Submitted to: Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2008
Publication Date: 3/1/2009
Citation: Li, S., Hartman, G.L., Chen, Y. 2009. Evaluation of Aggressiveness of Fusarium virguliforme Isolates That Cause Soybean Sudden Death Syndrome. Journal of Plant Pathology.91(1):77-86
Interpretive Summary: Soybean sudden death syndrome (SDS) is one of the most widespread and destructive fungal diseases of soybean and is caused by the soilborne fungus Fusarium virguliforme. SDS has become a widespread and recurring problem causing significant yield losses in many soybean-growing areas. The use of resistant cultivars is the most effective method for controlling SDS. Selection of aggressive (causing much disease) fungal isolates is important to evaluate resistance in soybean varieties. Differences among 30 fungal isolates were found based on measurements of disease. Of these 30 isolates, more than 10 isolates caused more disease than the isolate that is popularly used for field and greenhouse studies. These aggressive isolates can be used to identify soybean breeding lines with SDS resistance, thus improving soybean production where this disease occurs.
Technical Abstract: Greenhouse studies were conducted to compare the ability of fungal isolates that cause soybean sudden death syndrome (SDS). After an initial evaluation of 123 isolates on soybean, 30 were selected for further tests where both foliar severity and root infection were evaluated. Difference among isolates were found based on measurements of SDS foliar severity; shoot, root, and root lesion lengths; and shoot and root dry weights were found among isolates. Isolate FSG1 caused the lowest percentage shoot weight and shoot length of the control plants, but 11 isolates had higher foliar severity, and 15 isolates had longer root lesion length than the isolate FSG1. Identification of aggressive isolates will provide a useful tool for evaluating soybean breeding lines for SDS resistance.