emphasizing the need for the implementation of fungicide antiresistance measures. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Pierre Hellin
- Plant and Forest Health Unit, Walloon Agricultural Research Center, Gembloux, Belgium
| | - Maxime Duvivier
- Plant and Forest Health Unit, Walloon Agricultural Research Center, Gembloux, Belgium
| | - Thies M Heick
- Department of Agroecology, Aarhus University, Slagelse, Denmark
| | | | - Charlotte Bataille
- Plant and Forest Health Unit, Walloon Agricultural Research Center, Gembloux, Belgium
| | | | - Anne Legrève
- Applied Microbiology, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | | | - Björn Andersson
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Berit Samils
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Bernd Rodemann
- Department of Mycology and Virology, Julius Kühn-Institut, Braunschweig, Germany
| | - Gunilla Berg
- Plant Protection Centre, Swedish Board of Agriculture, Alnarp, Sweden
| | - Fiona Hutton
- Teagasc, The Agriculture and Food Development Authority, Carlow, Ireland
| | - Maxime Garnault
- AgroParisTech, UMR BIOGER, INRAE, Université Paris-Saclay, Thiverval-Grignon, France
| | - Moussa El Jarroudi
- Department of Environmental Sciences and Management, University of Liège, Arlon Campus Environnement, Arlon, Belgium
| | | | - Steven Kildea
- Teagasc, The Agriculture and Food Development Authority, Carlow, Ireland
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22
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Jeong JY, Kim B, Ji SY, Baek YC, Kim M, Park SH, Kim KH, Oh SI, Kim E, Jung H. Effect of Pesticide Residue in Muscle and Fat Tissue of Pigs Treated with Propiconazole. Food Sci Anim Resour 2021; 41:1022-1035. [PMID: 34796328 PMCID: PMC8564320 DOI: 10.5851/kosfa.2021.e53] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/06/2021] [Accepted: 09/09/2021] [Indexed: 01/15/2023] Open
Abstract
This study estimated the effect of exposure to propiconazole through
implementation and residues in finishing pigs. We analyzed the expression of
fibrosis-related genes and performed histological analysis of the blood, liver,
kidney, muscle, ileum, and fat tissues. The animals were exposed for 28 d to
different concentrations of propiconazole (0.09, 0.44, 0.88, 4.41, and 8.82
mg/kg bw/d). Quantitative, gene expression, and histological analyses in tissues
were performed using liquid chromatography mass spectrometry, real-time PCR, and
Masson’s trichrome staining, respectively. Final body weight did not
differ among groups. However, genes involved in fibrosis were significantly
differentially regulated in response to propiconazole concentrations. Glucose,
alanine aminotransferase, and total bilirubin levels were significantly
increased compared with those in the control group, while alkaline phosphatase
level was decreased (p<0.05) after exposure to propiconazole. The residue
limits of propiconazole were increased in the finishing phase at 4.41 and 8.82
mg/kg bw/d. The liver, kidney, and ileum showed blue staining after
propiconazole treatment, confirmed by Masson's trichrome staining. In
conclusion, these findings suggest that propiconazole exposure disturbs the
expression of fibrosis-related genes. This study on dietary propiconazole in
pigs can provide a basis for determining maximum residue limits and a better
understanding of metabolism in pigs and meat products.
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Affiliation(s)
- Jin Young Jeong
- Animal Nutrition & Physiology Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Byeonghyeon Kim
- Animal Nutrition & Physiology Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Sang Yun Ji
- Animal Nutrition & Physiology Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Youl Chang Baek
- Animal Nutrition & Physiology Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Minji Kim
- Animal Nutrition & Physiology Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Seol Hwa Park
- Animal Nutrition & Physiology Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Ki Hyun Kim
- Animal Welfare Research Team, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Sang-Ik Oh
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Eunju Kim
- Division of Animal Disease & Health, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
| | - Hyunjung Jung
- Animal Nutrition & Physiology Division, National Institute of Animal Science, Rural Development Administration, Wanju 55365, Korea
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23
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Are Efficient-Dose Mixtures a Solution to Reduce Fungicide Load and Delay Evolution of Resistance? An Experimental Evolutionary Approach. Microorganisms 2021; 9:microorganisms9112324. [PMID: 34835451 PMCID: PMC8622124 DOI: 10.3390/microorganisms9112324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/28/2021] [Accepted: 10/31/2021] [Indexed: 11/17/2022] Open
Abstract
Pesticide resistance poses a critical threat to agriculture, human health and biodiversity. Mixtures of fungicides are recommended and widely used in resistance management strategies. However, the components of the efficiency of such mixtures remain unclear. We performed an experimental evolutionary study on the fungal pathogen Z. tritici to determine how mixtures managed resistance. We compared the effect of the continuous use of single active ingredients to that of mixtures, at the minimal dose providing full control of the disease, which we refer to as the "efficient" dose. We found that the performance of efficient-dose mixtures against an initially susceptible population depended strongly on the components of the mixture. Such mixtures were either as durable as the best mixture component used alone, or worse than all components used alone. Moreover, efficient dose mixture regimes probably select for generalist resistance profiles as a result of the combination of selection pressures exerted by the various components and their lower doses. Our results indicate that mixtures should not be considered a universal strategy. Experimental evaluations of specificities for the pathogens targeted, their interactions with fungicides and the interactions between fungicides are crucial for the design of sustainable resistance management strategies.
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24
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Jørgensen LN, Heick TM. Azole Use in Agriculture, Horticulture, and Wood Preservation - Is It Indispensable? Front Cell Infect Microbiol 2021; 11:730297. [PMID: 34557427 PMCID: PMC8453013 DOI: 10.3389/fcimb.2021.730297] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 08/11/2021] [Indexed: 11/25/2022] Open
Abstract
Plant pathogens cause significant damage to plant products, compromising both quantities and quality. Even though many elements of agricultural practices are an integral part of reducing disease attacks, modern agriculture is still highly reliant on fungicides to guarantee high yields and product quality. The azoles, 14-alpha demethylase inhibitors, have been the fungicide class used most widely to control fungal plant diseases for more than four decades. More than 25 different azoles have been developed for the control of plant diseases in crops and the group has a world market value share of 20-25%. Azoles have proven to provide long-lasting control of many target plant pathogens and are categorized to have moderate risk for developing fungicide resistance. Field performances against many fungal pathogens have correspondingly been stable or only moderately reduced over time. Hence azoles are still, to date, considered the backbone in many control strategies and widely used as solo fungicides or as mixing partners with other fungicide groups, broadening the control spectrum as well as minimizing the overall risk of resistance development. This review describes the historic perspective of azoles, their market shares and importance for production of major crops like cereals, rice, oilseed rape, sugar beet, banana, citrus, and soybeans. In addition, information regarding use in amenity grass, in the wood preservation industry and as plant growth regulators are described. At the end of the review azoles are discussed in a wider context including future threats following stricter requirements for registration and potential impact on human health.
