Sources of Resistance, Effect of Maturity Groups, and Marker-Trait Associations Associated with Fusarium graminearum Causing Root Rot of Soybean (Glycine max)

Abstract

Fusarium graminearum Schwabe is an important fungus causing root rot of soybean ( Glycine max L.) in the United States. In this study, 248 accessions (including the susceptible check ‘Williams 82’) from the United States Department of Agriculture germplasm collection (maturity group [MG] 0 to V) were screened with a single isolate of F. graminearum using the inoculum layer inoculation method in the greenhouse to identify resistant parental materials. Disease severity was evaluated 21 days postinoculation on a 1-to-5 rating scale and expressed as relative treatment effects (RTEs). Eight accessions (PI437949, PI438292, PI612761A, PI438094B, PI567301B, PI408309, PI361090, and P188788) had significantly lower RTEs when compared with Williams 82 based on 95% confidence intervals. Furthermore, the effect of MGs on disease severity was assessed, and accessions belonging to MG 0 or I had significantly greater RTEs than cultivars belonging to MGs II to V based on 95% confidence intervals. A genome-wide association study analysis was conducted using 42,079 single-nucleotide markers, and six marker-trait associations were identified that may be novel sources of F. graminearum resistance. The identification of new resistant parental materials and MTAs associated with resistance to F. graminearum will be useful in breeding programs for developing resistant cultivars. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .