Polymorphism of GLI-A1 and GLI-D1 loci in Ukrainian and foreign bread wheat cultivars and lines

Aim. The aim of this work was to analyse the polymorphism of Gli-A1 and Gli-D1 loci of bread wheat storage proteins within a larger (inter)national collection of bread wheat cultivars and lines, using acid polyacrylamide gel electrophoresis (A-PAGE) and classical PCR with allele-specific markers. Furthermore, to determine the correspondence between allelic variants of gliadins and alleles detected by PCR for these loci. Methods. In total 145 bread wheat cultivars and lines of Ukrainian and foreign selection were studied. Storage proteins electrophoresis was carried out in acid PAGE (A-PAGE) according to the method of Poperelya (1989), and the allelic variants of gliadins were marked according to the international nomenclature and catalogue (Metakovsky et al, 2018). DNA was isolated using an adapted CTAB method, and PCR was performed with allele-specific primers for the Gli-A1 and Gli-D1 loci (Zhang et al, 2003). PCR amplified products were separated in a 7% polyacrylamide gel and stained with silver nitrate. Results. In the PCR analysis the frequencies of the Gli-A1.1 and Gli-A1.2 alleles among 91 modern Ukrainian bread wheat cultivars and lines was 0.80 and 0.20, respectively. In a collection of 48 foreign wheat cultivars and lines, these frequencies were 0.69 and 0.31, respectively. The frequencies of the Gli-D1.1 and Gli-D1.2 alleles in the Ukrainian collection were 0.31 and 0.69, respectively. The Gli-D1.1 allele prevailed in the foreign wheat cultivars tested, with a frequency of 0.64, the frequency of Gli-D1.2 was 0.31. Using A-PAGE, seven allelic variants of gliadins were found among Ukrainian cultivars, the most common being Gli-A1b and 12 allelic variants in the foreign wheat cultivars, the most common being Gli-A1a. Five different allelic variants of gliadins encoded at the Gli-D1 locus were found in the Ukrainian collection and eight in the foreign collection. Allelic variants of gliadins for six cultivars in the Ukrainian collection were undefined and marked as "possibly new". The most common allelic variant was Gli-D1b. It was determined that the Gli-A1.1 allele corresponded to the allelic variants Gli-A1a, Gli-A1ab, Gli-A1af, Gli-A1b, Gli-A1c, Gli-A1f, and Gli-A1l, and the Gli-A1.2 allele corresponded to Gli-A1o, Gli-A1r and Gli-A1x (Gli-A1x sensu Kozub et al, 2009). No correspondence was found between allelic variants of gliadins encoded at the Gli-D1 locus and Gli-D1.1 and Gli-D1.2 alleles. Conclusions. The most common allele of the Gli-A1 locus in a collection of 91 modern Ukrainian bread wheat cultivars and lines and that of 48 foreign cultivars was Gli-A1.1. For the Gli-D1 locus the Gli-D1.2 allele was most frequent in the Ukrainian cultivars, and Gli-D1.1 in the foreign cultivars. For the Gli-A1 locus, there was revealed correspondence between the allelic variants of gliadins encoded at the Gli-A1 locus and the Gli-A1.1/Gli-A1.2 alleles, but such a correspondence was not found for the Gli-D1 locus.