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Beckie HJ, Busi R, Lopez-Ruiz FJ, Umina PA. Herbicide resistance management strategies: how do they compare with those for insecticides, fungicides and antibiotics? PEST MANAGEMENT SCIENCE 2021; 77:3049-3056. [PMID: 33821561 DOI: 10.1002/ps.6395] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/22/2021] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
Herbicides are the largest category of pesticides used in global agriculture, which is reflected in the rate of increase in the number of unique cases of herbicide-resistant weed biotypes since the late 1950s. Recommended herbicide resistance management strategies and tactics have evolved over the past 50 years through cumulative research and experience and have been regularly reviewed. Nevertheless, new perspectives may be gained by viewing current recommended strategies through the lens of insecticide, fungicide, and antibiotic resistance management. What commonalities exist and what is the basis for disparate strategies? Although pesticide and antibiotic mixtures (or combinations) are generally more effective than rotations (or alternations) in mitigating or managing resistance, the latter strategy is often employed because of greater ease of implementation and other reasons. We conclude that there are more common than different strategies for mitigating or managing pesticide and antibiotic resistance. Overall, a reduction in selection pressure for resistance evolution through diverse multi-tactic management programmes, and disruption or mitigation of the dispersal or transmission of problematic genotypes are needed to sustain the longevity of current and future mode-of-action products for crop and human health protection. © 2021 Society of Chemical Industry. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Hugh J Beckie
- Australian Herbicide Resistance Initiative, School of Agriculture and Environment, The University of Western Australia, Perth, Australia
| | - Roberto Busi
- Australian Herbicide Resistance Initiative, School of Agriculture and Environment, The University of Western Australia, Perth, Australia
| | - Francisco J Lopez-Ruiz
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, Australia
| | - Paul A Umina
- School of BioSciences, The University of Melbourne, Melbourne, Australia
- Cesar Australia, Parkville, Australia
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Cook NM, Chng S, Woodman TL, Warren R, Oliver RP, Saunders DG. High frequency of fungicide resistance-associated mutations in the wheat yellow rust pathogen Puccinia striiformis f. sp. tritici. PEST MANAGEMENT SCIENCE 2021; 77:3358-3371. [PMID: 33786966 DOI: 10.1002/ps.6380] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/23/2021] [Accepted: 03/31/2021] [Indexed: 05/14/2023]
Abstract
BACKGROUND Reliance on fungicides to manage disease creates selection pressure for the evolution of resistance in fungal and oomycete pathogens. Rust fungi (Pucciniales) are major pathogens of cereals and other crops and have been classified as low-risk for developing resistance to fungicides; no case of field failure of fungicides in a cereal rust disease has yet been recorded. Recently, the Asian soybean rust pathogen, Phakopsora pachyrhizi evolved resistance to several fungicide classes, prompting us to screen a large sample of the globally widespread wheat yellow rust pathogen, Puccinia striiformis f. sp. tritici (Pst), for mutations associated with fungicide resistance. RESULTS We evaluated 363 Pst isolates from Europe, the USA, Ethiopia, Chile, China and New Zealand for mutations in the target genes of demethylase inhibitor (DMI; Cyp51) and succinate dehydrogenase inhibitor (SDHI; SdhB, SdhC and SdhD) fungicides. A high proportion of Pst isolates carrying a Y134F DMI resistance-associated substitution in the Cyp51 gene was found among those from China and New Zealand. A set of geographically diverse Pst isolates was also found to display a substitution in SdhC (I85V) that is homologous to that reported recently in P. pachyrhizi and linked to SDHI resistance. CONCLUSION The identification of resistance-associated alleles confirms that cereal rusts are not immune to fungicide resistance and that selection for resistance evolution is operating at high levels in certain locations. It highlights the need to adopt fungicide resistance management practices and to monitor cereal rust species for development of resistance. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Nicola M Cook
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - Soonie Chng
- The New Zealand Institute for Plant & Food Research Limited, Lincoln, New Zealand
| | | | - Rachael Warren
- The New Zealand Institute for Plant & Food Research Limited, Lincoln, New Zealand
| | - Richard P Oliver
- Molecular and Life Sciences, Curtin University, Bentley, Australia
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Monitoring systems for resistance to plant protection products across the world: Between redundancy and complementarity. PEST MANAGEMENT SCIENCE 2021; 77:2697-2709. [PMID: 33433052 DOI: 10.1002/ps.6275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 12/19/2020] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Monitoring resistance to plant protection products (PPPs) is crucial for understanding the evolution of resistances in bioagressors, thereby allowing scientists to design sound bioagressor management strategies. Globally, resistance monitoring is implemented by a wide range of actors that fall into three distinct categories: academic, governmental, and private. The purpose of this study was to investigate worldwide diversity in PPP resistance monitoring systems and to shed light on their different facets. RESULTS A large survey involving 162 experts from 48 countries made it possible to identify and analyze 250 resistance monitoring systems. Through an in-depth analysis, the features of the different monitoring systems were identified. The main factor differentiating monitoring systems was essentially the capabilities (funding, manpower, technology, etc.) of the actors involved in each system. In most countries, and especially in those with a high Human Development Index, academic, governmental, and private monitoring systems coexist. Overall, systems focus far more on monitoring established resistances than on the detection of emerging resistances. Governmental and private resistance monitoring systems generally have considerable capacities to generate data, whereas academic resistance monitoring systems are more specialized. Governmental actors federate and enroll a wider variety of stakeholders. CONCLUSION The results show functional complementarities between the coexisting actors in countries where they coexist. We suggest PPP resistance monitoring might be enhanced if the different actors focus more on detecting emerging resistances (and associated benefits) and increase collaborative and collective efforts and transparency. © 2021 Society of Chemical Industry.
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Guo Y, Chen J, Ren D, Du B, Wu L, Zhang Y, Wang Z, Qian S. Synthesis of osthol-based botanical fungicides and their antifungal application in crop protection. Bioorg Med Chem 2021; 40:116184. [PMID: 33971489 DOI: 10.1016/j.bmc.2021.116184] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 02/07/2023]
Abstract
Plant pathogenic fungi decrease the quality and productivity of plant production. The botanical fungicides have better biocompatibility and rapid biodegradation, little or no cross resistance, and the structural diversity, and thus are beneficial to deal with plant fungal diseases. Osthole has been widely used as the commercial botanical fungicide against powdery mildew in China. In this article, a series of osthole derivatives were synthesized, which respectively contain different substituents on the benzene ring, at the C8-position and pyrone ring. All the target compounds were evaluated in vitro for their antifungal activity against resistant phytopathogenic fungi. Colletotrichum fragariae, Strawberry Botrytis Cinerea, Kiwifruit Botrytis Cinerea, Kiwifruit brown Rots, which are common in fruit fungal diseases. The compound C4 was identified as the most promising candidate with the EC50 values at 38.7 µg/mL against Colletotrichum Fragariae, 14.5 µg/mL against Strawberry Botrytis Cinerea and 24.3 µg/mL against Kiwifruit Botrytis Cinerea, respectively, whereas the antifungal activity against resistant phytopathogenic fungi. of osthole is too low to be used (EC50 > 400 ppm). The results of mycelial relative conductivity determination, PI uptake and fluorescence spectroscopy indicated that the cell membrane of fungi is the key action site of C4. Besides, C4 has the potent inhibitory activity against both of plant and human pathogenic bacteria. Our studies showed that C4 was worthy for further attention as a promising botanical fungicide candidate in crop protection.
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Affiliation(s)
- Yuying Guo
- Department of Pharmaceutical Engineering, College of Food and Bioengineering, Xihua University, Chengdu 610039, China
| | - Jiabao Chen
- Department of Pharmaceutical Engineering, College of Food and Bioengineering, Xihua University, Chengdu 610039, China
| | - Dan Ren
- Chengdu New Sun Crop Science CO., LTD., Chengdu 610041, China
| | - Bo Du
- Chengdu New Sun Crop Science CO., LTD., Chengdu 610041, China
| | - Lei Wu
- Department of Pharmaceutical Engineering, College of Food and Bioengineering, Xihua University, Chengdu 610039, China
| | - Yuanyuan Zhang
- Department of Chemistry, College of Science, Xihua University, Chengdu 610039, China
| | - Zhouyu Wang
- Department of Chemistry, College of Science, Xihua University, Chengdu 610039, China.
| | - Shan Qian
- Department of Pharmaceutical Engineering, College of Food and Bioengineering, Xihua University, Chengdu 610039, China.
