GENOME-WIDE ASSOCIATION STUDY OF YUNNAN-SPECIFIC WHEAT VARIETIES UNDER CONDITIONS OF DROUGHT STRESS

Drought is associated with serious declines in crop yield. In this study, we investigated and analyzed the effect of drought on wheat yields. We considered 263,742 single nucleotide polymorphisms (SNPs) obtained from genotyping-by-sequencing (GBS) and a genome-wide association study (GWAS) using PH (plant height), DTM (days to maturity), TGW (thousand grain weight), NGS (number of grains per spike), EL (ear length), FLL (flag leaf length), and FLW (flag leaf width) as indices. We identified 60 significant SNPs associated with EL, 41 with PH, 24 with DTM, 17 with FLL, 5 each with NGS and FLW, and 3 with TGW. We further identified 77 putative and potential genes within 100 kb from the major SNPs. We found that these genes encode transcription factors and hormones and are involved in enzyme activity, transmembrane transport, signal transduction, epidermal wax synthesis, metabolism, growth and development, pigment, stomata, root hairs, and stress tolerance. Collectively, our results provide valuable insights into the genetic basis of drought resistance in bread wheat. Further studies that predict candidate genes will help interpret the drought resistance mechanism of wheat, and aid the selection and breeding of drought-resistant wheat varieties suitable for different environmental conditions.