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Miller T, Richmond M, Vann M, Hansen Z. Sensitivity of Phytophthora nicotianae in Tennessee and North Carolina to Mefenoxam, Oxathiapiprolin, Mandipropamid, and Fluopicolide. PLANT DISEASE 2024; 108:1612-1620. [PMID: 38127637 DOI: 10.1094/pdis-04-23-0632-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: 12/23/2023]
Abstract
Phytophthora nicotianae causes devastating disease in a range of hosts, including tobacco (N. tabacum L.), tomato, citrus, strawberry, and numerous ornamentals. Black shank, caused by P. nicotianae, is the most economically important disease to tobacco production in Tennessee and North Carolina. Black shank management includes the use of resistant cultivars, crop rotation, and fungicides. Fungicide resistance is a concern for black shank management due to the limited number of active ingredients available and the repeated exposure of pathogen populations to these products. In vitro fungicide sensitivity assays were conducted on 155 P. nicotianae isolates collected in Tennessee and North Carolina in 2021 and 2022 to determine their EC50 values for oxathiapiprolin, mandipropamid, and fluopicolide. The P. nicotianae was isolated predominantly from burley, dark, and flue-cured tobacco showing symptoms of black shank as well as tomato with buckeye rot symptoms. A discriminatory dose was used to determine each isolate's sensitivity to mefenoxam in 2021 and 2022. In 2021, EC50 values were determined for oxathiapiprolin, mandipropamid, and fluopicolide. In 2022, discriminatory doses based on EC75 values were used to determine each isolate's sensitivity to these fungicides. All isolates from the 2 years were sensitive to mefenoxam, mandipropamid, and fluopicolide. One isolate in 2022 was moderately sensitive to oxathiapiprolin, while all other isolates were sensitive.
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Affiliation(s)
- Taylor Miller
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996
| | - Mitchell Richmond
- Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996
| | - Matthew Vann
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695
| | - Zachariah Hansen
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996
- Emerging Pests and Pathogens Research Unit, Robert W. Holley Center for Agriculture and Health, Agricultural Research Service, United States Department of Agriculture, Ithaca, NY 14850
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Dhali R, Dey T, Tewari S, Roy SG. A Survey of Phytophthora spp. in Eastern Indian Nurseries and Their Sensitivity to Six Oomycete-Targeted Commercial Fungicides. PLANT DISEASE 2024; 108:486-501. [PMID: 37498632 DOI: 10.1094/pdis-10-22-2341-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: 07/28/2023]
Abstract
A survey of the flori-horticultural nurseries in eastern India found Phytophthora nicotianae to be the most widespread Phytophthora species associated with different foliar symptoms of nursery plants and identified the presence of P. palmivora in eastern Indian nurseries for the first time. The survey also led to the first worldwide finding of P. nicotianae on Dipteracanthus prostratus (Poir.) Nees; Ocimum tenuiflorum L. (syn. Ocimum sanctum L.); Philodendron xanadu Croat, Mayo & J. Boos; and Pyrostegia venusta (Ker-Gawl.) Miers and P. palmivora on Episcia cupreata (Hook.) Hanst., as well as the first report from India of P. nicotianae on Spathiphyllum wallisii Regel; Anthurium andraeanum Linden ex André; and Adenium obesum (Forsk.) Roem. & Schult. Sensitivity to commercial fungicides Glazer 35WS, Rallis India (metalaxyl, FRAC code 4); Ridomil Gold, Syngenta (mefenoxam + mancozeb); Revus, Syngenta (mandipropamid, FRAC code 40); Aliette Bayer (fosetyl-Al, FRAC code 33); Acrobat, BASF (dimethomorph, FRAC code 40); and Amistar, Syngenta (azoxystrobin, FRAC code 11) was analyzed, showing EC50 values ranging from 0.75 to 16.39 ppm, 0.74 to 1.45 ppm, 2.43 to 17.21 ppm, 63.81 to 327.31 ppm, 8.88 to 174.69 ppm, and 0.1 to 1.13 ppm, respectively, with no cross-resistance of the isolates to the fungicides. The baseline information produced about these Phytophthora spp. from ornamental and horticultural host associations could help prevent the pathogens from becoming primary drivers of new disease outbreaks and their large-scale distribution beyond their natural endemic ranges.
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Affiliation(s)
- Rikta Dhali
- Department of Botany, West Bengal State University, Barasat, Kolkata 700126, India
| | - Tanmoy Dey
- Department of Botany, West Bengal State University, Barasat, Kolkata 700126, India
| | | | - Sanjoy Guha Roy
- Department of Botany, West Bengal State University, Barasat, Kolkata 700126, India
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Quesada-Ocampo LM, Parada-Rojas CH, Hansen Z, Vogel G, Smart C, Hausbeck MK, Carmo RM, Huitema E, Naegele RP, Kousik CS, Tandy P, Lamour K. Phytophthora capsici: Recent Progress on Fundamental Biology and Disease Management 100 Years After Its Description. ANNUAL REVIEW OF PHYTOPATHOLOGY 2023; 61:185-208. [PMID: 37257056 DOI: 10.1146/annurev-phyto-021622-103801] [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: 06/02/2023]
Abstract
Phytophthora capsici is a destructive oomycete pathogen of vegetable, ornamental, and tropical crops. First described by L.H. Leonian in 1922 as a pathogen of pepper in New Mexico, USA, P. capsici is now widespread in temperate and tropical countries alike. Phytophthora capsici is notorious for its capability to evade disease management strategies. High genetic diversity allows P. capsici populations to overcome fungicides and host resistance, the formation of oospores results in long-term persistence in soils, zoospore differentiation in the presence of water increases epidemic potential, and a broad host range maximizes economic losses and limits the effectiveness of crop rotation. The severity of disease caused by P. capsici and management challenges have led to numerous research efforts in the past 100 years. Here, we discuss recent findings regarding the biology, genetic diversity, disease management, fungicide resistance, host resistance, genomics, and effector biology of P. capsici.
