1
|
Lin S, Peduto Hand F. Determining the Sources of Primary and Secondary Inoculum and Seasonal Inoculum Dynamics of Fungal Pathogens Causing Fruit Rot of Deciduous Holly. PLANT DISEASE 2019; 103:951-958. [PMID: 30880556 DOI: 10.1094/pdis-09-18-1694-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Fruit rot of deciduous holly, caused by species of the genera Alternaria, Colletotrichum, Diaporthe, and Epicoccum, is affecting plant production in Midwestern and Eastern U.S. nurseries. To determine the sources of inoculum, dormant twigs and mummified fruit were collected, and leaf spot development was monitored throughout the season from three Ohio nurseries over two consecutive years. Mummified fruit was the main source of primary inoculum for species of Alternaria and Epicoccum, whereas mummified fruit and bark were equally important for species of Colletotrichum and Diaporthe. Brown, irregular leaf spots developed in the summer, and disease incidence and severity increased along with leaf and fruit development. Coalesced leaf spots eventually resulted in early plant defoliation. When tested for their pathogenicity on fruit, leaf spot isolates were able to infect wounded mature fruit and induce rot symptoms, which indicated that leaf spots could serve as a source of secondary inoculum for fruit infections. In addition, spore traps were used to monitor seasonal inoculum abundance in the nurseries. Fruit rot pathogens were captured by the spore traps throughout the season, with peak dissemination occurring during flowering. In this study, we also attempted to understand the role of environmental factors on leaf spot development. Although leaf spot incidence and severity were negatively correlated to mean maximum, minimum and average temperature, a decrease in temperature also coincided with leaf senescence. The role of temperature on leaf spot development should be further studied to fully interpret these results.
Collapse
Affiliation(s)
- Shan Lin
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210
| | | |
Collapse
|
2
|
Lin S, Peduto Hand F. Investigations on the Timing of Fruit Infection by Fungal Pathogens Causing Fruit Rot of Deciduous Holly. PLANT DISEASE 2019; 103:308-314. [PMID: 30522396 DOI: 10.1094/pdis-06-18-0973-re] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Fruit rot of deciduous holly is an emerging fungal disease that is affecting plant production across midwestern and eastern U.S. nurseries. To determine the growth stage(s) of host susceptibility to infection by the major pathogens associated with the disease, Alternaria alternata and Diaporthe ilicicola, and minor pathogens such as Colletotrichum fioriniae and Epicoccum nigrum, we conducted two sets of experiments over two consecutive seasons. In the first case we monitored the presence of the pathogens as well as disease progression in a commercial nursery under natural conditions by collecting plant tissues from the flower bud stage until fruit maturity. The target pathogens were consistently isolated from asymptomatic samples at all stages of fruit development and from symptomatic samples at fruit maturity across the 2 years of collection. A significant increase in fungal isolation frequency, primarily species of Alternaria and Colletotrichum, was observed right after flowering, but fruit rot symptoms only developed on mature fruit. In the second case we artificially inoculated containerized plants maintained outdoor at our research farm with individual or combined pathogens at different fruit developmental stages, and we assessed disease incidence on mature fruit to determine the time of host susceptibility to infection and, indirectly, whether pathogens in the fungal complex carry out latent infections. D. ilicicola could cause latent infection on deciduous holly fruit when inoculated at the full bloom and petal fall stages, and all inoculations made on wounded mature fruit resulted in fruit rot. These findings suggest that flowering represents a critical period to manage D. ilicicola infections and that mature fruit should be protected from any injury to avoid disease. In both experiments a negative correlation between disease incidence and temperature was found; however, the decrease in temperature also coincided with fruit ripening. The effects of temperature and changes in physiological properties of the fruit during maturation on disease development should be further investigated to fully interpret these findings.