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Garnault M, Duplaix C, Leroux P, Couleaud G, David O, Walker AS, Carpentier F. Large-scale study validates that regional fungicide applications are major determinants of resistance evolution in the wheat pathogen Zymoseptoria tritici in France. THE NEW PHYTOLOGIST 2021; 229:3508-3521. [PMID: 33226662 DOI: 10.1111/nph.17107] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 11/16/2020] [Indexed: 06/11/2023]
Abstract
In modern cropping systems, the near-universal use of plant protection products selects for resistance in pest populations. The emergence and evolution of this adaptive trait threaten treatment efficacy. We identified determinants of fungicide resistance evolution and quantified their effects at a large spatiotemporal scale. We focused on Zymoseptoria tritici, which causes leaf blotch in wheat. Phenotypes of qualitative or quantitative resistance to various fungicides were monitored annually, from 2004 to 2017, at about 70 sites throughout 22 regions of France (territorial units of 25 000 km2 on average). We modelled changes in resistance frequency with regional anti-Septoria fungicide use, yield losses due to the disease and the regional area under organic wheat. The major driver of resistance dynamics was fungicide use at the regional scale. We estimated its effect on the increase in resistance and relative apparent fitness of each resistance phenotype. The predictions of the model replicated the spatiotemporal patterns of resistance observed in field populations (R2 from 0.56 to 0.82). The evolution of fungicide resistance is mainly determined at the regional scale. This study therefore showed that collective management at the regional scale could effectively complete local actions.
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Affiliation(s)
- Maxime Garnault
- AgroParisTech, UMR BIOGER, INRAE, Université Paris-Saclay, Thiverval-Grignon, 78850, France
- MaIAGE, INRAE, Université Paris-Saclay, Jouy-en-Josas, 78350, France
| | - Clémentine Duplaix
- AgroParisTech, UMR BIOGER, INRAE, Université Paris-Saclay, Thiverval-Grignon, 78850, France
| | - Pierre Leroux
- AgroParisTech, UMR BIOGER, INRAE, Université Paris-Saclay, Thiverval-Grignon, 78850, France
| | | | - Olivier David
- MaIAGE, INRAE, Université Paris-Saclay, Jouy-en-Josas, 78350, France
| | - Anne-Sophie Walker
- AgroParisTech, UMR BIOGER, INRAE, Université Paris-Saclay, Thiverval-Grignon, 78850, France
| | - Florence Carpentier
- AgroParisTech, UMR BIOGER, INRAE, Université Paris-Saclay, Thiverval-Grignon, 78850, France
- MaIAGE, INRAE, Université Paris-Saclay, Jouy-en-Josas, 78350, France
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Rapid in situ quantification of the strobilurin resistance mutation G143A in the wheat pathogen Blumeria graminis f. sp. tritici. Sci Rep 2021; 11:4526. [PMID: 33633193 PMCID: PMC7907364 DOI: 10.1038/s41598-021-83981-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 02/08/2021] [Indexed: 11/25/2022] Open
Abstract
As the incidence of fungicide resistance in plant pathogens continues to increase, control of diseases and the management of resistance would be greatly aided by rapid diagnostic methods. Quantitative allele-specific PCR (ASqPCR) is an ideal technique for the in-field analysis of fungicide resistance as it can quantify the frequency of mutations in fungicide targets. We have applied this technique to the fungal pathogen Blumeria graminis f. sp. tritici (Bgt), the causal agent of wheat powdery mildew. In Australia, strobilurin-resistant Bgt was first discovered in 2016. Molecular analysis revealed a nucleotide transversion in the cytochrome b (cytb) gene in the cytochrome bc1 enzyme complex, resulting in a substitution of alanine for glycine at position 143 (G143A). We have developed an in-field ASqPCR assay that can quantify both the resistant (A143) and sensitive (G143) cytb alleles down to 1.67% in host and Bgt DNA mixtures, within 90 min of sample collection. The in situ analysis of samples collected during a survey in Tasmania revealed A143 frequencies ranging between 9–100%. Validation of the analysis with a newly developed laboratory based digital PCR assay found no significant differences between the two methods. We have successfully developed an in-field quantification method, for a strobilurin-resistant allele, by pairing the ASqPCR assay on a lightweight qPCR instrument with a quick DNA extraction method. The deployment of these type of methodologies in the field can contribute to the effective in-season management of fungicide resistance.
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Fungicide Resistance Evolution and Detection in Plant Pathogens: Plasmopara viticola as a Case Study. Microorganisms 2021; 9:microorganisms9010119. [PMID: 33419171 PMCID: PMC7825580 DOI: 10.3390/microorganisms9010119] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 12/31/2020] [Accepted: 01/04/2021] [Indexed: 02/06/2023] Open
Abstract
The use of single-site fungicides to control plant pathogens in the agroecosystem can be associated with an increased selection of resistance. The evolution of resistance represents one of the biggest challenges in disease control. In vineyards, frequent applications of fungicides are carried out every season for multiple years. The agronomic risk of developing fungicide resistance is, therefore, high. Plasmopara viticola, the causal agent of grapevine downy mildew, is a high risk pathogen associated with the development of fungicide resistance. P. viticola has developed resistance to most of the fungicide classes used and constitutes one of the most important threats for grapevine production. The goals of this review are to describe fungicide resistance evolution in P. viticola populations and how to conduct proper monitoring activities. Different methods have been developed for phenotyping and genotyping P. viticola for fungicide resistance and the different phases of resistance evolution and life cycles of the pathogen are discussed, to provide a full monitoring toolkit to limit the spread of resistance. A detailed revision of the available tools will help in shaping and harmonizing the monitoring activities between countries and organizations.
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Hagerty CH, Klein AM, Reardon CL, Kroese DR, Melle CJ, Graber KR, Mundt CC. Baseline and Temporal Changes in Sensitivity of Zymoseptoria tritici Isolates to Benzovindiflupyr in Oregon, U.S.A., and Cross-Sensitivity to Other SDHI Fungicides. PLANT DISEASE 2021; 105:169-174. [PMID: 33170771 DOI: 10.1094/pdis-10-19-2125-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB), a disease of wheat (Triticum aestivum) that results in significant yield loss worldwide. Z. tritici's life cycle, reproductive system, effective population size, and gene flow put it at high likelihood of developing fungicide resistance. Succinate dehydrogenase inhibitor (SDHI) fungicides (FRAC code 7) were not widely used to control STB in the Willamette Valley until 2016. Field isolates of Z. tritici collected in the Willamette Valley at dates spanning the introduction of SDHI (2015 to 2017) were screened for sensitivity to four SDHI active ingredients: benzovindiflupyr, penthiopyrad, fluxapyroxad, and fluindapyr. Fungicide sensitivity changes were determined by the fungicide concentration at which fungal growth is decreased by 50% (EC50) values. The benzovindiflupyr EC50 values increased significantly, indicating a reduction in sensitivity, following the adoption of SDHI fungicides in Oregon (P < 0.0001). Additionally, significant reduction in cross-sensitivity among SDHI active ingredients was also observed with a moderate and significant relationship between penthiopyrad and benzovindiflupyr (P = 0.0002) and a weak relationship between penthiopyrad and fluxapyroxad (P = 0.0482). No change in cross-sensitivity was observed with fluindapyr, which has not yet been labeled in the region. The results document a decrease in SDHI sensitivity in Z. tritici isolates following the introduction of the active ingredients to the Willamette Valley. The reduction in cross-sensitivity observed between SDHI active ingredients highlights the notion that careful consideration is required to manage fungicide resistance and suggests that within-group rotation is insufficient for resistance management.
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Affiliation(s)
- Christina H Hagerty
- Columbia Basin Agricultural Research Center, Oregon State University, Adams, OR 97810
| | - Ann M Klein
- Columbia Basin Agricultural Research Center, Oregon State University, Adams, OR 97810
| | - Catherine L Reardon
- Soil and Water Conservation Unit, United States Department of Agriculture-Agricultural Research Service, Adams, OR 97810
| | - Duncan R Kroese
- Columbia Basin Agricultural Research Center, Oregon State University, Adams, OR 97810
| | - Caroline J Melle
- Soil and Water Conservation Unit, United States Department of Agriculture-Agricultural Research Service, Adams, OR 97810
| | - Kaci R Graber
- Columbia Basin Agricultural Research Center, Oregon State University, Adams, OR 97810
| | - Christopher C Mundt
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97330
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Fones HN, Bebber DP, Chaloner TM, Kay WT, Steinberg G, Gurr SJ. Threats to global food security from emerging fungal and oomycete crop pathogens. ACTA ACUST UNITED AC 2020; 1:332-342. [PMID: 37128085 DOI: 10.1038/s43016-020-0075-0] [Citation(s) in RCA: 147] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 04/09/2020] [Indexed: 11/09/2022]
Abstract
Emerging fungal and oomycete pathogens infect staple calorie crops and economically important commodity crops, thereby posing a significant risk to global food security. Our current agricultural systems - with emphasis on intensive monoculture practices - and globalized markets drive the emergence and spread of new pathogens and problematic traits, such as fungicide resistance. Climate change further promotes the emergence of pathogens on new crops and in new places. Here we review the factors affecting the introduction and spread of pathogens and current disease control strategies, illustrating these with the historic example of the Irish potato famine and contemporary examples of soybean rust, wheat blast and blotch, banana wilt and cassava root rot. Our Review looks to the future, summarizing what we see as the main challenges and knowledge gaps, and highlighting the direction that research must take to face the challenge of emerging crop pathogens.
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Wang M, Xue J, Ma J, Feng X, Ying H, Xu H. Streptomyces lydicus M01 Regulates Soil Microbial Community and Alleviates Foliar Disease Caused by Alternaria alternata on Cucumbers. Front Microbiol 2020; 11:942. [PMID: 32499771 PMCID: PMC7243425 DOI: 10.3389/fmicb.2020.00942] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 04/20/2020] [Indexed: 01/22/2023] Open
Abstract
Due to the adverse effect on the environment caused by excessive use of chemical fertilizers, the development of sustainable agriculture attracts a growing demand of biological based fertilizers composed of living microorganisms. In this study, an Actinobacteria Streptomyces lydicus M01 was isolated from the rhizosphere soil of Pyrus calleryana. This strain effectively promoted the plant growth and suppressed a foliar disease caused by Alternaria alternata on cucumbers. S. lydicus M01 exhibited growth promoting characteristics such as phosphate solubilization, IAA secretion, siderophore and ACC deaminase production. Through Illumina sequencing of the 16S rRNA gene and ITS gene of the soil microbes, we found that the application of S. lydicus M01 altered the composition of the microbial community by promoting beneficial groups, including bacteria genera Pseudarthrobacter, Sphingomonas, Rhodanobacter, and Pseudomonas, fungi genera Fusicolla, Humicola, Solicoccozyma, and Paraphaeosphaeria. Most of these bacteria and eukaryotes exhibit positive effects on growth promotion, such as nutrient accumulation, auxin secretion, abiotic stress alleviation, biological control, or bioremediation. Furthermore, studies on the reactive oxygen species (ROS) level and antioxidants of cucumber leaves revealed that S. lydicus M01 treatment reduced the ROS accumulation and increased the activities of antioxidases related with ROS scavenging, which indicated an enhanced disease resistance of cucumbers under biotic stress. Thus, our results suggest that the application of S. lydicus M01 can systemically affect plant microbiome interactions and represent a promising sustainable solution to improve agricultural production instead of chemical fertilizers.
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Affiliation(s)
- Mingxuan Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Jian Xue
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Junjie Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Xiaohai Feng
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Hanjie Ying
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.,College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Hong Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.,College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
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Warneke B, Thiessen LD, Mahaffee WF. Effect of Fungicide Mobility and Application Timing on the Management of Grape Powdery Mildew. PLANT DISEASE 2020; 104:1167-1174. [PMID: 32053475 DOI: 10.1094/pdis-06-19-1285-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Grape powdery mildew (GPM) fungicide programs consist of 5 to 15 applications, depending on region or market, in an attempt to achieve the high fruit quality standards demanded by the market. Understanding how fungicides redistribute and targeting redistributing fungicide to critical crop phenological stages could improve fungicide protection of grape clusters. This study evaluated fungicide redistribution in grapevines from major fungicide groups labeled for GPM control. Translaminar and xylem redistribution was examined by placing fungicide-impregnated filter disks on the adaxial or abaxial leaf surface of detached leaves for 10 min and then incubating for 48 h before inoculating the abaxial surface with conidia. Vapor redistribution used Teflon disks sprayed with fungicides and placed on the abaxial leaf surface of detached leaves 48 h before inoculation. Disease development was rated 10 days later. Translaminar movement through calyptra was tested using flowering potted vines. All fungicides tested redistributed through at least one mechanism. Fungicide timing at critical phenological stages (early, mid, and late bloom) was assessed in small plots of cultivar Pinot noir vines. The application of trifloxystrobin, quinoxyfen, or fluopyram at different bloom stages showed that applications initiated at end of bloom resulted in the lowest berry infection probabilities of 0.073, 0.097, and 0.020, respectively. The results of this study suggest that integrating two carefully timed applications of redistributing fungicides initiated at end of bloom into a fungicide program may be an effective strategy for wine grape growers in western Oregon to produce fruit with low GPM infection.
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Affiliation(s)
- Brent Warneke
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | - Lindsey D Thiessen
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Walter F Mahaffee
- Horticultural Crops Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Corvallis, OR 97331
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Phan HTT, Jones DAB, Rybak K, Dodhia KN, Lopez-Ruiz FJ, Valade R, Gout L, Lebrun MH, Brunner PC, Oliver RP, Tan KC. Low Amplitude Boom-and-Bust Cycles Define the Septoria Nodorum Blotch Interaction. FRONTIERS IN PLANT SCIENCE 2020; 10:1785. [PMID: 32082346 PMCID: PMC7005668 DOI: 10.3389/fpls.2019.01785] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 12/20/2019] [Indexed: 05/30/2023]
Abstract
INTRODUCTION Septoria nodorum blotch (SNB) is a complex fungal disease of wheat caused by the Dothideomycete fungal pathogen Parastagonospora nodorum. The fungus infects through the use of necrotrophic effectors (NEs) that cause necrosis on hosts carrying matching dominant susceptibility genes. The Western Australia (WA) wheatbelt is a SNB "hot spot" and experiences significant under favorable conditions. Consequently, SNB has been a major target for breeders in WA for many years. MATERIALS AND METHODS In this study, we assembled a panel of 155 WA P. nodorum isolates collected over a 44-year period and compared them to 23 isolates from France and the USA using 28 SSR loci. RESULTS The WA P. nodorum population was clustered into five groups with contrasting properties. 80% of the studied isolates were assigned to two core groups found throughout the collection location and time. The other three non-core groups that encompassed transient and emergent populations were found in restricted locations and time. Changes in group genotypes occurred during periods that coincided with the mass adoption of a single or a small group of widely planted wheat cultivars. When introduced, these cultivars had high scores for SNB resistance. However, the field resistance of these new cultivars often declined over subsequent seasons prompting their replacement with new, more resistant varieties. Pathogenicity assays showed that newly emerged isolates non-core are more pathogenic than old isolates. It is likely that the non-core groups were repeatedly selected for increased virulence on the contemporary popular cultivars. DISCUSSION The low level of genetic diversity within the non-core groups, difference in virulence, low abundance, and restriction to limited locations suggest that these populations more vulnerable to a population crash when the cultivar was replaced by one that was genetically different and more resistant. We characterize the observed pattern as a low-amplitude boom-and-bust cycle in contrast with the classical high amplitude boom-and-bust cycles seen for biotrophic pathogens where the contrast between resistance and susceptibility is typically much greater. Implications of the results are discussed relating to breeding strategies for more sustainable SNB resistance and more generally for pathogens with NEs.
