Genetic Dissection of Resistance to Pseudomonas amygdali pv. tabaci in Soybean [Glycine max (L.) Merr.] by Linkage Analysis

Wildfire, caused by Pseudomonas amygdali pv. tabaci (Pat), is a severe bacterial disease of soybean [Glycine max (L.) Merr.]. Enhancing resistance to wildfire is an important breeding goal, yet genetic studies remain limited. This study aimed to identify quantitative trait loci (QTL) associated with partial resistance to Pat using a Daepung × Taekwang recombinant inbred line (RIL) population. Sixty RILs were evaluated for resistance to the Pat isolate 'W14-M1'. Two QTL associated with resistance to Pat were identified on chromosomes 4 and 5, explaining 14.1% and 19.1% of the phenotypic variance, respectively. Daepung contributed the resistance alleles at both loci. The identified genomic regions overlapped with previously reported resistance QTL for bacterial, fungal, and nematode Pathogens. These findings indicate that Daepung is a valuable source of resistance to Pat, and the detected QTL may facilitate the development of molecular markers for pyramiding multiple disease resistance traits in soybean breeding program.