Collapse
Affiliation(s)
- Shan Lin
- Department of Plant Pathology, The Ohio State University, Columbus, 43210
| | | |
Collapse
|
3
|
Vasić M, Vico I, Jurick WM, Duduk N. Distribution and Characterization of Monilinia spp. Causing Apple Fruit Decay in Serbia. PLANT DISEASE 2018; 102:359-369. [PMID: 30673531 DOI: 10.1094/pdis-06-17-0867-re] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Brown rot, caused by Monilinia spp., is an economically important pre- and postharvest disease of pome and stone fruits worldwide. In Serbia, apple is the most widely grown pome fruit, and the distribution of economically important Monilinia spp. responsible for apple brown rot is unknown. Hence, we conducted a three year survey, from 2010 to 2012, where 349 isolates were obtained from six orchards and four storage facilities from five different apple cultivars with brown rot symptoms. Morphological characterization of the isolates, multiplex PCR, and phylogenetic analysis revealed four species: M. fructigena, M. laxa, M. fructicola, and Monilia polystroma. All species were found in the orchard and in storage, with M. fructigena predominating, followed by M. polystroma. Representative isolates were analyzed in vitro and in vivo where differences in growth rate, sporulation, and virulence on apple fruit were observed. Findings from this investigation demonstrate diversity in the species responsible for pre- and postharvest apple brown rot, which has significant implications for pathogen detection and for developing disease-specific management strategies.
Collapse
Affiliation(s)
- Miljan Vasić
- University of Belgrade, Faculty of Agriculture, Belgrade 11080, Serbia
| | - Ivana Vico
- University of Belgrade, Faculty of Agriculture, Belgrade 11080, Serbia
| | | | - Nataša Duduk
- University of Belgrade, Faculty of Agriculture, Belgrade 11080, Serbia
| |
Collapse
|
4
|
Fazekas M, Madar A, Sipiczki M, Miklós I, Holb IJ. Genetic diversity in Monilinia laxa populations in stone fruit species in Hungary. World J Microbiol Biotechnol 2014; 30:1879-92. [PMID: 24474390 DOI: 10.1007/s11274-014-1613-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
The objectives of this study were firstly, to determine the genetic diversity of Monilinia laxa isolates from Hungary, using the PCR-based inter-simple sequence repeat (ISSR) and randomly amplified polymorphic DNA (RAPD) technique; secondly, to prepare genetic diversity groups based on the dendrograms; and finally, to select some relevant isolates to study their fungicide sensitivity. 55 and 77 random amplified polymorphic ISSR and RAPD markers, of which 23 and 18 were polymorphic and 32 and 59 monomorphic, respectively, were used to assess the genetic diversity and to study the structure of M. laxa populations in Hungary. 27 isolates out of 57 ones were confirmed as M. laxa from several orchards (subpopulations) in three geographical regions, in various inoculum sources and in various hosts, were used. 10 fungicides and 12 isolates selected from genetic diversity groups based on the ISSR dendrograms were used to determine the fungicide sensitivity of the selected isolates. The analysis of population structure revealed that genetic diversity within locations, inoculum sources and host (H(S)) accounted for 99 % of the total genetic diversity (H(T)), while genetic diversity among locations, inoculum sources and host represented only 1 %. The relative magnitude of gene differentiation between subpopulations (G(ST)) and the estimate of the number of migrants per generation (Nm) averaged 0.005-0.009 and 53.9-99.2, respectively, for both ISSR and RAPD data set. The results obtained in dendrograms were in accordance with the gene diversity analysis. Grouping of isolates in the dendrograms was irrespective of whether they came from the same or different geographical locations. There was no relationship between clustering among isolates from inoculum sources and hosts. In the fungicide sensitivity tests, five isolates out of 12 were partly insensitive to boscalid+piraclostrobin, cyprodinil, fenhexamid or prochloraz. Obtained results in genetic diversity of M. laxa populations are discussed together with implications for the management of brown rot.