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Affiliation(s)
- Huyen T. T. Phan
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Darcy A. B. Jones
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Kasia Rybak
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Kejal N. Dodhia
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Francisco J. Lopez-Ruiz
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Romain Valade
- ARVALIS Institut du Végétal Avenue Lucien Brétignières, Bâtiment INRA Bioger, Thiverval-Grignon, France
| | - Lilian Gout
- UMR INRA Bioger Agro-ParisTech, Thiverval-Grignon, France
| | | | - Patrick C. Brunner
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Richard P. Oliver
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Kar-Chun Tan
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
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Newark MJ, Li P, Yang XP, Paret ML, Dufault NS. Comparing Stagonosporopsis spp. Fungicide Resistance Profiles in Florida and East China Cucurbit Production Systems. PLANT DISEASE 2020; 104:129-136. [PMID: 31747352 DOI: 10.1094/pdis-02-19-0370-re] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Gummy stem blight, caused by Stagonosporopsis spp., is a major disease of cucurbits in the United States and China that is managed primarily through the use of fungicides. The objective of this study was to monitor and compare the recent fungicide resistance profiles of Stagonosporopsis spp. in Florida open-field and East China protected-structure production systems. Isolates of Stagonosporopsis spp. were evaluated for sensitivity to the commonly used fungicides azoxystrobin, boscalid, tebuconazole, and thiophanate-methyl at discriminatory rates of 0.096, 0.034, 0.128, and 100 mg/liter, respectively. Isolates were collected from Jiangsu, Jiangxi, Zhejiang, and Anhui provinces in China (n = 69), 12 counties in Florida (n = 89), and one county in Georgia (n = 6). More than 50% of isolates from Florida and East China were resistant to thiophanate-methyl. Boscalid resistance was detected in both isolate collections but was two times more frequent in China. Resistance to azoxystrobin was detected in 66% of isolates in Florida but only 7% in China. Tebuconazole was effective in controlling the mycelia growth of Stagonosporopsis spp. in both collections. The results indicate that both production systems currently face similar challenges related to the development of fungicide resistance in Stagonosporopsis spp. However, the resistance profiles are unique for both production systems.
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Affiliation(s)
- Mason J Newark
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611-0680, U.S.A
| | - Pingfang Li
- Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xing-Ping Yang
- Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Mathews L Paret
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611-0680, U.S.A
- North Florida Research and Education Center, University of Florida, Quincy, FL 32351, U.S.A
| | - Nicholas S Dufault
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611-0680, U.S.A
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Meyers E, Arellano C, Cowger C. Sensitivity of the U.S. Blumeria graminis f. sp. tritici Population to Demethylation Inhibitor Fungicides. PLANT DISEASE 2019; 103:3108-3116. [PMID: 31657998 DOI: 10.1094/pdis-04-19-0715-re] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, is managed in the United States with cultivar resistance and foliar fungicides. Despite high levels of fungicide sensitivity in other cereal mildew populations, fungicide sensitivity of U.S. B. graminis f. sp. tritici has never been evaluated. Almost 400 B. graminis f. sp. tritici isolates were collected from 15 U.S. states over 2 years and phenotyped for sensitivity to two widely used demethylation inhibitor (DMI) fungicides, tebuconazole and prothioconazole. A large range of sensitivity to both DMIs was observed, with more insensitive isolates originating from the eastern United States (Great Lakes, Mid-Atlantic, and Southeast regions) and more sensitive isolates from central states (Plains region, Arkansas, and Missouri). Cross-resistance was indicated by a positive although weak association between tebuconazole and prothioconazole sensitivities at all levels of analysis (EC50 values, P < 0.0001). A possible fitness cost was also associated with prothioconazole insensitivity (P = 0.0307) when analyzed at the state population level. This is the first assessment of fungicide sensitivity in the U.S. B. graminis f. sp. tritici population, and it produced evidence of regional selection for reduced DMI efficacy. The observation of reduced sensitivity to DMI fungicides in the eastern United States underlines the importance of rotating between chemistry classes to maintain the effectiveness of DMIs in U.S. wheat production. Although cross-resistance was demonstrated, variability in the relationship of EC50 values for tebuconazole and prothioconazole also suggests that multiple mechanisms influence B. graminis f. sp. tritici isolate responses to these two DMI fungicides.
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Affiliation(s)
- Emily Meyers
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Consuelo Arellano
- Department of Statistics, North Carolina State University, Raleigh, NC 27695
| | - Christina Cowger
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
- United States Department of Agriculture, Agricultural Research Service, Raleigh, NC 27695
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Li HX, Nuckols TA, Harris D, Stevenson KL, Brewer MT. Differences in fungicide resistance profiles and multiple resistance to a quinone-outside inhibitor (QoI), two succinate dehydrogenase inhibitors (SDHI), and a demethylation inhibitor (DMI) for two Stagonosporopsis species causing gummy stem blight of cucurbits. PEST MANAGEMENT SCIENCE 2019; 75:3093-3101. [PMID: 30924240 DOI: 10.1002/ps.5426] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 02/08/2019] [Accepted: 03/28/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Gummy stem blight (GSB) is a devastating disease of cucurbits that has been effectively managed with fungicide applications. However, the Stagonosporopsis spp. that cause GSB have rapidly evolved resistance to multiple classes of fungicides. To better understand the evolution and persistence of fungicide resistance in field populations, resistance profiles of unique and clonal genotypes of 113 Stagonosporopsis citrulli and 19 S. caricae isolates to four different fungicides were determined based on in vitro mycelial growth assays and molecular markers based on genes encoding fungicide targets. RESULTS All 19 S. caricae isolates screened were resistant to tebuconazole and azoxystrobin, and sensitive to boscalid and fluopyram. All 113 S. citrulli isolates were sensitive to tebuconazole and sensitive to fluopyram, with one exception that was fluopyram-resistant. All isolates of S. citrulli except two were resistant to azoxystrobin. Phenotypic differences in response to boscalid were detected among S. citrulli isolates, but the phenotypes were not associated with multilocus genotypes (MLG) determined by 16 microsatellite loci. Additionally, isolates sharing the same MLG varied by SdhB genotype. A unique mutation of I229V in SdhB, a target of succinate dehydrogenase inhibitor fungicides, was detected for the fluopyram-resistant isolate of S. citrulli. CONCLUSION Both the lack of association of fungicide resistance profiles with genetic similarity of isolates based on microsatellite loci and the finding that widely distributed MLG varied in fungicide resistance profiles suggest that independent evolutionary events for resistance to boscalid have likely occurred. Frequent genetic recombination within populations may be responsible for resistance to multiple fungicides. This study provides useful information for effectively managing both species of GSB fungi present in the southeastern USA and understanding the evolution of fungicide resistance within populations of plant-pathogenic fungi. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Hao-Xi Li
- Department of Plant Pathology, University of Georgia, Athens, GA, USA
| | - Thomas A Nuckols
- Department of Plant Pathology, University of Georgia, Athens, GA, USA
| | - Devon Harris
- Department of Plant Pathology, University of Georgia, Athens, GA, USA
| | | | - Marin T Brewer
- Department of Plant Pathology, University of Georgia, Athens, GA, USA
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40
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Figueiredo GVC, Fantin LH, Canteri MG, Ferreira da Rocha JC, Filho DDSJ. A Bayesian Probability Model Can Simulate the Knowledge of Soybean Rust Researchers to Optimize the Application of Fungicides. INTERNATIONAL JOURNAL OF AGRICULTURAL AND ENVIRONMENTAL INFORMATION SYSTEMS 2019. [DOI: 10.4018/ijaeis.2019100103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Asian rust is the main soybean disease in Brazil, causing up to 80% of yield reduction. The use of fungicides is the main form of control; however, due to farmer's concern with outbreaks many unnecessary applications are performed. The present study aims to verify the usefulness of a probability model to estimate the timing and the number of fungicides sprays required to control Asian soybean rust, using Bayesian networks and knowledge engineering. The model was developed through interviews with rust researchers and a literature review. The Bayesian network was constructed with the GeNIe 2.0 software. The validation process was performed by 42 farmers and 10 rust researchers, using 28 test cases. Among the 28 tested cases, generated by the system, the agreement with the model was 47.5% for the farmers and 89.3% for the rust researchers. In general, the farmers overestimate the number. The results showed that the Bayesian network has accurately represented the knowledge of the expert, and also could help the farmers to avoid the unnecessary applications.
