Genealogical and statistical analyses of the inheritance of gliadin-coding alleles in a model set of common wheat Triticum aestivum L. cultivars

Abstract

Allelic diversity of the gliadin-coding loci Gli-1 and Gli-2 was compared with the genealogical profiles of common wheat cultivars developed in Saratov. Allele tracking through their pedigrees and hierarchic cluster analysis associated 31 Gli alleles with groups of original ancestors. The cultivars Poltavka (12 alleles of six loci) and Selivanovskii Rusak (six alleles of six loci) were identified as sources of the majority of alleles. The results of the cluster analysis fully coincided with the results of allele tracking for alleles occurring at high frequencies. For rare alleles, the resolution of the cluster analysis was somewhat lower and depended on the similarity/distance measure. Thus, it proved possible to indirectly identify the donors of gene alleles by multidimensional statistics even when data on alleles identified in ancestors are unavailable. This approach to the analysis of inheritance has two limitations: detailed pedigree data should be known, and relatively high frequencies (no less than 15--20%) should be observed for the alleles in a sample under study. Cluster analysis was used to study the association of gliadin alleles with commercial quality classes. The most important gliadin-coding alleles, which mark strong cultivars, were identified. In the Saratov cultivars, such alleles include Gli-A1f, Gli-B1e, Gli-D1a, Gli-A2q, Gli-B2s, and Gli-D2e, which were inherited from the landrace Poltavka, and Gli-A1i, Gli-A2s, and Gli-B2q, which were inherited from the landrace Selivanovskii Rusak.