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Affiliation(s)
- L M Quesada-Ocampo
- Department of Entomology and Plant Pathology and NC Plant Sciences Initiative, North Carolina State University, Raleigh, North Carolina, USA;
| | - C H Parada-Rojas
- Department of Entomology and Plant Pathology and NC Plant Sciences Initiative, North Carolina State University, Raleigh, North Carolina, USA;
| | - Z Hansen
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, USA
| | - G Vogel
- School of Integrative Plant Science, Cornell University, Geneva, New York, USA
| | - C Smart
- School of Integrative Plant Science, Cornell University, Geneva, New York, USA
| | - M K Hausbeck
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, Michigan, USA
| | - R M Carmo
- Division of Plant Sciences, University of Dundee, Dundee, United Kingdom
| | - E Huitema
- Division of Plant Sciences, University of Dundee, Dundee, United Kingdom
- James Hutton Institute, Invergowrie, Dundee, United Kingdom
| | - R P Naegele
- Sugarbeet and Bean Research Unit, USDA, ARS, East Lansing, Michigan, USA
| | - C S Kousik
- US Vegetable Laboratory, USDA, ARS, Charleston, South Carolina, USA
| | - P Tandy
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, USA
| | - K Lamour
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, USA
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Sanogo S, Lamour K, Kousik CS, Lozada DN, Parada-Rojas CH, Quesada-Ocampo LM, Wyenandt CA, Babadoost M, Hausbeck MK, Hansen Z, Ali E, McGrath MT, Hu J, Crosby K, Miller SA. Phytophthora capsici, 100 Years Later: Research Mile Markers from 1922 to 2022. PHYTOPATHOLOGY 2023; 113:921-930. [PMID: 36401843 DOI: 10.1094/phyto-08-22-0297-rvw] [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] [Indexed: 06/16/2023]
Abstract
In 1922, Phytophthora capsici was described by Leon Hatching Leonian as a new pathogen infecting pepper (Capsicum annuum), with disease symptoms of root rot, stem and fruit blight, seed rot, and plant wilting and death. Extensive research has been conducted on P. capsici over the last 100 years. This review succinctly describes the salient mile markers of research on P. capsici with current perspectives on the pathogen's distribution, economic importance, epidemiology, genetics and genomics, fungicide resistance, host susceptibility, pathogenicity mechanisms, and management.
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Affiliation(s)
- Soum Sanogo
- Department of Entomology, Plant Pathology, and Weed Science, New Mexico State University, Las Cruces, NM 88003
| | - Kurt Lamour
- Department of Entomology and Plant Pathology, The University of Tennessee Institute of Agriculture, Knoxville, TN 37996
| | - Chandrasekar S Kousik
- U.S. Vegetable Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Charleston, SC 29414
| | - Dennis N Lozada
- Department of Plant and Environmental Sciences and Chile Pepper Institute, New Mexico State University, Las Cruces, NM 88003
| | - Camilo H Parada-Rojas
- Department of Entomology and Plant Pathology, NC Plant Sciences Initiative, North Carolina State University, Raleigh, NC 27695
| | - Lina M Quesada-Ocampo
- Department of Entomology and Plant Pathology, NC Plant Sciences Initiative, North Carolina State University, Raleigh, NC 27695
| | - Christian A Wyenandt
- Department of Plant Biology, Rutgers University, Rutgers Agricultural Research and Extension Center, Bridgeton, NJ 08302
| | | | - Mary K Hausbeck
- Department of Soil, Plant, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Zachariah Hansen
- Department of Entomology and Plant Pathology, The University of Tennessee Institute of Agriculture, Knoxville, TN 37996
| | - Emran Ali
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH 03824
| | - Margaret T McGrath
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Long Island Horticultural Research and Extension Center, Riverhead, NY 11901
| | - Jiahuai Hu
- School of Plant Sciences, The University of Arizona, Tucson, AZ 85721
| | - Kevin Crosby
- Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843
| | - Sally A Miller
- Department of Plant Pathology, The Ohio State University, Wooster, OH 44691
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Ma M, Taylor PWJ, Chen D, Vaghefi N, He JZ. Major Soilborne Pathogens of Field Processing Tomatoes and Management Strategies. Microorganisms 2023; 11:microorganisms11020263. [PMID: 36838227 PMCID: PMC9958975 DOI: 10.3390/microorganisms11020263] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/28/2022] [Accepted: 12/28/2022] [Indexed: 01/20/2023] Open
Abstract
Globally, tomato is the second most cultivated vegetable crop next to potato, preferentially grown in temperate climates. Processing tomatoes are generally produced in field conditions, in which soilborne pathogens have serious impacts on tomato yield and quality by causing diseases of the tomato root system. Major processing tomato-producing countries have documented soilborne diseases caused by a variety of pathogens including bacteria, fungi, nematodes, and oomycetes, which are of economic importance and may threaten food security. Recent field surveys in the Australian processing tomato industry showed that plant growth and yield were significantly affected by soilborne pathogens, especially Fusarium oxysporum and Pythium species. Globally, different management methods have been used to control diseases such as the use of resistant tomato cultivars, the application of fungicides, and biological control. Among these methods, biocontrol has received increasing attention due to its high efficiency, target-specificity, sustainability and public acceptance. The application of biocontrol is a mix of different strategies, such as applying antagonistic microorganisms to the field, and using the beneficial metabolites synthesized by these microorganisms. This review provides a broad review of the major soilborne fungal/oomycete pathogens of the field processing tomato industry affecting major global producers, the traditional and biological management practices for the control of the pathogens, and the various strategies of the biological control for tomato soilborne diseases. The advantages and disadvantages of the management strategies are discussed, and highlighted is the importance of biological control in managing the diseases in field processing tomatoes under the pressure of global climate change.
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Han L, Liu Y, Nie J, You X, Li Y, Wang X, Wang J. Indigenous functional microbial degradation of the chiral fungicide mandipropamid in repeatedly treated soils: Preferential changes in the R-enantiomer. JOURNAL OF HAZARDOUS MATERIALS 2022; 435:128961. [PMID: 35472545 DOI: 10.1016/j.jhazmat.2022.128961] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/15/2022] [Accepted: 04/16/2022] [Indexed: 06/14/2023]
Abstract
This study investigated the indigenous functional microbial communities associated with the degradation of chiral fungicide mandipropamid enantiomers in soils repeatedly treated with a single enantiomer. The R-enantiomer degraded faster than the S-enantiomer, with degradation half-lives ranging from 10.2 d to 79.2 d for the R-enantiomer and 10.4 d to 130.5 d for the S-enantiomer. Six bacterial genera, (Burkholderia, Paraburkholderia, Hyphomicrobium, Methylobacterium, Caballeronia, and Ralstonia) with R-enantiomer substrate preference and three bacterial genera (Haliangium, Sorangium, and Sandaracinus) with S-enantiomer substate preference were responsible for the preferential degradation of the R-enantiomer and S-enantiomer, respectively. KEGG analysis indicated that Burkholderia, Paraburkholderia, Hyphomicrobium, and Methylobacterium were the dominant contributors to soil microbial metabolic functions. Notably, six microbial metabolic pathways and twelve functional enzyme genes were associated with the preferential degradation of the R-enantiomer, whose relative abundances in the R-enantiomer treatment were higher than those in the S-enantiomer treatment. A constructed biodegradation gene (BDG) protein database analysis further confirmed that Burkholderia, Paraburkholderia, Hyphomicrobium, Methylobacterium, and Ralstonia were the potential hosts of five dominant BDGs, bphA1, benA, bph, p450, and ppah. We concluded that bacterial genera Burkholderia, Paraburkholderia, Hyphomicrobium, and Methylobacterium may play pivotal roles in the preferential degradation of mandipropamid R-enantiomer in repeatedly treated soils.