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41
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Zhang Q, Feng R, Zheng Q, Li J, Liu Z, Zhao D, Meng Y, Tian Y, Li W, Ma X, Wang S, Shan W. Population Genetic Analysis of Phytophthora parasitica From Tobacco in Chongqing, Southwestern China. PLANT DISEASE 2019; 103:2599-2605. [PMID: 31339441 DOI: 10.1094/pdis-05-18-0879-re] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Tobacco black shank, caused by Phytophthora parasitica, is one of the most notorious tobacco diseases and causes huge economic losses worldwide. Understanding the genetic variation of P. parasitica populations is essential to the development of disease control measures. In this research, 210 simple sequence repeat (SSR) markers for P. parasitica were identified, 10 of which were polymorphic among nine reference strains. We further performed population genetic analysis of 245 P. parasitica isolates randomly collected from tobacco fields in Chongqing for mating type, molecular variation at 14 SSR loci (four of which were identified previously), and sensitivity to the fungicide metalaxyl. The results showed that the A2 mating type was dominant and no A1 mating type isolate was discovered. SSR genotyping distinguished 245 P. parasitica isolates into 46 genotypes, four of which were dominant in the population. Low genotypic diversity and excess heterozygosity were common in nearly all of the populations from Chongqing. Population analysis showed that no differentiation existed among different populations. All isolates tested were highly sensitive to metalaxyl. Taken together, our results showed that the P. parasitica populations from tobacco fields in Chongqing belonged to a clonal lineage and were highly sensitive to metalaxyl.
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Affiliation(s)
- Qiang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Ruirui Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Qing Zheng
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Jinyang Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Zhirou Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Dan Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yuling Meng
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yuee Tian
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Weiwei Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xiaowei Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Shuang Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Weixing Shan
- State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
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42
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Krylov IB, Budnikov AS, Lopat'eva ER, Nikishin GI, Terent'ev AO. Mild Nitration of Pyrazolin-5-ones by a Combination of Fe(NO 3 ) 3 and NaNO 2 : Discovery of a New Readily Available Class of Fungicides, 4-Nitropyrazolin-5-ones. Chemistry 2019; 25:5922-5933. [PMID: 30834586 DOI: 10.1002/chem.201806172] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/24/2019] [Indexed: 02/02/2023]
Abstract
4-Nitropyrazolin-5-ones have been synthesized by the nitration of pyrazolin-5-ones at room temperature by employing the Fe(NO3 )3 /NaNO2 system. The method demonstrated selectivity towards the 4-position of pyrazolin-5-ones even in the presence of NPh and allyl substituents, which are sensitive to nitration. It was shown that other systems containing FeIII and nitrites, namely Fe(NO3 )3 /tBuONO, Fe(ClO4 )3 /NaNO2 , and Fe(ClO4 )3 /tBuONO, were also effective. Presumably, FeIII oxidizes the nitrite (NaNO2 or tBuONO) to form the NO2 free radical, which serves as the nitrating agent for pyrazolin-5-ones. The synthesized 4-nitropyrazolin-5-ones were discovered to be a new class of fungicides. Their in vitro activities against phytopathogenic fungi were found comparable or even superior to those of commercial fungicides (fluconazole, clotrimazole, triadimefon, and kresoxim-methyl). These results represent a promising starting point for the development of a new type of plant protection agents that can be easily synthesized from widely available reagents.
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Affiliation(s)
- Igor B Krylov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of, Sciences, 47 Leninsky prosp., Moscow, 119991, Russian Federation.,All-Russian Research Institute for Phytopathology, B. Vyazyomy, Moscow Region, 143050, Russian Federation
| | - Alexander S Budnikov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of, Sciences, 47 Leninsky prosp., Moscow, 119991, Russian Federation.,All-Russian Research Institute for Phytopathology, B. Vyazyomy, Moscow Region, 143050, Russian Federation.,Mendeleev University of Chemical Technology of Russia, 9 Miusskaya sq., Moscow, 125047, Russian Federation
| | - Elena R Lopat'eva
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of, Sciences, 47 Leninsky prosp., Moscow, 119991, Russian Federation.,Mendeleev University of Chemical Technology of Russia, 9 Miusskaya sq., Moscow, 125047, Russian Federation
| | - Gennady I Nikishin
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of, Sciences, 47 Leninsky prosp., Moscow, 119991, Russian Federation
| | - Alexander O Terent'ev
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of, Sciences, 47 Leninsky prosp., Moscow, 119991, Russian Federation.,All-Russian Research Institute for Phytopathology, B. Vyazyomy, Moscow Region, 143050, Russian Federation.,Mendeleev University of Chemical Technology of Russia, 9 Miusskaya sq., Moscow, 125047, Russian Federation
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43
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Kurenbach B, Hill AM, Godsoe W, van Hamelsveld S, Heinemann JA. Agrichemicals and antibiotics in combination increase antibiotic resistance evolution. PeerJ 2018; 6:e5801. [PMID: 30345180 PMCID: PMC6188010 DOI: 10.7717/peerj.5801] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 09/21/2018] [Indexed: 12/18/2022] Open
Abstract
Antibiotic resistance in our pathogens is medicine's climate change: caused by human activity, and resulting in more extreme outcomes. Resistance emerges in microbial populations when antibiotics act on phenotypic variance within the population. This can arise from either genotypic diversity (resulting from a mutation or horizontal gene transfer), or from differences in gene expression due to environmental variation, referred to as adaptive resistance. Adaptive changes can increase fitness allowing bacteria to survive at higher concentrations of antibiotics. They can also decrease fitness, potentially leading to selection for antibiotic resistance at lower concentrations. There are opportunities for other environmental stressors to promote antibiotic resistance in ways that are hard to predict using conventional assays. Exploiting our previous observation that commonly used herbicides can increase or decrease the minimum inhibitory concentration (MIC) of different antibiotics, we provide the first comprehensive test of the hypothesis that the rate of antibiotic resistance evolution under specified conditions can increase, regardless of whether a herbicide increases or decreases the antibiotic MIC. Short term evolution experiments were used for various herbicide and antibiotic combinations. We found conditions where acquired resistance arises more frequently regardless of whether the exogenous non-antibiotic agent increased or decreased antibiotic effectiveness. This is attributed to the effect of the herbicide on either MIC or the minimum selective concentration (MSC) of a paired antibiotic. The MSC is the lowest concentration of antibiotic at which the fitness of individuals varies because of the antibiotic, and is lower than MIC. Our results suggest that additional environmental factors influencing competition between bacteria could enhance the ability of antibiotics to select antibiotic resistance. Our work demonstrates that bacteria may acquire antibiotic resistance in the environment at rates substantially faster than predicted from laboratory conditions.