Collapse
Affiliation(s)
- Mónika Fazekas
- University of Debrecen, P.O. Box 36, 4015, Debrecen, Hungary
| | | | | | | | | |
Collapse
|
5
|
Everhart SE, Askew A, Seymour L, Holb IJ, Scherm H. Characterization of three-dimensional spatial aggregation and association patterns of brown rot symptoms within intensively mapped sour cherry trees. ANNALS OF BOTANY 2011; 108:1195-202. [PMID: 21335328 PMCID: PMC3189829 DOI: 10.1093/aob/mcr029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 01/07/2011] [Indexed: 05/11/2023]
Abstract
BACKGROUND AND AIMS Characterization of spatial patterns of plant disease can provide insights into important epidemiological processes such as sources of inoculum, mechanisms of dissemination, and reproductive strategies of the pathogen population. Whilst two-dimensional patterns of disease (among plants within fields) have been studied extensively, there is limited information on three-dimensional patterns within individual plant canopies. Reported here are the detailed mapping of different symptom types of brown rot (caused by Monilinia laxa) in individual sour cherry tree (Prunus cerasus) canopies, and the application of spatial statistics to the resulting data points to determine patterns of symptom aggregation and association. METHODS A magnetic digitizer was utilized to create detailed three-dimensional maps of three symptom types (blossom blight, shoot blight and twig canker) in eight sour cherry tree canopies during the green fruit stage of development. The resulting point patterns were analysed for aggregation (within a given symptom type) and pairwise association (between symptom types) using a three-dimensional extension of nearest-neighbour analysis. KEY RESULTS Symptoms of M. laxa infection were generally aggregated within the canopy volume, but there was no consistent pattern for one symptom type to be more or less aggregated than the other. Analysis of spatial association among symptom types indicated that previous year's twig cankers may play an important role in influencing the spatial pattern of current year's symptoms. This observation provides quantitative support for the epidemiological role of twig cankers as sources of primary inoculum within the tree. CONCLUSIONS Presented here is a new approach to quantify spatial patterns of plant disease in complex fruit tree canopies using point pattern analysis. This work provides a framework for quantitative analysis of three-dimensional spatial patterns within the finite tree canopy, applicable to many fields of research.
Collapse
Affiliation(s)
| | - Ashley Askew
- Department of Statistics, University of Georgia, Athens, GA 30602, USA
| | - Lynne Seymour
- Department of Statistics, University of Georgia, Athens, GA 30602, USA
| | - Imre J. Holb
- Center for Agricultural Sciences, University of Debrecen, H-4015 Debrecen, Hungary
- Plant Protection Institute, Hungarian Academy of Sciences, H-1525 Budapest, Hungary
| | | |
Collapse
|
6
|
Pest risk assessment ofMonilinia fructicolafor the EU territory and identification and evaluation of risk management options. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2119] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
7
|
Holb IJ, Gáll JM, Fodor B. Effect of Production System and Pruning on Temporal Development of Cercospora depazeoides and on Berry Yield in Black Elderberry Orchards. PLANT DISEASE 2009; 93:625-631. [PMID: 30764401 DOI: 10.1094/pdis-93-6-0625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In a 2-year study, the temporal development of Cercospora leaf spot (Cercospora depazeoides) and berry yield were evaluated in two production systems (integrated and organic) and in two winter pruning treatments (trees pruned to four and eight scaffolds) in two black elderberry (Sambucus nigra) orchards in Hungary. Under organic production, leaf spot onset occurred 2 to 4 weeks earlier (mid- and late July) in both years and both orchards compared with the integrated program. Disease then continuously progressed until the final assessment date (late September) in both years, reaching a maximum final disease incidence of 15.9% in the integrated system and of 38.2% in the organic system. In general, disease progress after late August was greater on trees pruned to eight scaffolds than on trees pruned to four scaffolds in both production systems. Both final disease incidence and area under the disease progress curves (AUDPC) were significantly lower (P < 0.001) in the integrated treatments compared with organic ones. Across all treatments, both disease measures were significantly (P < 0.05) lower on trees pruned to four scaffolds compared with trees pruned to eight scaffolds. However, when the effect of pruning on final disease incidence and AUDPC was analyzed separately for integrated and organic systems, pruning caused uniformly significant differences in disease development only for the organic system. Berry yield was significantly higher (P < 0.05) in the integrated system compared with the organic system, but pruning showed no significant effect on yield. Overall, pruning to four scaffolds resulted in consistently lower disease development in organic production compared to integrated. Thus, winter pruning may be useful as a Cercospora leaf spot management practice in organic elderberry orchards.
