|Achenbach, Laurie - SOUTHERN IL UNIV|
|Patrick, Jennifer - UNIV OF ILLINOIS|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 30, 1996
Publication Date: N/A
Interpretive Summary: Soybean sudden death syndrome is a relatively new soybean disease. Under favorable weather conditions severe yield losses are associated with this disease. A fungal pathogen identified as Fusarium solani f. sp. phaseoli causes this disease. It is not known how variable genetically individuals (called isolates) of this fungus are in farmers fields. The present work was undertaken to determine if certain molecular techniques could be used to determine the amount of genetic variability present in this important soybean fungal pathogen. A collection of individuals of the fungus were examined along with other species of Fusarium that do not cause soybean sudden death syndrome by comparing differences in DNA patterns. It was found that the SDS Fusarium individuals were distinct from other Fusarium species based on differences in DNA. There were two distinct groups of SDS individuals based on differences in DNA. This molecular procedure is fast, reproducible and can be used to distinguish SDS from non-SDS individuals. The results from this work should be useful to other soybean plant pathologists working on soybean sudden death syndrome.
Technical Abstract: Fusarium solani is the etiological agent of soybean sudden death syndrome (SDS). Random amplified polymorphic DNA (RAPD) analysis was used to differentiate those isolates that cause SDS from those that do not. Greenhouse assays using a sand/cornmeal inoculum method were performed to assess pathogenicity of the fungal isolates and the results were compared with the RAPD pattern analysis. The RAPD approach proved a sensitive and highly reliable method for quickly identifying fungal pathotypes that caused SDS. Amplification patterns generated by RAPD reactions were used to generate a phenogram depicting the monophyletic nature of the cluster defined by the SDS isolates. This cluster was exclusive and distinct from F. solani F. sp. phaseoli isolates that do not cause SDS. Based on these results, we propose that fungal isolates capable of causing soybean SDS be classified F. solani f. sp. glycines.