Harnessing genetic potentials for drought tolerance in wheat (Triticum aestivum L.) using tolerance indices and molecular markers

Drought is a major abiotic stressor in bread wheat that causes substantial yield losses globally. So, the investigation was conducted to find out drought tolerant genotypes in bread wheat using tolerance indices and molecular characterization at juvenile and grain filling stages. The experiments were conducted with 30 bread wheat genotypes and 54 simple sequence repeats (SSRs) alleles. The experiment was designed as randomized complete block design with three treatments viz. 0 M, 0.2 M, and 0.4 M mannitol solution at juvenile stages and split plot design with two treatments viz. control and drought at grain filling stages. The results revealed significant variations among the genotypes for traits under study in both stages. To reveal drought tolerance among the genotypes, six drought tolerance indices were employed. The genotype BARI Gom 30, BARI Gom 32, BARI Gom 22, BARI Gom 26, BARI Gom 27 and BWMRI-1 carried superior rank score and regarded as drought tolerant genotypes. For molecular genetic characterization, in total 54 alleles were detected using SSRs where number of alleles locus ranged from 4 to 9 with an average of 5.4. The 30 bread wheat genotypes grouped into two populations and four unique clusters. Finally, considering the morpho-physiological and molecular study, the genotypes BARI Gom 22, BARI Gom26, BARI Gom 30 and BARI Gom 32 are identified as drought tolerant genotypes and provide an undertaking aims for further research and breeding efforts to develop wheat varieties with tolerance against drought to subtropical environments.