Combination of Vrn Alleles Assists in Optimising the Vernalization Requirement in Barley (Hordeum vulgare L.)

Vernalization genes (Vrn) play a key role in plant adaptation to various geographic locations and their allelic diversity can have fundamental importance for breeding programs. In the current study, 340 barley genotypes were studied, including germplasm accessions and advanced breeding lines. For phenotype evaluation in South-Eastern Kazakhstan, the transition of barley plants from vegetative to reproductive stages was estimated in field trials with spring- and winter-sown seeds. For molecular analysis, 10 previously described molecular markers were studied in three barley vernalization loci: Vrn-H1, Vrn-H2 and Vrn-H3. The comparison between molecular results and phenotypes for plant development confirmed 211 spring genotypes, 56 winter and 28 facultative. Vrn-H1 haplotypes 1A and recessive allele vrn-H3 were in the majority. Best spring and winter high-yielding advanced breeding lines were identified. Based on Vrn allele combination, a breeding line 76/13-4 with facultative type development showed superior results in both winter and spring sowings, presenting a new prospective barley cultivar that can be grown equally either in spring or winter sowing conditions. The presented results can be used for barley marker-assisted selection predicting crosses with favourable combinations of Vrn alleles for prospective breeding line development.