Abstract
Sudden death syndrome (SDS) of soybean is a damaging disease caused by the fungus Fusarium virguliforme. Since this pathogen was first reported in the southern U.S. state of Arkansas in 1971, it has spread throughout the midwestern United States. The SDS pathogen primarily colonizes roots but also produces toxins that translocate to and damage leaves. Previous studies have detected little to no genetic differentiation among isolates, suggesting F. virguliforme in North America has limited genetic diversity and a clonal population structure. Yet, isolates vary in virulence to roots and leaves. We characterized a set of F. virguliforme isolates from the midwestern United States, representing a south to north latitudinal gradient from Arkansas to Minnesota. Ten previously tested microsatellite loci were used to genotype isolates, and plant assays were conducted to assess virulence. Three distinct population clusters were differentiated across isolates. Although isolates ranged in virulence classes from low to very high, little correlation was found between virulence phenotype and cluster membership. Similarly, population structure and geographic location were not highly correlated. However, the earliest diverging cluster had the lowest genetic diversity and was detected only in southern states, whereas the two other clusters were distributed across the Midwest and were predominant in Minnesota. One of the midwestern clusters had the greatest genetic diversity and was found along the northern edge of the known distribution. The results support three genetically distinct population clusters of F. virguliforme in the United States, with two clusters contributing most to spread of this fungus across theMidwest.
Original language | English (US) |
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Pages (from-to) | 1273-1283 |
Number of pages | 11 |
Journal | Phytopathology |
Volume | 112 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2022 |
Bibliographical note
Funding Information:Funding: Funding for this study was provided by the Minnesota Invasive Terrestrial Plants and Pests Center through the Minnesota Environment and Natural Resources Trust Fund.
Publisher Copyright:
© 2022 The American Phytopathological Society.
Keywords
- Fusarium virguliforme
- invasive pathogen
- microsatellite
- population structure
- soybean
- sudden death syndrome
- virulence