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POSTERS: Population biology and genetics

Global Population structure of Fusarium virguliforme based on microsatellite marker analysis
Huan Tian - Purdue University. Tomara J. Fleury- USDA-ARS, Guohong Cai- USDA-ARS / Purdue University, Teresa Hughes- Monsanto Co, Kiersten Wise- University of Kentucky

Fusarium virguliforme is a soilborne pathogen and the causal agent of soybean sudden death syndrome (SDS) in the USA. Since the first observation in Arkansas in the 1971, SDS has been reported in 22 states. SDS has also been reported in Canada, South America and South Africa and F. virguliforme was found in the soil in Malaysia. In South America, SDS can also be caused by several other Fusarium species. In an effort to examine global population structure of F. virguliforme, a collection of isolates, 34 from Argentina and 56 from the USA, were genotyped using microsatellite markers. Bioinformatics mining of four F. virguliforme genomes and experimental validation identified 16 polymorphic microsatellite markers and these markers were used to fingerprint these isolates. In total, 37 multi-locus genotypes (MLGs) were identified. USA isolates were distributed among 27 MLGs while Argentina isolates were distributed among 11 MLGs. Majority of our Argentina isolates were clustered with USA isolates collected from Indiana, Iowa, Arkansas and Illinois. Several diversity indexes, including the average number of different alleles, the number of effective alleles, and Shannon’s diversity index, showed that the USA isolates were more diverse than Argentina isolates. We are currently collecting more isolates from geographic regions not represented or under-represented in our collection.