This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Pannullo A, Kamvar ZN, Miorini TJJ, Steadman JR, Everhart SE.2018. Genetic variation and structure of Sclerotinia sclerotiorum populations from soybean in Brazil. PeerJ Preprints6:e26600v1https://doi.org/10.7287/peerj.preprints.26600v1
The clonal, necrotrophic plant pathogen, Sclerotinia sclerotiorum is the causal agent of white mold on soybean, causing significant losses for Brazilian farmers each year. While assessments of population structure and clonal dynamics can be beneficial for determining effective management strategies, few studies have been performed. In this paper, we present a broad-scale population genetic analysis with 11 microsatellite loci of 94 isolates of S. sclerotiorum from soybean fields in nine Brazilian states (N=74) with Argentina (N=5) and the United States (N=15) as outgroups. Genotyping identified 87 multilocus genotypes with 81 represented by a single isolate. The pattern of genetic diversity observed suggested populations were not strongly differentiated because despite the high genetic diversity, there were few private alleles/genotypes and no multilocus genotypes were identified in both South and North America while one multilocus genotype was shared between Argentina and Brazil. Pairwise analysis of molecular variance between populations in Brazil revealed nine out of 15 pairs significantly different (P > 0.05). The population from the U.S. was most strongly differentiated in across all measures of population differentiation. Overall, our results found evidence for gene flow across populations with a moderate amount of population structure within states in Brazil. We additionally found shared genotypes across populations in Brazil and Argentina, suggesting that sclerotia may be transferred across states either through seeds or shared equipment. This represents the first population genetic study to cover a wide area in Brazil.
This has been submitted to Tropical Plant Pathology.