Assessing genetic diversity and population structure of f4:f5 wheat genotypes using morphological and microsatellite markers under heat stress.

Diversity in the plant gene pool provides breeders with the opportunity to improve targeted traits. Enhancing the genetic background through the introgression of desired gene(s) is an effective strategy to combat stresses like heat. Two field experiments were carried out in 2019–20 and 2020–21 at the research fields of Genetics and Plant Breeding at Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh, to identify heat-tolerant wheat advance lines. In F4 generation, 60 advanced lines were selected from a pool of 160 line and in the F5 generation, 16 lines were selected from the previous selection. Analysis of variance revealed significant variation in both the F4 and F5 generations, with the F5 populations outperforming the check varieties. Grain weight demonstrated the highest heritability and genetic advance, while the plant yield exhibited moderate to high performance. Plant height had the most significant direct effect at the genotypic level, while grain weight had the highest impact at the phenotypic level. A total of 77 alleles were identified with an average of 4.53 alleles per locus. The genetic similarity analysis showed that Shatabdi and BARI Gom 25 had the highest similarity at 94%, followed by P3-18-10 with P3-11-3 at 90%, and P3-24-10 with P3-21-10 at 85%. The PCA, structural, and dendrogram analyses all indicated the same grouping of the selected lines. Therefore, selecting of these lines for the F₆ generation would enhance resilience against heat stress. [ABSTRACT FROM AUTHOR]