SELECTION OF DROUGHT TOLERANT PARENTAL LINES OF WHEAT THROUGH MORPHO-MOLECULAR DIVERSITY AND MULTI-TRAIT GENOTYPE-IDEOTYPE DISTANCE INDEX

Abstract

Drought is a major abiotic stress that significantly reduces wheat yield in the country. For this, the major aim of the study was to identify drought tolerant wheat genotypes from 100 diverse wheat genotypes. During the Rabi season of 2022–2023, the investigation was conducted at the experimental farm of Bangladesh Wheat and Maize Research Institute (BWMRI), Debiganj, Panchagarh and in the laboratory of the Department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur and BWMRI, Dinajpur, Bangladesh. This study used a split plot design with two replications to examine twelve morpho-physiological traits: plant height, number of tillers per plant, proline content, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, root volume, root length, root shoot ratio, relative water content, and excise leaf water loss. The analysis of variances revealed significant high heritability was recorded for proline content, shoot dry weight and root dry weight. A significant positive correlation between root dry weight and shoot dry weight was observed in both control and drought conditions. Based on the morphological diversity 1HZWYT-425, 1HZWYT-430 RAJ, 11SATYN-9425, Jamal-10032, 1HZWYT-422 RAJ, BAW-1397, Jamal 9046, SABGPYT-4104, Jamal-9006 were identified in cluster I and cluster III as similar genotypes at drought condition. Jamal-9046, SABGPYT-4104, 1HZWYT-425, SABGPYT-4110, 1HZWYT 430 RAJ, 11SATYN-9425, Jamal-10032, Jamal-9006, 1HZWYT-422 RAJ and BAW-1397 were identified as drought tolerant genotypes among 100 genotypes through assessment of multi-trait genotype ideotype index (MGIDI). Based on the molecular diversity five SSR markers viz. WMS0691, GWM513, GWM495, Barc20 and Tagwm1037 were evaluated in 96 wheat cultivars for molecular characterizations. All of the SSRs were polymorphic across the 96 genotypes. In total, 24 alleles were detected and the number of alleles per locus ranged from 2 to 7 with an average of 4.8 alleles per locus. The most polymorphic alleles (seven) were produced by the marker GWM495, followed by Tagwm1037 (6), GWM513 (5), and WMS0691 (4). In contrast, Barc20 markers yielded the fewest polymorphic bands per locus of two (2). The highest PIC value (0.84) was recorded for GWM495, and GWM513 recorded second highest (0.78) and lowest by Barc20 (0.46). The genotypes 1HZWYT-425, 1HZWYT-430 RAJ, 11SATYN-9425, Jamal 10032, 1HZWYT-422 RAJ, BAW-1397, Jamal-9046, SABGPYT-4104, and Jamal-9006 were found to be comparable in cluster III, V, and VI based on molecular diversity. Results obtained from the above two study suggested that the genotypes 1HZWYT-425, 1HZWYT-430 RAJ, Jamal-9046, 1HZWYT-422 RAJ and BAW-1397 should be important genetic materials for taking any future drought stress breeding programs in wheat.