Collapse
Affiliation(s)
- I J Holb
- University of Debrecen, Centre for Agricultural Sciences and Engineering, P.O. Box 36, H-4015 Debrecen, Hungary and Plant Protection Institute, Hungarian Academy of Sciences, P.O. Box 102, H-1525 Budapest, Hungary
| | - J M Gáll
- University of Debrecen, Institute of Mathematics and Informatics, P.O. Box 15, H-4015 Debrecen, Hungary
| | - B Fodor
- University of Debrecen, Centre for Agricultural Sciences and Engineering, P.O. Box 36, H-4015 Debrecen, Hungary
| |
Collapse
|
8
|
Holb IJ, Scherm H. Quantitative relationships between different injury factors and development of brown rot caused by Monilinia fructigena in integrated and organic apple orchards. PHYTOPATHOLOGY 2008; 98:79-86. [PMID: 18943241 DOI: 10.1094/phyto-98-1-0079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In a 4-year study, the incidence of various types of injuries (caused by insects, birds, growth cracks, mechanical wounding, and other, unidentified factors) was assessed in relation to brown rot development (caused by Monilinia fructigena) on fruit of three apple cultivars (Prima, Jonathan, and Mutsu) in integrated and organic blocks of two apple orchards in Hungary. In addition, populations of male codling moths (Cydia pomonella) were monitored with pheromone traps season-long in both management systems. On average, injury incidence on fruit at harvest was 6.1 and 19.2% in the integrated and organic treatments, respectively. Insect injury, which was caused primarily by C. pomonella, had the highest incidence among the five injury types, accounting for 79.4% of the total injury by harvest in the organic blocks and 36.6% in the integrated blocks. Levels of all other injury types remained close to zero during most of the season, but the incidence of bird injury and growth cracks increased markedly in the final 3 to 5 weeks before harvest in both production systems. Brown rot developed more slowly and reached a lower incidence in the integrated (6.4% final incidence on average) compared with the organic blocks (20.1% average incidence). In addition, the disease developed later but attained higher levels as the cultivar ripening season increased from early-maturing Prima to late-maturing Mutsu. Overall, 94.3 to 98.7% of all injured fruit were also infected by M. fructigena, whereas the incidence of brown-rotted fruit without visible injury was very low (0.8 to 1.6%). Correlation coefficients (on a per plot basis) and association indices (on a per-fruit basis) were calculated between brown rot and the various injury types for two selected assessment dates 4 weeks preharvest and at harvest. At both dates, the strongest significant (P < 0.05) relationships were observed between brown rot and insect injury and between brown rot and the cumulative number of trapped C. pomonella. At the harvest assessment, two additional significant correlations were between brown rot and bird injury and between brown rot and growth cracks. In every case, correlation coefficients were larger in organic than in integrated blocks. Although it is well established that brown rot in pome fruits is closely associated with fruit injuries, this is the first study to provide season-long progress data on different injury types and quantitative analyses of their relative importance at different times in the growing season and across two distinct management systems.
Collapse
Affiliation(s)
- I J Holb
- Centre of Agricultural Sciences, University of Debrecen, P.O. Box 36, H-4015 Debrecen, Hungray.
| | | |
Collapse
|