scholarly journals Peer Review #3 of "Population structure and phenotypic variation of Sclerotinia sclerotiorum from dry bean (Phaseolus vulgaris) in the United States (v0.1)"

2017 ◽  
Keyword(s):  
United States ◽  
Population Structure ◽  
Phaseolus Vulgaris ◽  
Peer Review ◽  
Sclerotinia Sclerotiorum ◽  
Phenotypic Variation ◽  
The United States ◽  
Dry Bean

scholarly journals Population structure and phenotypic variation of Sclerotinia sclerotiorum from dry bean (Phaseolus vulgaris) in the United States

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4152 ◽  
Author(s):  
Zhian N. Kamvar ◽  
B. Sajeewa Amaradasa ◽  
Rachana Jhala ◽  
Serena McCoy ◽  
James R. Steadman ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Sclerotinia Sclerotiorum ◽  
Genotypic Variation ◽  
The United States ◽  
White Mold ◽  
Bipartite Network ◽  
Necrotrophic Pathogen ◽  
Dry Bean ◽  
Field Source

The ascomycete pathogen Sclerotinia sclerotiorum is a necrotrophic pathogen on over 400 known host plants, and is the causal agent of white mold on dry bean. Currently, there are no known cultivars of dry bean with complete resistance to white mold. For more than 20 years, bean breeders have been using white mold screening nurseries (wmn) with natural populations of S. sclerotiorum to screen new cultivars for resistance. It is thus important to know if the genetic diversity in populations of S. sclerotiorum within these nurseries (a) reflect the genetic diversity of the populations in the surrounding region and (b) are stable over time. Furthermore, previous studies have investigated the correlation between mycelial compatibility groups (MCG) and multilocus haplotypes (MLH), but none have formally tested these patterns. We genotyped 366 isolates of S. sclerotiorum from producer fields and wmn surveyed over 10 years in 2003–2012 representing 11 states in the United States of America, Australia, France, and Mexico at 11 microsatellite loci resulting in 165 MLHs. Populations were loosely structured over space and time based on analysis of molecular variance and discriminant analysis of principal components, but not by cultivar, aggressiveness, or field source. Of all the regions tested, only Mexico (n = 18) shared no MLHs with any other region. Using a bipartite network-based approach, we found no evidence that the MCGs accurately represent MLHs. Our study suggests that breeders should continue to test dry bean lines in several wmn across the United States to account for both the phenotypic and genotypic variation that exists across regions.

scholarly journals Population structure and phenotypic variation of Sclerotinia sclerotiorum from dry bean (Phaseolus vulgaris) in the United States

2017 ◽  
Author(s):  
Zhian N Kamvar ◽  
Bimal S Amaradasa ◽  
Rachana Jhala ◽  
Serena McCoy ◽  
James R Steadman ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Sclerotinia Sclerotiorum ◽  
Genotypic Variation ◽  
The United States ◽  
White Mold ◽  
Bipartite Network ◽  
Necrotrophic Pathogen ◽  
Dry Bean ◽  
Field Source

The ascomycete pathogen Sclerotinia sclerotiorum is a necrotrophic pathogen on over 400 known host plants, and is the causal agent of white mold on dry bean. Currently, there are no known cultivars of dry bean with complete resistance to white mold. For more than 20 years, bean breeders have been using white mold screening nurseries with natural populations of S. sclerotiorum to screen new cultivars for resistance. It is thus important to know if the genetic diversity in populations of S. sclerotiorum within these nurseries a) reflect the genetic diversity of the populations in the surrounding region and b) are stable over time. Furthermore, previous studies have investigated the correlation between mycelial compatibility groups (MCG) and multilocus haplotypes (MLH), but none have formally tested these patterns. We genotyped 366 isolates of S. sclerotiorum from producer fields and white mold screening nurseries surveyed over 10 years in 2003–2012 representing 11 states in the United States of America, Australia, France, and Mexico at 11 microsatellite loci resulting in 165 MLHs. Populations were loosely structured over space and time based on analysis of molecular variance and discriminant analysis of principal components, but not by cultivar, aggressiveness, or field source. Of all the regions tested, only Mexico (n=18) shared no MLHs with any other region. Using a bipartite network-based approach, we found no evidence that the MCGs accurately represent MLHs. Our study suggests that breeders should continue to test dry bean lines in several white mold screening nurseries across the US to account for both the phenotypic and genotypic variation that exists across regions.