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Affiliation(s)
- Lingxi Han
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences (CAAS), Qingdao 266101, PR China; College of Horticulture, Qingdao Agricultural University/Laboratory of Quality & Safety Risk Assessment for Fruit (Qingdao), Ministry of Agriculture and Rural Affairs/National Technology Centre for Whole Process Quality Control of FSEN Horticultural Products (Qingdao)/Qingdao Key Lab of Modern Agriculture Quality and Safety Engineering, Qingdao 266109, China
| | - Yalei Liu
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences (CAAS), Qingdao 266101, PR China
| | - Jiyun Nie
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences (CAAS), Qingdao 266101, PR China; College of Horticulture, Qingdao Agricultural University/Laboratory of Quality & Safety Risk Assessment for Fruit (Qingdao), Ministry of Agriculture and Rural Affairs/National Technology Centre for Whole Process Quality Control of FSEN Horticultural Products (Qingdao)/Qingdao Key Lab of Modern Agriculture Quality and Safety Engineering, Qingdao 266109, China
| | - Xiangwei You
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences (CAAS), Qingdao 266101, PR China
| | - Yiqiang Li
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences (CAAS), Qingdao 266101, PR China
| | - Xiuguo Wang
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences (CAAS), Qingdao 266101, PR China.
| | - Jun Wang
- College of Resources and Environment, Key Laboratory of Agricultural Environment, Shandong Agricultural University, Tai'an 271000, PR China
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Cheng W, Lin M, Chu M, Xiang G, Guo J, Jiang Y, Guan D, He S. RNAi-Based Gene Silencing of RXLR Effectors Protects Plants Against the Oomycete Pathogen Phytophthora capsici. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:440-449. [PMID: 35196108 DOI: 10.1094/mpmi-12-21-0295-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Phytophthora capsici is a broad-host range oomycete pathogen that can cause severe phytophthora blight disease of pepper and hundreds of other plant species worldwide. Natural resistance against P. capsici is inadequate, and it is very difficult to control by most of existing chemical fungicides. Therefore, it is urgent to develop alternative strategies to control this pathogen. Recently, host-induced or spray-induced gene silencing of essential or virulent pathogen genes provided an effective strategy for disease controls. Here, we demonstrate that P. capsici can effectively take up small interfering RNAs (siRNAs) from the environment. According to RNA-seq and quantitative reverse transcription PCR analysis, we identified four P. capsici RXLR effector genes that are significantly up-regulated during the infection stage. Transient overexpression and promote-infection assays indicated that RXLR1 and RXLR4 could promote pathogen infection. Using a virus-induced gene silencing system in pepper plants, we found that in planta-expressing RNA interference (RNAi) constructs that target RXLR1 or RXLR4 could significantly reduce pathogen infection, while co-interfering RXLR1 and RXLR4 could confer a more enhanced resistance to P. capsici. We also found that exogenously applying siRNAs that target RXLR1 or RXLR4 could restrict growth of P. capsici on the pepper and Nicotiana benthamiana leaves; when targeting RXLR1 and RXLR4 simultaneously, the control effect was more remarkable. These data suggested that RNAi-based gene silencing of RXLR effectors has great potential for application in crop improvement against P. capsici and also provides an important basis for the development of RNA-based antioomycete agents.[Formula: see text] Copyright © 2022 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)
- Wei Cheng
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources/College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
- National Education Minister Key Laboratory of Plant Genetic Improvement and Comprehensive Utilization/College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Menglan Lin
- National Education Minister Key Laboratory of Plant Genetic Improvement and Comprehensive Utilization/College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Moli Chu
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources/College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Guixiang Xiang
- National Education Minister Key Laboratory of Plant Genetic Improvement and Comprehensive Utilization/College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Jianwen Guo
- National Education Minister Key Laboratory of Plant Genetic Improvement and Comprehensive Utilization/College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Yan Jiang
- National Education Minister Key Laboratory of Plant Genetic Improvement and Comprehensive Utilization/College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Deyi Guan
- National Education Minister Key Laboratory of Plant Genetic Improvement and Comprehensive Utilization/College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Shuilin He
- National Education Minister Key Laboratory of Plant Genetic Improvement and Comprehensive Utilization/College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
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Kousik CS, Ikerd JL, Wechter WP, Branham S, Turechek W. Broad Resistance to Post-Harvest Fruit Rot in USVL Watermelon Germplasm Lines to Isolates of Phytophthora capsici Across the United States. PLANT DISEASE 2022; 106:711-719. [PMID: 34579551 DOI: 10.1094/pdis-11-20-2480-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: 06/13/2023]
Abstract
Watermelon is an important cucurbit vegetable crop grown in most of the United States. Phytophthora fruit rot of watermelon caused by Phytophthora capsici has been a major factor, limiting production for the past 15 years in the southeastern United States. The U.S. Department of Agriculture, Agricultural Research Service released five Phytophthora fruit rot-resistant germplasm lines for use in breeding programs. These lines were developed by phenotyping using a local isolate of P. capsici from South Carolina. The present study was undertaken to determine if these resistant lines had broad resistance to diverse P. capsici isolates collected from different states and crops. Five resistant germplasm lines (USVL020-PFR, USVL203-PFR, USVL782-PFR, USVL489-PFR, and USVL531-MDR) and two susceptible cultivars, Sugar Baby and Mickey Lee, used as checks were grown in a field in 2014 and 2015 to produce fruit for evaluation. Mature fruit were harvested and placed in a walk-in growth chamber and inoculated with 20 different P. capsici isolates. The chamber was maintained at 26 ± 2°C and high relative humidity (>95%) using a humidifier. All five resistant germplasm lines were significantly more resistant than the two susceptible checks to all 20 P. capsici isolates. Among the five resistant germplasm lines, USVL020-PFR, USVL782-PFR, and USVL531-MDR had broad resistance. Some P. capsici isolates induced minor lesions and rot on USVL489-PFR compared with the other resistant lines. Variation in virulence and genetic diversity among the 20 P. capsici isolates was also observed. The five watermelon germplasm lines will be useful for developing commercial watermelon cultivars with broad resistance to P. capsici.
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Affiliation(s)
- Chandrasekar S Kousik
- U.S. Vegetable Laboratory, U.S. Department of Agriculture Agricultural Research Service, Charleston, SC 29414
| | - Jennifer L Ikerd
- U.S. Vegetable Laboratory, U.S. Department of Agriculture Agricultural Research Service, Charleston, SC 29414
| | - W Patrick Wechter
- U.S. Vegetable Laboratory, U.S. Department of Agriculture Agricultural Research Service, Charleston, SC 29414
| | - Sandra Branham
- Coastal Research and Education Center, Clemson University, Charleston, SC 29414
| | - William Turechek
- U.S. Horticultural Research Laboratory, U.S. Department of Agriculture Agricultural Research Service, Fort Pierce, FL 34945
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Zhang J, Wu Q, Zhong Y, Wang Z, He Z, Zhang Y, Wang M. Enantioselective Bioactivity, Toxicity, and Degradation in Vegetables and Soil of Chiral Fungicide Mandipropamid. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:13416-13424. [PMID: 34738463 DOI: 10.1021/acs.jafc.1c04370] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mandipropamid (MDP) is a widely used chiral fungicide to control oomycete pathogens with two enantiomers. In this study, the enantioselective bioactivity, toxicity, and degradation of MDP were investigated for the first time. The bioactivity of S-MDP was 118-592 times higher than that of R-MDP and 1.14-1.67 times higher than that of Rac-MDP against six phytopathogens. Molecular docking found that S-MDP formed a strong halogen bond with HIS 693 of cellulose synthase and possessed a lower binding energy, which validated the results of the bioactivity assay. S-MDP showed lower toxicity toward Spirodela polyrhiza, while it exhibited higher toxicity in Danio rerio embryo and larva. S-MDP preferentially degraded in cowpea and pepper, while R-MDP preferentially degraded in soil. There is no significant difference between the two enantiomers in the toxicity of adult D. rerio and in cucumber degradation. Therefore, the development of the S-enantiomer was considered as a better option to exhibit high efficiency, which could reduce the residual risk of the pesticide and ensure environmental safety.
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Affiliation(s)
- Jing Zhang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
| | - Qiqi Wu
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
| | - Yanru Zhong
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
| | - Zhen Wang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
| | - Zongzhe He
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
| | - Yanqing Zhang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
| | - Minghua Wang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China
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Siegenthaler TB, Hansen ZR. Sensitivity of Phytophthora capsici from Tennessee to Mefenoxam, Fluopicolide, Oxathiapiprolin, Dimethomorph, Mandipropamid, and Cyazofamid. PLANT DISEASE 2021; 105:3000-3007. [PMID: 33736467 DOI: 10.1094/pdis-08-20-1805-re] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Phytophthora blight is a destructive disease caused by the oomycete Phytophthora capsici, which affects vegetable production throughout the state of Tennessee and worldwide. Fungicides are a primary control method used in managing Phytophthora blight, but in some cases the efficacy of these products has been reduced or lost in the field. In 2018 and 2019, the efficacy of six fungicides was tested in vitro on 184 P. capsici isolates collected in Tennessee using radial growth assays. The fungicides included in the study were mefenoxam, fluopicolide, oxathiapiprolin, dimethomorph, mandipropamid, and cyazofamid. Seven isolates were resistant to mefenoxam, 86 were resistant to fluopicolide, one was resistant to oxathiapiprolin, and 13 were resistant to cyazofamid. None were resistant to dimethomorph or mandipropamid. Of the 86 isolates resistant to fluopicolide, five were also resistant to mefenoxam. Resistance to fluopicolide and cyazofamid was widespread in Tennessee, and it was more localized for mefenoxam and oxathiapiprolin. The results of this study show that fungicide resistance is widespread in P. capsici in Tennessee, and the implications for Phytophthora blight management are discussed.
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Affiliation(s)
| | - Zachariah R Hansen
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN
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Wang L, Ji P. Fitness and Competitive Ability of Field Isolates of Phytophthora capsici Resistant or Sensitive to Fluopicolide. PLANT DISEASE 2021; 105:873-878. [PMID: 33151816 DOI: 10.1094/pdis-08-20-1729-re] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Phytophthora blight, caused by Phytophthora capsici, is one of the most destructive diseases in the production of solanaceous and cucurbitaceous vegetable crops. Fluopicolide has been used to control the disease; however, reduced efficacy of the fungicide was observed in Georgia. P. capsici isolates were collected from commercial vegetable fields in Georgia in 2018 and 2019 to determine sensitivity to fluopicolide, which were phenotyped to have 43.1% of the isolates as resistant. The fitness of resistant (R) and sensitive (S) isolates was assessed through mycelial growth and sporulation assays exposed to the fungicide (0 or 50 µg/ml). Fluopicolide did not reduce mycelial growth, sporangial production, and zoospore germination of the R isolates. In the absence of fluopicolide, there was no significant difference between the R and S isolates in sporangial production but mycelial growth and zoospore germination of the R isolates was greater than the S isolates (P = 0.01 and 0.001, respectively). The R isolates had an ability similar to that of the S isolates to induce disease on Aristotle bell pepper, and most of the R and S isolates caused the same level of disease on Paladin. Inoculating squash fruit using different R:S ratios and recovering R and S isolates after five cycles of inoculation resulted in similar trends in changes of R versus S isolate ratios. Overall, it appeared that fitness and competitive ability of the R isolates were not reduced compared with the S isolates. This is the first report of the occurrence of field isolates of P. capsici resistant to fluopicolide in the world. The results have significant implications in providing guidance for growers to avoid or limit use of this fungicide in vegetable production.
