Physiological and genetic characteristics of a salt-tolerant mutant line in soybean (Glycine max L.)

Abstract Soil salinity is a worldwide problem that reduces crop yields, but the development of salt-tolerant crops can help overcome this challenge. This study was conducted with the purpose of evaluating the physiological and genetic characteristics of a new salt-tolerant mutant KA-1285 developed using gamma-ray irradiation in soybean (Glycine max L.). The physiological responses of KA-1285 were compared with salt-sensitive and salt-tolerant genotypes after treatment with 150 mM NaCl for two weeks. In addition, a major salt tolerance quantitative trait locus (QTL) was identified on chromosome 3 in a study using the Daepung X KA-1285 169 F2:3 population, and a specific deletion was identified in Glyma03g171600 (Wm82.a2.v1.1) near the QTL region based on re-sequencing analysis. A kompetitive allele-specific PCR (KASP) marker was developed based on the deletion of Glyma03g171600 that distinguished the wild-type and mutant alleles. Through the analysis of gene expression patterns, it was confirmed that Glyma03g171700 (Wm82.a2.v1.1) is a major gene that controls salt tolerance functions in Glyma03g32900 (Wm82.a1.v1.1). These results suggest that the gamma-ray-induced mutant KA-1285 has the potential to be employed for the development of a salt-tolerant cultivar and provide useful information for genetic research related to salt tolerance in soybeans.