scholarly journals Population structure and phenotypic variation of Sclerotinia sclerotiorum from dry bean (Phaseolus vulgaris) in the United States

2017 ◽  
Author(s):  
Zhian N Kamvar ◽  
Bimal S Amaradasa ◽  
Rachana Jhala ◽  
Serena McCoy ◽  
James R Steadman ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Sclerotinia Sclerotiorum ◽  
Genotypic Variation ◽  
The United States ◽  
White Mold ◽  
Bipartite Network ◽  
Necrotrophic Pathogen ◽  
Dry Bean ◽  
Field Source

The ascomycete pathogen Sclerotinia sclerotiorum is a necrotrophic pathogen on over 400 known host plants, and is the causal agent of white mold on dry bean. Currently, there are no known cultivars of dry bean with complete resistance to white mold. For more than 20 years, bean breeders have been using white mold screening nurseries with natural populations of S. sclerotiorum to screen new cultivars for resistance. It is thus important to know if the genetic diversity in populations of S. sclerotiorum within these nurseries a) reflect the genetic diversity of the populations in the surrounding region and b) are stable over time. Furthermore, previous studies have investigated the correlation between mycelial compatibility groups (MCG) and multilocus haplotypes (MLH), but none have formally tested these patterns. We genotyped 366 isolates of S. sclerotiorum from producer fields and white mold screening nurseries surveyed over 10 years in 2003–2012 representing 11 states in the United States of America, Australia, France, and Mexico at 11 microsatellite loci resulting in 165 MLHs. Populations were loosely structured over space and time based on analysis of molecular variance and discriminant analysis of principal components, but not by cultivar, aggressiveness, or field source. Of all the regions tested, only Mexico (n=18) shared no MLHs with any other region. Using a bipartite network-based approach, we found no evidence that the MCGs accurately represent MLHs. Our study suggests that breeders should continue to test dry bean lines in several white mold screening nurseries across the US to account for both the phenotypic and genotypic variation that exists across regions.

Efficacy of three greenhouse screening methods for the identification of physiological resistance to white mold in dry bean

2009 ◽  
Vol 89 (4) ◽  
pp. 755-762 ◽  
Author(s):  
H Terán ◽  
S P Singh
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Sclerotinia Sclerotiorum ◽  
Screening Method ◽  
White Mold ◽  
Screening Methods ◽  
Post Inoculation ◽  
Dry Bean ◽  
Physiological Resistance ◽  
Nueva Granada

White mold (WM) caused by Sclerotinia sclerotiorum (Lib.) de Bary is the most devastating disease of common bean (dry and snap or garden bean) (Phaseolus vulgaris L.) in North America. The use of a reliable screening method (SM) in common bean is crucial to improve physiological resistance to WM. The objective of this study was to compare the efficacy of three SM to identify physiological resistance in dry bean genotypes with different evolutionary origins and levels of resistance. Screening methods tested were: (i) the modified straw test or cut–stem (CSM); (ii) infected bean flower (IFL); and (iii) infected oat seed (IOS). A 195, ICA Bunsi, Othello, and VCW 54 dry bean were tested with the three SM. The experimental design was a split plot in randomized complete blocks with three replications in 2007 and 2008. Two independent inoculations 1 wk apart for each SM were made. The WM reaction was scored at 16, 23, and 33 d post-inoculation (DPI) using a 1 to 9 scale. There were highly significant differences between SM and its interaction with years. The CSM and IFL were the most consistent and highly correlated (r > 0.70, P < 0.01). Interspecific breeding line VCW 54 consistently had the highest WM resistance across years, SM, and evaluation dates, followed by A 195. White mold scores increased with delayed evaluations. Thus, CSM or IFL with disease assessed 33 DPI should be used for identifying common bean genotypes with high levels of physiological resistance to WM.Key words: Common bean, growth habit, race Mesoamerica, race Nueva Granada, Phaseolus vulgaris, Sclerotinia sclerotiorum

scholarly journals First Report of Sclerotinia sclerotiorum on Campanula carpatica and Schizanthus × wisetonensis in Italy