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Affiliation(s)
- Brigitta Kurenbach
- School of Biological Sciences and Centre for Integrated Research in Biosafety and Centre for Integrative Ecology, University of Canterbury, Christchurch, New Zealand
| | - Amy M Hill
- School of Biological Sciences and Centre for Integrated Research in Biosafety and Centre for Integrative Ecology, University of Canterbury, Christchurch, New Zealand
| | - William Godsoe
- Bio-Protection Centre, Lincoln University, Lincoln, New Zealand
| | - Sophie van Hamelsveld
- School of Biological Sciences and Centre for Integrated Research in Biosafety and Centre for Integrative Ecology, University of Canterbury, Christchurch, New Zealand
| | - Jack A Heinemann
- School of Biological Sciences and Centre for Integrated Research in Biosafety and Centre for Integrative Ecology, University of Canterbury, Christchurch, New Zealand
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44
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Song XS, Gu KX, Duan XX, Xiao XM, Hou YP, Duan YB, Wang JX, Zhou MG. A myosin5 dsRNA that reduces the fungicide resistance and pathogenicity of Fusarium asiaticum. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 150:1-9. [PMID: 30195381 DOI: 10.1016/j.pestbp.2018.07.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 06/20/2018] [Accepted: 07/12/2018] [Indexed: 05/23/2023]
Abstract
Fungal resistance to fungicides is a serious challenge in crop protection. Although strategies have been found to prevent the development of fungicide resistance, rare strategy has been found to quickly reduce such resistance once it has occurred. We demonstrate that the application of dsRNAs, which inhibit the expression of the phenamacril (fungicide JS399-19) target gene-Myosin 5 (Myo5) in Fusarium, decreased F. asiaticum resistance to phenamacril and infection. RNAi molecules derived from different regions of Myo5 gene had different effects on phenamacril-resistance. Myo5-8 (one of Myo5 segments) exhibited great and stable effect on phenamacril-resistant reduction both in vivo and in vitro. Myo5 mRNA and protein were both reduced when mycelium was treated with Myo5-8 dsRNA. After a mixture of Myo5-8 dsRNA and phenamacril treatment, plants can highly control the infection of phenamacril-resistant strain. The antifungal activity of Myo5-8 dsRNA plus phenamacril effected longer than a single Myo5-8 dsRNA. In addition, no off-target sequences were found in wheat and/or other plant and animal species for Myo5-8 dsRNA sequence. Our findings suggest a new strategy for fungicide resistant reduction and for designing new fungicides to control pathogens which easily develop fungicide resistance.
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Affiliation(s)
- Xiu-Shi Song
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Jiangsu Province, Nanjing 210095, China
| | - Kai-Xin Gu
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Jiangsu Province, Nanjing 210095, China
| | - Xiao-Xin Duan
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Jiangsu Province, Nanjing 210095, China
| | - Xue-Mei Xiao
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Jiangsu Province, Nanjing 210095, China
| | - Yi-Ping Hou
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Jiangsu Province, Nanjing 210095, China
| | - Ya-Bing Duan
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Jiangsu Province, Nanjing 210095, China
| | - Jian-Xin Wang
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Jiangsu Province, Nanjing 210095, China
| | - Ming-Guo Zhou
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Jiangsu Province, Nanjing 210095, China.
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45
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Hawkins NJ, Fraaije BA. Fitness Penalties in the Evolution of Fungicide Resistance. ANNUAL REVIEW OF PHYTOPATHOLOGY 2018; 56:339-360. [PMID: 29958074 DOI: 10.1146/annurev-phyto-080417-050012] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The evolution of resistance poses an ongoing threat to crop protection. Fungicide resistance provides a selective advantage under fungicide selection, but resistance-conferring mutations may also result in fitness penalties, resulting in an evolutionary trade-off. These penalties may result from the functional constraints of an evolving target site or from the resource allocation costs of overexpression or active transport. The extent to which such fitness penalties are present has important implications for resistance management strategies, determining whether resistance persists or declines between treatments, and for resistance risk assessments for new modes of action. Experimental results have proven variable, depending on factors such as temperature, nutrient status, osmotic or oxidative stress, and pathogen life-cycle stage. Functional genetics tools allow pathogen genetic background to be controlled, but this in turn raises the question of epistatic interactions. Combining fitness penalties under various conditions into a field-realistic scenario poses an important future challenge.
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Affiliation(s)
- N J Hawkins
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom;
| | - B A Fraaije
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom;
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46
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Elderfield JAD, Lopez-Ruiz FJ, van den Bosch F, Cunniffe NJ. Using Epidemiological Principles to Explain Fungicide Resistance Management Tactics: Why do Mixtures Outperform Alternations? PHYTOPATHOLOGY 2018; 108:803-817. [PMID: 29377769 DOI: 10.1094/phyto-08-17-0277-r] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Whether fungicide resistance management is optimized by spraying chemicals with different modes of action as a mixture (i.e., simultaneously) or in alternation (i.e., sequentially) has been studied by experimenters and modelers for decades. However, results have been inconclusive. We use previously parameterized and validated mathematical models of wheat Septoria leaf blotch and grapevine powdery mildew to test which tactic provides better resistance management, using the total yield before resistance causes disease control to become economically ineffective ("lifetime yield") to measure effectiveness. We focus on tactics involving the combination of a low-risk and a high-risk fungicide, and the case in which resistance to the high-risk chemical is complete (i.e., in which there is no partial resistance). Lifetime yield is then optimized by spraying as much low-risk fungicide as is permitted, combined with slightly more high-risk fungicide than needed for acceptable initial disease control, applying these fungicides as a mixture. That mixture rather than alternation gives better performance is invariant to model parameterization and structure, as well as the pathosystem in question. However, if comparison focuses on other metrics, e.g., lifetime yield at full label dose, either mixture or alternation can be optimal. Our work shows how epidemiological principles can explain the evolution of fungicide resistance, and also highlights a theoretical framework to address the question of whether mixture or alternation provides better resistance management. It also demonstrates that precisely how spray tactics are compared must be given careful consideration. [Formula: see text] Copyright © 2018 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .
