Evaluation of allelic diversity of VRN1 and Ppd1 genes in different bread wheat cultivars

Major flowering time genes including vernalization and photoperiod response play a crucial role in the geographical and agronomical adaptations, and potential yield in cereals. Assessment and understanding of the distribution of allelic variations for vernalization and photoperiod genes is of special importance in wheat breeding programs and parental selection. Therefore, the objective of this study was to evaluate 38 bread wheat varieties for allelic variations at the VRN1 and Ppd1 loci, using functional molecular markers. In this study, the frequency of vrn-A1, Vrn-A1a and Vrn-A1b alleles at the Vrn-A1 locus were 57.9, 39.5 and 2.6 percent, respectively. At the Vrn-D1locus, vrn-D1 and Vrn-D1alleles had the frequency of 73.7 and 26.3 percent, respectively. At the Vrn-B1locus, the most frequent allele was Vrn-B1a with 44.7 percent, while the frequencies of Vrn-B1b, Vrn-B1c and vrn-B1 alleles were 21, 18.4 and 13.2 percent, respectively. Allelic variations at the Ppd-1 gene were also detected in the studied population. As allelic frequencies of Ppd-D1a and ppd-D1b at the Ppd-D1 locus were 71 and 29 percent, respectively. At the Ppd-B1 locus, 18 genotypes had Ppd-B1a allele, while 20 others showed ppd-B1b allele. In general, Ppd-D1 was the most frequent allele, followed by Vrn-A1a, Vrn-D1, Ppd-B1b and Vrn-B1a. These results indicate that the frequency of dominant allele at the VRN1 and Ppd1 genes was the highest. Therefore, according to these results, most genotypes can be considered as spring and insensitive to photoperiod.