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Affiliation(s)
- Li Wang
- Department of Plant Pathology, University of Georgia, Tifton, GA 31793
| | - Pingsheng Ji
- Department of Plant Pathology, University of Georgia, Tifton, GA 31793
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Vogel G, LaPlant KE, Mazourek M, Gore MA, Smart CD. A combined BSA-Seq and linkage mapping approach identifies genomic regions associated with Phytophthora root and crown rot resistance in squash. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2021; 134:1015-1031. [PMID: 33388885 DOI: 10.1007/s00122-020-03747-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/05/2020] [Indexed: 06/12/2023]
Abstract
Two QTL mapping approaches were used to identify a total of six QTL associated with Phytophthora root and crown rot resistance in a biparental squash population. Phytophthora root and crown rot, caused by the soilborne oomycete pathogen Phytophthora capsici, leads to severe yield losses in squash (Cucurbita pepo). To identify quantitative trait loci (QTL) involved in resistance to this disease, we crossed a partially resistant squash breeding line with a susceptible zucchini cultivar and evaluated over 13,000 F2 seedlings in a greenhouse screen. Bulked segregant analysis with whole genome resequencing (BSA-Seq) resulted in the identification of five genomic regions-on chromosomes 4, 5, 8, 12, and 16-featuring significant allele frequency differentiation between susceptible and resistant bulks in each of two independent replicates. In addition, we conducted linkage mapping using a population of 176 F3 families derived from individually genotyped F2 individuals. Variation in disease severity among these families was best explained by a four-QTL model, comprising the same loci identified via BSA-Seq on chromosomes 4, 5, and 8 as well as an additional locus on chromosome 19, for a combined total of six QTL identified between both methods. Loci, whether those identified by BSA-Seq or linkage mapping, were of small-to-moderate effect, collectively accounting for 28-35% and individually for 2-10% of the phenotypic variance explained. However, a multiple linear regression model using one marker in each BSA-Seq QTL could predict F2:3 disease severity with only a slight drop in cross-validation accuracy compared to genomic prediction models using genome-wide markers. These results suggest that marker-assisted selection could be a suitable approach for improving Phytophthora crown and root rot resistance in squash.
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Affiliation(s)
- Gregory Vogel
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY, 14456, USA
| | - Kyle E LaPlant
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Michael Mazourek
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Michael A Gore
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Christine D Smart
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY, 14456, USA.
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Retes-Manjarrez JE, Rubio-Aragón WA, Márques-Zequera I, Cruz-Lachica I, García-Estrada RS, Sy O. Novel Sources of Resistance to Phytophthora capsici on Pepper ( Capsicum sp.) Landraces from Mexico. THE PLANT PATHOLOGY JOURNAL 2020; 36:600-607. [PMID: 33312095 PMCID: PMC7721533 DOI: 10.5423/ppj.oa.07.2020.0131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/29/2020] [Accepted: 11/02/2020] [Indexed: 06/12/2023]
Abstract
Phytophthora capsici Leonian is a major pathogen of pepper worldwide and few resistance sources to this pathogen have been identified so far. The goals of this study were to identify new sources of resistance against P. capsici in Capsicum landraces and analyze the relationship between the resistance indicator of plant symptoms and some plant phenotype parameters of plant height, stem width, leaf length and leaf width. Thirtytwo landraces of pepper were collected from fourteen states in Mexico. From each population, 36 plants were inoculated with 10,000 zoospores of P. capsici under controlled conditions. This experiment was repeated twice. Out of the 32 landraces, six showed high level of resistance, four showed intermediate resistance and five showed low level of resistance when compared with the susceptible control 'Bravo' and the resistant control 'CM334', indicating that these landraces are promising novel sources of resistance to P. capsici. There was no correlation between the symptoms and plant phenotype parameters. However, these parameters were not affected in the group classified as highly resistant, indicating that P. capsici does not affect the growing of these resistant pepper landraces. The other resistant groups were significantly affected in a differently manner regarding their phenotype, indicating that this pathogen reduce their growth in different ways. This study reports novel resistance sources with great potential that could be used in breeding programs to develop new pepper cultivars with durable resistance to P. capsici.
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Affiliation(s)
- Jesús Enrique Retes-Manjarrez
- Facultad de Agronomía, Universidad Autónoma de Sinaloa, Carretera Culiacán-Eldorado, km 7.5, C.P. 80000, Culiacán, Sinaloa, México
- Wholesum, Carretera Hermosillo-Nogales, km 16, C.P. 84134, Colonia Los Janos, Imuris Sonora, México
| | - Walter Arturo Rubio-Aragón
- Facultad de Agronomía, Universidad Autónoma de Sinaloa, Carretera Culiacán-Eldorado, km 7.5, C.P. 80000, Culiacán, Sinaloa, México
| | - Isidro Márques-Zequera
- Centro de Investigación en Alimentación y Desarrollo, A. C. Carretera Culiacán-El Dorado, km 5.5, Culiacán Sinaloa, México
| | - Isabel Cruz-Lachica
- Centro de Investigación en Alimentación y Desarrollo, A. C. Carretera Culiacán-El Dorado, km 5.5, Culiacán Sinaloa, México
| | - Raymundo Saúl García-Estrada
- Centro de Investigación en Alimentación y Desarrollo, A. C. Carretera Culiacán-El Dorado, km 5.5, Culiacán Sinaloa, México
| | - Ousmane Sy
- Independent Researcher, Dakar, Senegal, C.P. 10200, México
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Wu Q, Zhao B, Fan Z, Guo X, Yang D, Zhang N, Yu B, Zhou S, Zhao J, Chen F. Discovery of Novel Piperidinylthiazole Derivatives As Broad-Spectrum Fungicidal Candidates. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:1360-1370. [PMID: 30640452 DOI: 10.1021/acs.jafc.8b06054] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Oxathiapiprolin is one of the best active fungicides discovered for oomycetes control. To develop a fungicide candidate with a broad spectrum of activity, 22 new piperidinylthiazole derivatives were designed and synthesized. Compound 5l showed the best activity against Pseudoperonospora cubensis (Berk. et Curt.) Rostov and Phytophthora infestans in vivo with 100% and 80% of inhibition, respectively, at 1 mg/L, and 72.87% of field efficacy against P. cubensis at 1 g ai/667 m2 validated these results. Compound 5i exhibited a broad spectrum of excellent activity against Sclerotinia sclerotiorum with EC50 = 0.30 mg/L (>10 times more active than oxathiapiprolin and azoxystrobin in vitro), good activity against Botrytis cinerea, Cercospora arachidicola, and Gibberella zeae with EC50 of 14.54, 5.57, and 14.03 mg/L in vitro and against P. cubensis and P. infestans with 60% and 30% inhibition rates, respectively, at 1 mg/L in vivo. Mode of action studies by RNA sequencing analysis discovered oxysterol-binding protein (OSBP), chitin synthase (CHS1), and (1,3)-β-glucan synthase (FKS2) as the potent target of 5i against S. sclerotiorum. Quenching studies validated that OSBP was the same target of both 5i and oxathiapiprolin; it was quenched by both of them. Our studies discovered isothiazole-containing piperidinylthiazole as an OSBP target-based novel lead for fungicide development.
