Quantitative trait loci mapping for salt tolerance-related traits during the germination stage of wheat

Soil salinization is a type of abiotic stress that affects the growth and development of wheat. To explore the QTLs related to salt tolerance during the germination stage of wheat and to reveal the mechanisms of salt tolerance, this study subjected 196 wheat varieties (lines) from North China, East China, and Central China to salt stress during the germination stage. Principal component analysis was employed for a comprehensive evaluation of salt tolerance. Based on the comprehensive evaluation D value, the salt tolerance of the research materials was classified into five levels, from which 64 materials exhibiting salt tolerance or higher were selected. Further, a genome-wide association analysis was conducted on the phenotypic traits and D values of wheat under different treatments during the germination stage using sequencing data from a 16Kb SNP chip. A total of 108 QTLs significantly associated with salt tolerance during the germination stage were identified, distributed across 15 chromosomes, excluding 1A, 1D, 4A, 5B, 6B, and 7B. Individual significant SNPs could explain 8.03% to 22.62% of the phenotypic variation. Additionally, 11 candidate genes potentially related to the salt response in wheat were predicted. This study provides a theoretical basis for the cloning of salt tolerance-related genes and the breeding of salt-tolerant wheat varieties.