No Common Candidate Genes for Resistance to , , , and in Soybean Accessions from Maturity Groups 0 and I: Findings from Genome-wide Association Mapping.

Seedling diseases and root rot, caused by species of , can limit soybean ( L.) production in the United States. Currently, there are few commercially available cultivars resistant to . This study was conducted to assess the resistance of soybean maturity group (MG) accessions from 0 and I to , , and , as well as to identify common quantitative trait loci (QTLs) for resistance to these pathogens, in addition to , using a genome-wide association study (GWAS). A total of 155, 91, and 48 accessions from the United States Department of Agriculture (USDA) soybean germplasm collection from MG 0 and I were screened with a single isolate each of , , and , respectively, using the inoculum layer inoculation method in the greenhouse. The disease severity was assessed 21 days postinoculation and analyzed using nonparametric statistics to determine the relative treatment effects (RTEs). Eleven and seven accessions showed significantly lower RTEs when inoculated with and , respectively, compared with the susceptible cultivar 'Williams 82'. One accession was significantly less susceptible to both and . The GWAS conducted with 41,985 single-nucleotide markers identified one QTL associated with resistance to both and , as well as another QTL for resistance to both and . However, no common QTLs were identified for the four pathogens. The USDA accessions and QTLs identified in this study can be utilized to selectively breed resistance to multiple species of .[Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.