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Affiliation(s)
- Qifan Wu
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Bin Zhao
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Zhijin Fan
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Nankai University , Tianjin 300071 , P. R. China
| | - Xiaofeng Guo
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Dongyan Yang
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Nailou Zhang
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Bin Yu
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Shuang Zhou
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Jiabao Zhao
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
| | - Fan Chen
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , P. R. China
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Hao K, Lin B, Nian F, Gao X, Wei Z, Luo G, Lu Y, Lan M, Yang J, Wu G. RNA-seq analysis of the response of plant-pathogenic oomycete Phytophthora parasitica to the fungicide dimethomorph. Rev Argent Microbiol 2019; 51:268-277. [PMID: 30670299 DOI: 10.1016/j.ram.2018.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/31/2018] [Accepted: 08/26/2018] [Indexed: 10/27/2022] Open
Abstract
Phytophthora parasitica is an important oomycete that causes disease in a variety of plants, dimethomorph fungicides being specific for oomycetes. The aim of this study was to use RNA-seq to rapidly discover the mechanism by which dimethomorph acts in the treatment of P. parasitica. We found that the expression of 832 genes changed significantly after the dimethomorph treatment, including 365 up-regulated genes and 467 down-regulated genes. According to the Gene Ontology (GO) enrichment analysis, pathway enrichment and verification test results, the following conclusions are obtained: (i) the treatment of P. parasitica with dimethomorph causes changes in the expression levels of genes associated with the cell wall and cell wall synthesis; (ii) dimethomorph treatment results in reduced permeability of the cell membrane and changes in the expression of certain transport-related proteins; (iii) dimethomorph treatment increased reactive oxygen species and reduced the expression of genes related to the control of oxidative stress.
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Affiliation(s)
- Kaiqiang Hao
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China; Tobacco Research Institute of the Chinese Academy of Agricultural Sciences, Qingdao, Shandong 266101, China
| | - Beisen Lin
- Tobacco Science Research Institute of Baise Tobacco Company, Baise, Guangxi 533000, China; Hainan Provincial Branch of China National Tobacco Corporation, Haikou, Hainan, 571100, China
| | - Fuzhao Nian
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China
| | - Xi Gao
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China
| | - Zhong Wei
- Tobacco Science Research Institute of Baise Tobacco Company, Baise, Guangxi 533000, China
| | - Gang Luo
- Tobacco Science Research Institute of Baise Tobacco Company, Baise, Guangxi 533000, China
| | - Yachun Lu
- Tobacco Science Research Institute of Baise Tobacco Company, Baise, Guangxi 533000, China
| | - Mingxian Lan
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China
| | - Jinguang Yang
- Tobacco Research Institute of the Chinese Academy of Agricultural Sciences, Qingdao, Shandong 266101, China.
| | - Guoxing Wu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming 650201, China.
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16
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Lawal A, Wong RCS, Tan GH, Abdulra'uf LB, Alsharif AMA. Recent Modifications and Validation of QuEChERS-dSPE Coupled to LC-MS and GC-MS Instruments for Determination of Pesticide/Agrochemical Residues in Fruits and Vegetables: Review. J Chromatogr Sci 2018; 56:656-669. [PMID: 29688338 DOI: 10.1093/chromsci/bmy032] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Indexed: 02/03/2023]
Abstract
Fruits and vegetables constitute a major type of food consumed daily apart from whole grains. Unfortunately, the residual deposits of pesticides in these products are becoming a major health concern for human consumption. Consequently, the outcome of the long-term accumulation of pesticide residues has posed many health issues to both humans and animals in the environment. However, the residues have previously been determined using conventionally known techniques, which include liquid-liquid extraction, solid-phase extraction (SPE) and the recently used liquid-phase microextraction techniques. Despite the positive technological effects of these methods, their limitations include; time-consuming, operational difficulty, use of toxic organic solvents, low selective property and expensive extraction setups, with shorter lifespan of instrumental performances. Thus, the potential and maximum use of these methods for pesticides residue determination has resulted in the urgent need for better techniques that will overcome the highlighted drawbacks. Alternatively, attention has been drawn recently towards the use of quick, easy, cheap, effective, rugged and safe technique (QuEChERS) coupled with dispersive solid-phase extraction (dSPE) to overcome the setback challenges experienced by the previous technologies. Conclusively, the reviewed QuEChERS-dSPE techniques and the recent cleanup modifications justifiably prove to be reliable for routine determination and monitoring the concentration levels of pesticide residues using advanced instruments such as high-performance liquid chromatography, liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry.
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Affiliation(s)
- Abubakar Lawal
- Department of Chemistry, University of Malaya, Kuala Lumpur, Malaysia.,Department of Pure and Industrial Chemistry, Umaru Musa Yar'adua University, P.M.B. Katsina, Nigeria
| | | | - Guan Huat Tan
- Department of Chemistry, University of Malaya, Kuala Lumpur, Malaysia
| | - Lukman Bola Abdulra'uf
- Department of Chemistry, College of Pure and Applied Sciences, Kwara State University Malete, P.M.B. Ilorin, Nigeria
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Kousik CS, Ikerd JL, Turechek WW. Development of Phytophthora Fruit Rot Caused by Phytophthora capsici on Resistant and Susceptible Watermelon Fruit of Different Ages. PLANT DISEASE 2018; 102:370-374. [PMID: 30673515 DOI: 10.1094/pdis-06-17-0898-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Watermelon is an important crop grown in 44 states in the United States. Phytophthora fruit rot caused by Phytophthora capsici is a serious disease in the southeastern U.S.A., where over 50% of the watermelons are produced. The disease has resulted in severe losses to watermelon growers, especially in Georgia, South Carolina, and North Carolina during the past few years. Several fruit rot-resistant watermelon germplasm lines have been developed for use in breeding programs. To evaluate the development of Phytophthora fruit rot on fruit of different ages, plants of fruit rot-resistant and susceptible lines were planted at weekly intervals for five consecutive weeks in experiments conducted over three years (2011 to 2013). Flowers were routinely inspected and hand pollinated to ensure having fruit of different ages. In each year, different aged fruit were harvested on the same day and inoculated with a 5-mm agar plug from an actively growing colony of P. capsici. Inoculated fruit were maintained in a room set to conditions conducive for disease development (>95% relative humidity, 26 ± 2°C). After 5 days, lesion diameter and intensity of sporulation was recorded for each fruit. Lesion diameter and sporulation intensity were significantly greater on fruit of susceptible lines compared with resistant lines. Fruit age did not have an effect on either measurement on susceptible (Sugar Baby) or resistant lines (PI 560020 and PI 595203). Our results showed that resistance to Phytophthora fruit rot in watermelon was not correlated with fruit age.
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Affiliation(s)
- Chandrasekar S Kousik
- United States Department of Agriculture, Agricultural Research Service, U.S. Vegetable Laboratory, 2700 Savannah Highway, Charleston, SC 29414
| | - Jennifer L Ikerd
- United States Department of Agriculture, Agricultural Research Service, U.S. Vegetable Laboratory, 2700 Savannah Highway, Charleston, SC 29414
| | - William W Turechek
- United States Department of Agriculture, Agricultural Research Service, U.S. Horticultural Research Laboratory, Fort Pierce, FL 34945
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18
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Pánek M, Tomšovský M. In vitro growth response of Phytophthora cactorum, P. nicotianae and P. × pelgrandis to antibiotics and fungicides. Folia Microbiol (Praha) 2017; 62:269-277. [PMID: 28127667 DOI: 10.1007/s12223-017-0493-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 01/12/2017] [Indexed: 11/26/2022]
Abstract
The reactions of isolates of Phytophthora cactorum, P. nicotianae and P. × pelgrandis to metalaxyl, mancozeb, dimethomorph, streptomycin and chloramphenicol were tested to obtain information about the variability of resistance in these pathogens. Distinct genetic groups showed significant differences in resistance to all tested substances except streptomycin. In response to streptomycin, the growth inhibition rates of distinct groups did not differ significantly. The most remarkable differences were detected in the reactions to chloramphenicol and metalaxyl. Discriminant analysis evaluating the effect of all substances confirmed the differences among the groups, which are in agreement with the differences revealed by earlier DNA analyses.
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Affiliation(s)
- M Pánek
- Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00, Brno, Czech Republic.
- Crop Research Institute, Drnovská 507/73, 161 06, Praha 6, Czech Republic.
| | - M Tomšovský
- Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00, Brno, Czech Republic
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Petkar A, Langston DB, Buck JW, Stevenson KL, Ji P. Sensitivity of Fusarium oxysporum f. sp. niveum to Prothioconazole and Thiophanate-Methyl and Gene Mutation Conferring Resistance to Thiophanate-Methyl. PLANT DISEASE 2017; 101:366-371. [PMID: 30681924 DOI: 10.1094/pdis-09-16-1236-re] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Fusarium wilt, incited by the fungus Fusarium oxysporum f. sp. niveum, is a soilborne disease that affects watermelon production worldwide. Approaches for effective management of Fusarium wilt in watermelon are limited. Studies conducted in recent years indicated that prothioconazole and thiophanate-methyl reduced the disease significantly under field conditions. However, effects of the fungicides on different life stages of F. oxysporum f. sp. niveum and potential existence of fungicide resistance in F. oxysporum f. sp. niveum populations are unknown. In the present study, effects of prothioconazole and thiophanate-methyl on mycelium growth and spore germination of F. oxysporum f. sp. niveum isolates collected in watermelon fields in Georgia were determined. In vitro mycelium growth studies indicated that all 100 isolates evaluated were sensitive to prothioconazole; the effective concentration that suppressed mycelium growth by 50% ranged from 0.75 to 5.69 μg/ml (averaged 1.62 μg/ml). In contrast, 33 and 4% of the isolates were resistant to thiophanate-methyl at 10 and 100 μg/ml, respectively. Microconidial germination assays showed that 36 and 64% of the isolates tested were sensitive or intermediately sensitive to prothioconazole at 100 μg/ml but the fungicide did not inhibit spore germination at 10 μg/ml. Sequencing a portion of the β-tubulin gene of eight isolates resistant or sensitive to thiophanate-methyl indicated that fungicide resistance was associated with a point mutation at nucleotide position 200, resulting in a substitution of phenylalanine by tyrosine. This is the first report of isolates of F. oxysporum resistant to thiophanate-methyl. Results of the research suggest that prothioconazole may be a viable option for management of Fusarium wilt of watermelon whereas thiophanate-methyl should be used judiciously due to the existence of isolates resistant to the fungicide.
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Affiliation(s)
- Aparna Petkar
- Department of Plant Pathology, University of Georgia, Tifton 31794
| | - David B Langston
- Tidewater Agricultural Research and Extension Center, Virginia Tech, Suffolk 23437
| | - James W Buck
- Department of Plant Pathology, University of Georgia, Griffin 30223
| | | | - Pingsheng Ji
- Department of Plant Pathology, University of Georgia, Tifton
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20
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Qu T, Grey TL, Csinos AS, Ji P. Translocation of Oxathiapiprolin in Bell Pepper Plants and Systemic Protection of Plants Against Phytophthora Blight. PLANT DISEASE 2016; 100:1931-1936. [PMID: 30682987 DOI: 10.1094/pdis-03-16-0370-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Production of bell pepper is seriously affected by Phytophthora capsici, the causal agent of Phytophthora blight. Limited approaches are available for effective management of the disease. Oxathiapiprolin is a fungicide recently registered in the United States that suppressed P. capsici and reduced Phytophthora blight on bell pepper significantly in our previous studies. It is unknown whether oxathiapiprolin translocates in bell pepper plants systemically after application. Experiments were conducted to determine uptake of oxathiapiprolin by bell pepper plants and its systemic movement in the plant. Quantification of oxathiapiprolin in plant tissues was conducted by high-performance liquid chromatography (HPLC) that detected the compound sensitively and selectively. Percentage of recovery of oxathiapiprolin from plant tissues was calculated by comparing the quantities in plant tissues determined by HPLC with known quantities of the compound added to the plant tissues. Recovery rates of oxathiapiprolin from pepper plant tissues ranged from 87.0 to 119.3%. When oxathiapiprolin was applied to roots of bell pepper plants grown in hydroculture, the compound was detected in the root within 4 h and in the cotyledon, first true leaf, and second true leaf within 8 h. It was detectable in the top new leaf 48 h after application to the root. In greenhouse studies with bell pepper plants grown in pots, oxathiapiprolin was applied as a soil drench at 100 and 400 μg/ml. The compound was detected in the root within 3 days and in the stem and first true leaf within 6 days when applied at 100 μg/ml. It was detected in the root, stem, first true leaf, and top new leaf within 3 days when applied at 400 μg/ml. Phytophthora blight on pepper foliage was significantly reduced when oxathiapiprolin was applied as a soil drench at 100 or 400 μg/ml under greenhouse conditions. This is the first report indicating systemic movement of oxathiapiprolin in pepper plants that provides useful information for designing fungicide application programs for effective management of the disease.
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Affiliation(s)
- Tianli Qu
- Chemistry and Pharmacy College, Qingdao Agricultural University, Shandong 266109, China; and Department of Plant Pathology, University of Georgia, Tifton 31794
| | - Timothy L Grey
- Department of Crop and Soil Sciences, University of Georgia
| | | | - Pingsheng Ji
- Department of Plant Pathology, University of Georgia, Tifton 31794
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Liu P, Gong J, Ding X, Jiang Y, Chen G, Li B, Weng Q, Chen Q. The L-type Ca(2+) Channel Blocker Nifedipine Inhibits Mycelial Growth, Sporulation, and Virulence of Phytophthora capsici. Front Microbiol 2016; 7:1236. [PMID: 27540377 PMCID: PMC4972815 DOI: 10.3389/fmicb.2016.01236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 07/25/2016] [Indexed: 11/19/2022] Open
Abstract
The oomycete vegetable pathogen Phytophthora capsici causes significant losses of important vegetable crops worldwide. Calcium and other plant nutrients have been used in disease management of oomycete pathogens. Calcium homeostasis and signaling is essential for numerous biological processes, and Ca(2+) channel blockers prevent excessive Ca(2+) influx into the fungal cell. However, it is not known whether voltage-gated Ca(2+) channel blockers improve control over oomycete pathogens. In the present study, we compared the inhibitory effects of CaCl2 and the extracellular Ca(2+) chelator EDTA on mycelial growth and found that calcium assimilation plays a key role in P. capsici mycelial growth. Next, we involved the voltage-gated Ca(2+) channel blockers verapamil (VP) and nifedipine (NFD) to analyze the effect of Ca(2+) channel blockers on mycelial growth and sporulation; the results suggested that NFD, but not VP, caused significant inhibition. Ion rescue in an NFD-induced inhibition assay suggested that NFD-induced inhibition is calcium-dependent. In addition, NFD increased P. capsici sensitivity to H2O2 in a calcium-dependent manner, and extracellular calcium rescued it. Furthermore, NFD inhibited the virulence and gene expression related to its pathogenicity. These results suggest that NFD inhibits mycelial growth, sporulation, and virulence of P. capsici.
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Affiliation(s)
| | | | | | | | | | | | - Qiyong Weng
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural SciencesFuzhou, China
| | - Qinghe Chen
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural SciencesFuzhou, China
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Patel JS, Vitoreli A, Palmateer AJ, El-Sayed A, Norman DJ, Goss EM, Brennan MS, Ali GS. Characterization of Phytophthora spp. Isolated from Ornamental Plants in Florida. PLANT DISEASE 2016; 100:500-509. [PMID: 30694125 DOI: 10.1094/pdis-05-15-0598-re] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This report investigates population structure and genetic variability of Phytophthora spp. isolated from botanically diverse plants in Florida. Internal transcribed spacer-based molecular phylogenetic analyses indicate that Phytophthora isolates recovered from ornamental plants in Florida represent a genetically diverse population and that a majority of the isolates belong to Phytophthora nicotianae (73.2%), P. palmivora (18.7%), P. tropicalis (4.9%), P. katsurae (2.4%), and P. cinnamomi (0.8%). Mating type analyses revealed that most isolates were heterothallic, consisting of both mating type A1 (25.2%) and mating type A2 (39.0%), and suggesting that they could outcross. Fungicide sensitivity assays determined that several isolates were moderate to completely insensitive to mefenoxam. In addition, several isolates were also moderately insensitive to additional fungicides with different modes of action. However, correlation analyses did not reveal occurrence of fungicide cross-resistance. These studies suggest that a genetically diverse Phytophthora population infects ornamental crops and the occurrence of mefenoxam-insensitive Phytophthora populations raises concerns about disease management in ornamentals. Mitigating fungicide resistance will require prudent management strategies, including tank mixes and rotation of chemicals with different modes of actions.
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Affiliation(s)
- Jaimin S Patel
- Mid-Florida Research and Education Center and Department of Plant Pathology, University of Florida/Institute of Food and Agricultural Sciences, Apopka 32703
| | - Anne Vitoreli
- Tropical Research and Education Center, University of Florida/Institute of Food and Agricultural Sciences, Homestead 33031
| | - Aaron J Palmateer
- Tropical Research and Education Center, University of Florida/Institute of Food and Agricultural Sciences, Homestead 33031
| | - Ashraf El-Sayed
- Mid-Florida Research and Education Center and Department of Plant Pathology, University of Florida/Institute of Food and Agricultural Sciences, Apopka
| | - David J Norman
- Mid-Florida Research and Education Center and Department of Plant Pathology, University of Florida/Institute of Food and Agricultural Sciences, Apopka
| | - Erica M Goss
- Department of Plant Pathology, University of Florida, Institute of Food and Agricultural Sciences, Gainesville 32611-0680
| | - Mary S Brennan
- Mid-Florida Research and Education Center and Department of Plant Pathology, University of Florida/Institute of Food and Agricultural Sciences, Apopka
| | - Gul Shad Ali
- Mid-Florida Research and Education Center and Department of Plant Pathology, University of Florida/Institute of Food and Agricultural Sciences, Apopka
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23
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Saville A, Graham K, Grünwald NJ, Myers K, Fry WE, Ristaino JB. Fungicide Sensitivity of U.S. Genotypes of Phytophthora infestans to Six Oomycete-Targeted Compounds. PLANT DISEASE 2015; 99:659-666. [PMID: 30699679 DOI: 10.1094/pdis-05-14-0452-re] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Phytophthora infestans causes potato late blight, an important and costly disease of potato and tomato crops. Seven clonal lineages of P. infestans identified recently in the United States were tested for baseline sensitivity to six oomycete-targeted fungicides. A subset of the dominant lineages (n = 45) collected between 2004 and 2012 was tested in vitro on media amended with a range of concentrations of either azoxystrobin, cyazofamid, cymoxanil, fluopicolide, mandipropamid, or mefenoxam. Dose-response curves and values for the effective concentration at which 50% of growth was suppressed were calculated for each isolate. The US-8 and US-11 clonal lineages were insensitive to mefenoxam while the US-20, US-21, US-22, US-23, and US-24 clonal lineages were sensitive to mefenoxam. Insensitivity to azoxystrobin, cyazofamid, cymoxanil, fluopicolide, or mandipropamid was not detected within any lineage. Thus, current U.S. populations of P. infestans remained sensitive to mefenoxam during the displacement of the US-22 lineage by US-23 over the past 5 years.
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Affiliation(s)
- Amanda Saville
- Department of Plant Pathology, North Carolina State University, Raleigh 27695
| | - Kim Graham
- Horticultural Crops Research Laboratory, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Corvallis, OR
| | - Niklaus J Grünwald
- Horticultural Crops Research Laboratory, USDA-ARS; Department of Botany and Plant Pathology and Center for Genome Biology and Biocomputing, Oregon State University
| | - Kevin Myers
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University
| | - William E Fry
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University
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