Identification, Characterization, and Chemical Management of Fusarium asiaticum Causing Soybean Root Rot in Northeast China

Soybean root rot, a soil-borne fungal disease, is caused by multiple pathogens that seriously affect soybean production. During spring 2021, 92 pathogenic fungal strains were isolated from soybean plants with root rot in Hailun City, Heilongjiang Province, China. Through morphological and molecular identification, these strains were identified as Fusarium oxysporum (39.1%), F. asiaticum (30.4%), F. graminearum (13.0%), Pythium macrosporum (8.7%), and Rhizoctonia solani (8.7%). Among them, F. oxysporum was the dominant species, and F. asiaticum, not previously reported as a soybean root rot pathogen in Northeast China. Approximately 50% of the F. asiaticum isolates were moderately pathogenic. In addition, F. asiaticum had a wide host range, infecting black soybean, French bean, white hyacinth bean, mung bean, and adzuki bean but not corn, peanut, rice, and oat roots. Regarding field management, fludioxonil and pyraclostrobin had the best control effects of 73.8% and 69.4%, with EC50 values of 0.0029-0.0071 mu g<middle dot>mL-1 and 0.0045-0.0076 mu g<middle dot>mL-1, respectively. The study reported that F. asiaticum is a pathogen causing soybean root rot in northeast China. The application of chemical fungicides and non-host crop rotation can effectively control the disease caused by F. asiaticum.