DIVERSITY OF GLIADIN-CODING LOCUS ALLELIC VARIANTS AND EVALUATION OF GENETIC SIMILARITY OF COMMON WHEAT-VARIETIES FROM DIFFERENT BREEDING COUNTERS

Alleles of Gliadin-coding loci (Gli) found in genotypes of eighty-six varieties of common wheat from England, Omsk, and Chelyabinsk were identified using polyacrylamide gel (pH 3. 1) electrophoresis of the wheat storage protein gliadin. The alleles most commonly found in each of these three varietal groups were identified. Alleles frequent in a particular region are assumed to be specific markers of those wheat plant traits that have particular importance in that region. Intrapopulation diversity ((mu +/- S(mu)), the portion of rare alleles (h +/- S(h)), the identity criterion (I), the genetic similarity (r), and the genetic distance (D) were calculated based on our analysis of Gli locus allele frequency. The least Gli locus diversity was in cultivars of Saratov origin (mu = 3.36 +/- 0.26) and the highest was in those from Omsk (mu = 6.31 +/- 0.35) and Chelyabinsk (mu = 6.15 +/- 0.33). In this case, the higher allelic diversity in Omsk cultivars as compared to Chelyabinsk cultivars was caused by a higher portion of rare alleles (h = 0.21 +/- 0.04 and h = 0.12 +/- 0.05, respectively). Interpopulation diversity was higher for the Gli-2 locus than for the Gli-1 locus. The genotypes of the common wheat cultivar groups studied differ from each other both at each of six Gli loci and, on the average, at all these loci. The cultivar groups from Omsk and Saratov were the most similar (r = 0.75, D = 0.28), and the cultivar groups from England and Saratov were the least similar (r = 0.13, D = 3.00). Generally, the cultivars from Omsk, Saratov, and Chelyabinsk are rather similar (on the average, r = 0.72) and differ significantly from the English varieties (r = 0.22). The relatively very high value of the D criterion obtained from analysis of the Gli loci may be explained by the significantly higher polymorphism of gliadin seed storage protein as compared with that of other enzymes used earlier in similar studies.