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Affiliation(s)
- James A D Elderfield
- First and fourth authors: Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, United Kingdom; second author: Curtin University, Centre for Crop and Disease Management, Department of Environment and Agriculture, Bentley, WA 6845, Australia; and third author: Rothamsted Research, Harpenden, AL5 2JQ, United Kingdom
| | - Francisco J Lopez-Ruiz
- First and fourth authors: Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, United Kingdom; second author: Curtin University, Centre for Crop and Disease Management, Department of Environment and Agriculture, Bentley, WA 6845, Australia; and third author: Rothamsted Research, Harpenden, AL5 2JQ, United Kingdom
| | - Frank van den Bosch
- First and fourth authors: Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, United Kingdom; second author: Curtin University, Centre for Crop and Disease Management, Department of Environment and Agriculture, Bentley, WA 6845, Australia; and third author: Rothamsted Research, Harpenden, AL5 2JQ, United Kingdom
| | - Nik J Cunniffe
- First and fourth authors: Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, United Kingdom; second author: Curtin University, Centre for Crop and Disease Management, Department of Environment and Agriculture, Bentley, WA 6845, Australia; and third author: Rothamsted Research, Harpenden, AL5 2JQ, United Kingdom
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47
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Zulak KG, Cox BA, Tucker MA, Oliver RP, Lopez-Ruiz FJ. Improved Detection and Monitoring of Fungicide Resistance in Blumeria graminis f. sp. hordei With High-Throughput Genotype Quantification by Digital PCR. Front Microbiol 2018; 9:706. [PMID: 29706938 PMCID: PMC5908980 DOI: 10.3389/fmicb.2018.00706] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 03/27/2018] [Indexed: 01/09/2023] Open
Abstract
The increased occurrence of triazole fungicide resistant strains of Blumeria graminis f. sp. hordei (Bgh) is an economic concern for the barley industry in Australia and elsewhere. High levels of resistance to triazoles in the field are caused by two separate point mutations in the Cyp51 gene, Y136F and S509T. Early detection of these mutations arising in pathogen field populations is important as this allows time for changes in fungicide practices to be adopted, thus mitigating potential yield losses due to fungicide failure and preventing the resistance from becoming dominant. A digital PCR (dPCR) assay has been developed for the detection and quantification of the Y136F and S509T mutations in the Bgh Cyp51 gene. Mutation levels were quantifiable as low as 0.2% in genomic DNA extractions and field samples. This assay was applied to the high throughput screening of Bgh field and bait trial samples from barley growing regions across Australia in the 2015 and 2016 growing seasons and identified the S509T mutation for the first time in the Eastern states of Australia. This is the first report on the use of digital PCR technology for fungicide resistance detection and monitoring in agriculture. Here we describe the potential application of dPCR for the screening of fungicide resistance mutations in a network of specifically designed bait trials. The combination of these two tools constitute an early warning system for the development of fungicide resistance that allows for the timely adjustment of management practices.
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Affiliation(s)
- Katherine G Zulak
- The Fungicide Resistance Group, Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - Belinda A Cox
- The Fungicide Resistance Group, Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - Madeline A Tucker
- The Fungicide Resistance Group, Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - Richard P Oliver
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
| | - Francisco J Lopez-Ruiz
- The Fungicide Resistance Group, Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, Australia
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Carolan K, Helps J, van den Berg F, Bain R, Paveley N, van den Bosch F. Extending the durability of cultivar resistance by limiting epidemic growth rates. Proc Biol Sci 2018; 284:rspb.2017.0828. [PMID: 28931732 DOI: 10.1098/rspb.2017.0828] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 08/10/2017] [Indexed: 11/12/2022] Open
Abstract
Cultivar resistance is an essential part of disease control programmes in many agricultural systems. The use of resistant cultivars applies a selection pressure on pathogen populations for the evolution of virulence, resulting in loss of disease control. Various techniques for the deployment of host resistance genes have been proposed to reduce the selection for virulence, but these are often difficult to apply in practice. We present a general technique to maintain the effectiveness of cultivar resistance. Derived from classical population genetics theory; any factor that reduces the population growth rates of both the virulent and avirulent strains will reduce selection. We model the specific example of fungicide application to reduce the growth rates of virulent and avirulent strains of a pathogen, demonstrating that appropriate use of fungicides reduces selection for virulence, prolonging cultivar resistance. This specific example of chemical control illustrates a general principle for the development of techniques to manage the evolution of virulence by slowing epidemic growth rates.
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Affiliation(s)
| | - Joe Helps
- Rothamsted Research, Harpenden AL5 5LS, UK
| | | | | | - Neil Paveley
- ADAS, High Mowthorpe, Malton, North Yorkshire YO17 8BP, UK
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Blake JJ, Gosling P, Fraaije BA, Burnett FJ, Knight SM, Kildea S, Paveley ND. Changes in field dose-response curves for demethylation inhibitor (DMI) and quinone outside inhibitor (QoI) fungicides against Zymoseptoria tritici, related to laboratory sensitivity phenotyping and genotyping assays. PEST MANAGEMENT SCIENCE 2018; 74:302-313. [PMID: 28881414 DOI: 10.1002/ps.4725] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 08/24/2017] [Accepted: 08/30/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Insensitivity of Zymoseptoria tritici to demethylation inhibitor (DMI) and quinone outside inhibitor (QoI) fungicides has been widely reported from laboratory studies, but the relationships between laboratory sensitivity phenotype or target site genotype and field efficacy remain uncertain. This article reports field experiments quantifying dose-response curves, and investigates the relationships between field performance and in vitro half maximal effective concentration (EC50 ) values for DMIs, and the frequency of the G143A substitution conferring QoI resistance. RESULTS Data were analysed from 83 field experiments over 21 years. Response curves were fitted, expressed as percentage control, rising towards an asymptote with increasing dose. Decline in DMI efficacy over years was associated with a decrease in the asymptote, and reduced curvature. Field ED50 values were positively related to in vitro EC50 values for isolates of Z. tritici collected over a 14-year period. Loss of QoI efficacy was expressed through a change in asymptote. Increasing frequency of G143A was associated with changes in field dose-response asymptotes. CONCLUSION New resistant strains are often detected by resistance monitoring and laboratory phenotyped/genotyped before changes in field performance are detected. The relationships demonstrated here between laboratory tests and field performance could aid translation between laboratory and field for other fungicide groups. © 2017 Society of Chemical Industry.
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Affiliation(s)
| | - Paul Gosling
- Agriculture and Horticulture Development Board, Stoneleigh Park, Kenilworth, UK
| | - Bart A Fraaije
- Rothamsted Research, Biointeractions and Crop Protection Department, Harpenden, UK
| | - Fiona J Burnett
- Scotland's Rural College (SRUC), King's Buildings, Edinburgh, UK
| | | | - Steven Kildea
- Department of Crop Science, Teagasc, Carlow, Republic of Ireland
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Pethybridge SJ, Vaghefi N, Kikkert JR. Management of Cercospora Leaf Spot in Conventional and Organic Table Beet Production. PLANT DISEASE 2017; 101:1642-1651. [PMID: 30677334 DOI: 10.1094/pdis-04-17-0528-re] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Cercospora leaf spot (CLS; Cercospora beticola) is the most important foliar disease affecting table beet. Epidemics occur annually and fungicides extend the survival of foliage to enable mechanized harvest. However, a high frequency of strobilurin-resistant C. beticola isolates necessitates the identification of fungicides with different modes of action for tactical rotation. There is also substantial demand for organically produced table beet, for which synthetic fungicides are prohibited. Five small-plot, replicated field trials were conducted over two years to evaluate conventional and Organic Materials Review Institute (OMRI)-listed products for CLS control in table beet cv. Ruby Queen at Geneva and Ithaca, New York. Benzovindiflupyr + difenoconazole significantly reduced temporal disease progress (measured by the area under the disease progress stairs; AUDPS) by 86.7 to 97.3% compared with nontreated plots, and mean survival time of leaves was significantly extended. The demethylation inhibitor, propiconazole, also provided significant disease control in two trials in 2016. Disease severity in plots treated with succinate dehydrogenase inhibitors (boscalid, fluxapyroxad + pyraclostrobin, and penthiopyrad) was significantly decreased compared with nontreated plots but less than other fungicides. Efficacious fungicides significantly increased the dry weight of foliage but did not significantly affect the dry weight of roots, and root shoulder diameter. The enhanced longevity of leaves and increased dry weight of foliage may extend opportunities for mechanized harvesting without deleteriously affecting root yield parameters which are strictly regulated for the processing markets. In two trials, copper octanoate + Bacillus amyloliquefaciens strain D747 (as Cueva + Double Nickel LC) resulted in significantly improved disease control in comparison with application of either product alone and provided comparable and reproducible disease control equivalent to conventional fungicides at both locations. The implications of these findings for CLS control in conventional and organic table beet production systems are discussed.
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Affiliation(s)
- Sarah J Pethybridge
- School of Integrative Plant Science, Plant Pathology & Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456
| | - Niloofar Vaghefi
- School of Integrative Plant Science, Plant Pathology & Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456
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