VALIDATION OF KASP MARKERS FOR ADAPTATION AND YIELD-RELATED TRAITS IN SPRING BREAD WHEAT BREEDING LINES OF KAZAKHSTAN

The validation of molecular markers under target environmental conditions is essential for the effective implementation of marker-assisted selection in wheat breeding. This study aimed to assess the genetic diversity of spring bread wheat germplasm from Kazakhstan, validate KASP markers associated with adaptation and yield-related traits, and identify favorable alleles for breeding applications. A total of 107 spring bread wheat genotypes originating from five breeding organizations were evaluated in four contrasting environments of Kazakhstan and genotyped using 43 KASP markers developed from previous genome-wide association studies (GWAS) and quantitative trait locus (QTL) mapping studies. Of the analyzed markers, 33 were polymorphic and successfully differentiated the studied germplasm. Genetic diversity analysis revealed moderate variation among breeding collections, with the highest level of polymorphism observed in the lines from Karabalyk Agricultural Experimental Station collection (100%). Principal coordinate analysis demonstrated clear genetic differentiation among breeding programs. Association analysis identified numerous significant marker–trait relationships across environments, with the largest number detected in North Kazakhstan. Five markers (ipbb_ta_152, ipbb_ta_219, ipbb_ta_223, ipbb_ta_183, and ipbb_ta_162) showed stable associations with adaptation- and yield-related traits across all testing locations. Evaluation of allelic effects revealed that marker ipbb_ta_162 had the strongest positive influence on grain yield, particularly under North Kazakhstan conditions, whereas ipbb_ta_183 exhibited the most stable favorable allele across environments. The results confirm the usefulness of KASP markers for marker-assisted selection and provide valuable molecular tools for the development of high-yielding and environmentally adapted wheat cultivars in Kazakhstan.