Variation of high molecular weight glutenin subunits in two neglected tetraploid wheat subspecies

The genetic diversity of 140 accessions of Triticum turgidum ssp. carthlicum Nevski em. A. Löve & D. Löve and 159 accessions of T. turgidum ssp. polonicum L. em. Thell. was evaluated by the analysis of HMW glutenin subunits. Seven allelic variants were found among the carthlicum accessions: three at the Glu-A1 locus (two of them were novel alleles) and four at the Glu-B1 locus (one of them novel). More variability was found among the polonicum accessions with 16 allelic variants: six at the Glu-A1 locus (three of them novel), and ten at the Glu-B1 locus (five of them novel). Totally, ten new alleles were found, one of which appeared in both subspecies. Out of 19 different combinations of alleles detected in both subspecies, 14 were novel. Based on the available passport data, the carthlicum accessions could be separated by origin into 18 groups, and the polonicum accessions into 33 such groups. The genetic diversity was lower among the carthlicum (Ht = 0.174) than among the polonicum accessions (Ht = 0.562). In both subspecies, most diversity was present between groups differing in origin, whereas diversity within the groups was very low. The detected variability offers possibilities for the improvement of bread making quality in durum wheat through introduction of newly detected alleles and for the broadening of genetic diversity in this wheat species.