Journal of Agronomy and Field Innovations

Sorghum bicolor is an important cereal crop with a high potential for climate-smart agriculture in dry and semi-dry climates across the planet. This research details a Genome-Wide Association Study (GWAS) aimed at revealing the genetic factors responsible for drought resistance and grain production in sorghum. A total of 284 sorghum variants from different plant populations around the world were assessed using 125,000 genome-wide SNPs and evaluated for drought tolerance and grain productivity under different conditions in three locations during two growing seasons. The results of analyzing the genetic structure indicated the presence of four bright genetic groups with a great level of genetic diversity (mean PIC = 0.31). GWAS revealed 47 SNP associations at P < 1 x 10^-6 across 37 locations on the genome. Of these associations, 18 showed pleotropic character indicating that drought resistance and grain yield are under the influence of common genetic factors. The most associations were placed on chromosome 3 (with 8 associations), among which a gene correlating with SbDREB2A, the gene responsible for drought tolerance was found. The other significant loci include genes involved in the production of osmolytes such as SbProDH, aquaporin-mediated translocation of water (for example, SbPIP2-1), and signaling via abscisic acid (like SbABA2). Using available genomic resources from sorghum and QTL mapping data, 23 loci have been validated, with 12 being novel. This research presents new genomic resources and genes that aid in the accomplishment of the breeding of drought-resistant sorghum varieties with high yields and growth potential in harsh agricultural conditions. The mentioned loci are good targets for selecting genes that would improve the climate adaptability of sorghum and species closely related to it.