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

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 in the United States

2017 ◽  
Author(s):  
Zhian N Kamvar ◽  
Bimal S Amaradasa ◽  
Rachana Jhala ◽  
Serena McCoy ◽  
James R Steadman ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sclerotinia Sclerotiorum ◽  
Genotypic Variation ◽  
Natural Populations ◽  
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, Mexico, France, and Australia 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 Mycelial compatibility and aggressiveness of Sclerotinia sclerotiorum isolates from Brazil and the United States

2014 ◽  
Vol 49 (4) ◽  
pp. 265-272 ◽  
Author(s):  
Lucimara Junko Koga ◽  
Charles Roger Bowen ◽  
Claudia Vieira Godoy ◽  
Maria Cristina Neves de Oliveira ◽  
Glen Lee Hartman
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Sclerotinia Sclerotiorum ◽  
Country Of Origin ◽  
The United States ◽  
Soybean Field ◽  
Soybean Cultivars ◽  
Mycelial Compatibility ◽  
The Usa ◽  
Midwest Region

The objective of this work was to evaluate the genetic diversity among Sclerotinia sclerotiorum isolates from Brazil and the USA, assess their aggressiveness variability, and verify the existence of an isolate-cultivar interaction. Isolate variability was determined by mycelial compatibility grouping (MCG), and isolate aggressiveness by cut-stem inoculations of soybean cultivars. Two experiments for MCGs and two for aggressiveness were conducted with two sets of isolates. The first set included nine isolates from the same soybean field in Brazil and nine from the Midwest region of the USA. The second set included 16 isolates from several regions of Brazil and one from the USA. In the first set, 18 isolates formed 12 different MCGs. In the second set, 81% of the isolates from Brazil grouped into a single MCG. No common MCGs were observed among isolates from Brazil and the USA. The isolates showed aggressiveness differences in the first set, but not in the second. Although aggressiveness differed in the first set, soybean cultivars and isolates did not interact significantly. Cultivar rank remained the same, regardless of the genetic diversity, aggressiveness difference, and region or country of origin of the isolate. Results from screening of soybean cultivars, performed by the cut-stem method in the USA, can be used as reference for researchers in Brazil.

scholarly journals Variation in Sclerotinia sclerotiorum Bean Isolates from Multisite Resistance Screening Locations

Plant Disease ◽  
2011 ◽  
Vol 95 (11) ◽  
pp. 1370-1377 ◽  
Author(s):  
Lindsey Otto-Hanson ◽  
James R. Steadman ◽  
Rebecca Higgins ◽  
Kent M. Eskridge
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
The United States ◽  
White Mold ◽  
Resistance Screening ◽  
Dry Bean ◽  
Mycelial Compatibility ◽  
Greenhouse Screening ◽  
Mold Resistance ◽  
Production Areas ◽  
Resistance Expression

There is no complete resistance to Sclerotinia sclerotiorum, cause of white mold in dry bean (Phaseolus vulgaris). Variable resistance expression is one problem in screening for improved white mold resistance. With no previous information in the literature, pathogen variation in multisite screening nurseries was evaluated as one cause of diverse resistance expression. In all, 10 isolates of S. sclerotiorum used in greenhouse screening and 146 isolates collected from nine white mold field screening nurseries in major bean production areas in the United States were compared using mycelial compatibility groupings (MCGs) and an aggressiveness test. These 10 greenhouse screening isolates formed six MCGs. Among 156 field and greenhouse isolates, 64 MCGs were identified and 36 of those were each composed of a single unique isolate. Significant differences in isolate aggressiveness were found between some isolates in different MCGs but the isolates within an MCG did not differ in aggressiveness. High isolate variation found within and between field locations could influence the disease phenotype of putative white mold resistant germplasm. We next compared genotype and phenotype of isolates from screening nurseries and those from producer fields. Variability found in and among screening locations did reflect variability found in the four producer fields sampled. White mold resistance screening can be improved by knowledge of isolate genotypic and phenotypic characteristics.

scholarly journals Molecular Analysis of a Plum pox virus W Isolate in Plum Germplasm Hand Carried into the USA from the Ukraine Shows a Close Relationship to a Latvian Isolate

Plant Disease ◽  
2013 ◽  
Vol 97 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Vessela Mavrodieva ◽  
Delano James ◽  
Karen Williams ◽  
Sarika Negi ◽  
Aniko Varga ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
The United States ◽  
Common Source ◽  
Plum Pox Virus ◽  
High Genetic Diversity ◽  
Close Relationship ◽  
The Usa ◽  
Sequence Identities ◽  
Germplasm Accessions

Four of 19 Prunus germplasm accessions hand carried from the Ukraine into the United States without authorization were found to be infected with Plum pox virus (PPV). Of the three isolates characterized, isolates UKR 44189 and UKR 44191 were confirmed to be isolates of PPV strain W, and UKR 44188 was confirmed to be an isolate of PPV strain D. UKR 44189 and UKR 44191 are very closely related to the PPV strain W isolate LV-145bt (HQ670748) from Latvia. Nucleotide and amino acid sequence identities between these three isolates were greater than 99%. This indicates that the isolates are very closely related and likely originated from a common source. The high genetic diversity among PPV-W strain isolates allowed the identification of potential recombination events between PPV isolates. It appears also that GF 305 peach and Prunus tomentosa are not hosts for the PPV isolate UKR 44189.

Genetic Diversity of Wild Oat (Avena fatua)Populations from China and the United States

Weed Science ◽  
2007 ◽  
Vol 55 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Runzhi Li ◽  
Shiwen Wang ◽  
Liusheng Duan ◽  
Zhaohu Li ◽  
Michael J. Christoffers ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
The United States ◽  
Mantel Test ◽  
Wild Oat ◽  
Chinese Populations ◽  
Nei's Distance ◽  
The Impact

Weed genetic diversity is important for understanding the ability of weeds to adapt to different environments and the impact of herbicide selection on weed populations. Genetic diversity within and among six wild oat populations in China varying in herbicide selection pressure and one population in North Dakota were surveyed using 64 polymorphic alleles resulting from 25 microsatellite loci. Mean Nei's gene diversity (h) for six wild oat populations from China was between 0.17 and 0.21, and total diversity (HT) was 0.23. A greater proportion of this diversity, however, was within (Hs= 0.19) rather than among (Gst= 0.15) populations. For the wild oat population from the United States,h= 0.24 andHT= 0.24 were comparable to the values for the six populations from China. Cluster analysis divided the seven populations into two groups, where one group was the United States population and the other group included the six Chinese populations. The genetic relationships among six populations from China were weakly correlated with their geographic distribution (r= 0.22) using the Mantel test. Minimal difference in gene diversity and small genetic distance (Nei's distance 0.07 or less) among six populations from China are consistent with wide dispersal of wild oat in the 1980s. Our results indicate that the wild oat populations in China are genetically diverse at a level similar to North America, and the genetic diversity of wild oat in the broad spatial scale is not substantially changed by environment, agronomic practices, or herbicide usage.

Sign in / Sign up

Export Citation Format

Share Document