Abstract
This study evaluated genetic variation in pre-harvest sprouting (PHS), seed dormancy, and yield-related traits in a diverse panel of 270 spring wheat accessions grown under two contrasting environments in Kazakhstan. Significant phenotypic variation was observed for agronomic traits, yield components, and PHS resistance, indicating substantial genetic diversity within the collection. Environmental conditions strongly influenced yield formation: spike productivity traits predominated in the Almaty region, whereas grain filling efficiency was the main determinant of yield in Kostanay. PHS exhibited wide variation among genotypes, with higher susceptibility observed in the northern environment. Nineteen genotypes showed stable resistance across both environments, representing valuable genetic resources for breeding. Notably, all resistant genotypes were characterized by red grain color, confirming the association between grain pigmentation and dormancy. Seed dormancy, assessed via germination index (GI), was significantly affected by environment and showed an inverse relationship with PHS. Correlation and multivariate analyses revealed weak negative relationships between PHS and yield components, suggesting that slightly reduce yield. Principal сomponent аnalysis (PCA) and genotype-by-environment interaction (GGE) biplot analyses identified stable and high-performing genotypes, including CAWBIN-179, CAWBIN222, and CAWBIN-385. These findings demonstrate the feasibility of combining high-yielding potential with PHS resistance in spring wheat breeding programs.