Plant Disease ◽  
2002 ◽  
Vol 86 (1) ◽  
pp. 71-71
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino
Keyword(s):  
United States ◽  
Sclerotinia Sclerotiorum ◽  
Ornamental Plants ◽  
Soil Surface ◽  
The United States ◽  
First Report ◽  
Potted Plants ◽  
Initial Symptoms ◽  
Stem Necrosis ◽  
Campanula Carpatica

The production of potted ornamental plants is very important in the Albenga Region of northern Italy, where plants are grown for export to central and northern Europe. During fall 2000 and spring 2001, sudden wilt of tussock bellflower (Campanula carpatica Jacq.) and butterfly flower (Schizanthus × wisetonensis Hort.) was observed on potted plants in a commercial greenhouse. Initial symptoms included stem necrosis at the soil line and yellowing and tan discoloration of the lower leaves. As stem necrosis progressed, infected plants growing in a peat, bark compost, and clay mixture (70-20-10) wilted and died. Necrotic tissues were covered with whitish mycelia that produced dark, spherical (2 to 6 mm diameter) sclerotia. Sclerotinia sclerotiorum was consistently recovered from symptomatic stem pieces of both plants disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with streptomycin sulphate at 100 ppm. Pathogenicity of three isolates obtained from each crop was confirmed by inoculating 45- to 60-day-old C. carpatica and Schizanthus × wisetonensis plants grown in containers (14 cm diameter). Inoculum that consisted of wheat kernels infested with mycelia and sclerotia of each isolate was placed on the soil surface around the base of previously artificially wounded or nonwounded plants. Noninoculated plants served as controls. All plants were maintained outdoors where temperatures ranged between 8 and 15°C. Inoculated plants developed symptoms of leaf yellowing, followed by wilt, within 7 to 10 days, while control plants remained symptomless. White mycelia and sclerotia developed on infected tissues and S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of stem blight of C. carpatica and Schizanthus × wisetonensis caused by S. sclerotiorum in Italy. The disease was previously observed on C. carpatica in Great Britain (2) and on Schizanthus sp. in the United States (1). References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) J. Rees. Welsh J. Agric. 1:188, 1925.

scholarly journals Population structure of Drosophila suzukii and signals of multiple invasions into the continental United States

2021 ◽  
Author(s):  
Kyle M Lewald ◽  
Antoine Abrieux ◽  
Derek A Wilson ◽  
Yoosook Lee ◽  
William R Conner ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Population Structure ◽  
Weather Conditions ◽  
The United States ◽  
Future Research ◽  
Drosophila Suzukii ◽  
Significant Damage ◽  
Wide Range ◽  
Multiple Invasions

Drosophila suzukii, or spotted-wing drosophila, is now an established pest in many parts of the world, causing significant damage to numerous fruit crop industries. Native to East Asia, D. suzukii infestations started in the United States a decade ago, occupying a wide range of climates. To better understand invasion ecology of this pest, knowledge of past migration events, population structure, and genetic diversity is needed. To improve on previous studies examining genetic structure of D. suzukii, we sequenced whole genomes of 237 individual flies collected across the continental U.S., as well as several representative sites in Europe, Brazil, and Asia, to identify hundreds of thousands of genetic markers for analysis. We analyzed these markers to detect population structure, to reconstruct migration events, and to estimate genetic diversity and differentiation within and among the continents. We observed strong population structure between West and East Coast populations in the U.S., but no evidence of any population structure North to South, suggesting there is no broad-scale adaptations occurring in response to the large differences in regional weather conditions. We also find evidence of repeated migration events from Asia into North America have provided increased levels of genetic diversity, which does not appear to be the case for Brazil or Europe. This large genomic dataset will spur future research into genomic adaptations underlying D. suzukii pest activity and development of novel control methods for this agricultural pest.

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