Abstract
Plant architecture and yield potential of wheat are significantly influenced by the plant height (PH). In the present study, a diversity panel consisting of 199 historical wheat cultivars of Pakistan was evaluated for PH in three environments, and a genome-wide association study (GWAS) was conducted to identify loci associated with reduced height. GWAS identified 19 loci that were associated with reduced height, out of which 12 loci were consistently identified in all environments. Allelic variations were analyzed in the diversity panel for five Rht genes including Rht-B1, Rht-D1, Rht13, Rht25, and Rht26 using diagnostic KASP markers. Furthermore, a KASP marker was developed for the identification of dwarfing allele Rht-B1p in wheat. Allelic frequency of the GA-insensitive dwarfing allele Rht-B1b was pre-dominant (69.6%) followed by the GA-sensitive Rht26 mutant allele (58.5%). Five dwarfing allele of Rht25 including Rht25c, Rht25d, and Rht25e were rarely present in the cultivars with a frequency of 1.5%, 1%, 0.5%, respectively. The use of alternate dwarfing alleles to reduce PH can increase the genetic base of wheat cultivars by removing selection pressure on Rht-B1b/Rht-D1b haplotype and can lead to the development of wheat cultivars with improved characteristics such as reduced lodging risk, increased resource allocation to grain, improved harvest efficiency, enhanced crop stability, and adaptability.