Clustering of Common Wheat Cultivars Based on Functional Markers Reflects Differentiation in Quantitative Traits in the Group of Poltava Cultivars - Cytology and Genetics

Abstract Among a vast number of polymorphisms in the wheat genome, of special interest are those that are markers for loci under selection. Such loci include storage protein loci, which directly determine the level of bread-making quality, and disease resistance genes. In this study we analyzed diversity of functional markers (seven storage protein loci and three disease resistance genes) in the group of East European winter common wheat genotypes (cultivars and lines of Poltava breeding). Using the UPGMA or NJ methods, the cultivars and lines were divided into two clusters differing in the Glu-1 quality score. The cultivars of cluster 1 with the lower mean Glu-1 quality score predominantly carried the combination of alleles Glu-B1c, Glu-D1a, and Gli-B1e, as well as the resistance allele of Lr34, whereas those of cluster 2 with the higher quality score mainly had the alleles Glu-B1u, Glu-D1d, and Gli-B1b. In the sample of Poltava cultivars, a high correlation between the Glu-1 quality score and the sedimentation value (0.84) was observed. On average for two years, the group of cultivars from cluster 1 showed higher grain protein content and some spike traits in comparison with the means of the sample from cluster 2. Significant associations of Lr34 alleles and alleles at some storage protein loci were revealed, in particular, the association of the resistance allele Lr34R and the allele Glu-D1a in both cultivar and line groups, indicating the adaptive value of such a combination for local soil and climate conditions.