Genetic Dissection of Sorghum Dwarfism Through Systematic Screening of - Alleles in Chinese Germplasm.

Sorghum dwarfing genes (, , ) are crucial determinants of plant architecture and yield potential; however, their genetic characteristics and distribution patterns in Chinese sorghum landraces remain poorly understood. This study systematically analyzed their allelic distribution across 241 Chinese landrace accessions. Through rigorous PCR-based genotyping and detailed phenotypic characterization, we identified that only approximately 7% of the surveyed landraces carried natural dwarfing alleles, with mutations in the locus being the most frequently observed. Plant height statistics and genotyping of F2 plants, whose parents were 8R252 (tall accession) and 8R387 (dwarf accession), demonstrated that exerted the most pronounced effect on plant height reduction. Importantly, we discovered significant epistatic effects in double-recessive combinations, with the genotype showing particularly strong height reduction. These findings substantially advance our understanding of the genetic architecture underlying sorghum plant height variation and provide a robust scientific foundation for molecular breeding strategies aimed at optimizing lodging resistance and mechanical harvestability in sorghum improvement programs.