Deciphering the heat stress tolerance of advanced wheat lines based on morphogenetic and molecular analysis

Abstract Genetic diversity is crucial for plant breeding programs which provide necessary germplasm for selection and development of targeted traits. So, development and screening of suitable germplasm is vital. To enhance heat stress tolerance in wheat, an experiment was conducted using 60 F 6 wheat advanced lines (ALs), their parents, and check varieties at the Genetics and Plant Breeding Department, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh. The analysis of variance (ANOVA) elucidated substantial variation among the ALs and studied traits. Maximum grain yield plot −1 was recorded in AL 49 (603.8 g), AL 21 (612.4 g), AL 51 (580.9 g), and AL 20 (554.1 g). Phenotypic coefficients of variation were slightly higher than genotypic coefficients, indicating minimal environmental influence on the ALs. Grain filling duration, grains spike −1 , and plant height exhibited high heritability with moderate to high genetic advance as a percentage of the mean. These traits also showed strong positive genotypic and phenotypic interlink with yield. Path coefficient assessment further revealed that these traits had a high direct positive effect on yield. Among the microsatellite markers analysed, 14 markers were polymorphic, with an average PIC value of 0.67. Cluster analysis using phenotypic and molecular data grouped genotypes into three clusters, demonstrating substantial variation among the selected best 10 ALs. These ALs could serve as a potential germplasm in heat stress breeding or may be released as new varieties after multi‐location trials.