Molecular characterization of allelic variation at the VRN-1 and VRN-B3 loci controlling vernalization requirement in wheat genotypes based on polymorphism in the promoter and intron regions

Wheat, as a major crop in Iran and in the world, is considered an important crop for human consumption. Identification of allelic variations at loci that control vernalization requirements and cold tolerance, provides valuable information for determining adaptability of wheat genotypes to target environments. At molecular level, vernalization in wheat (Triticum aestivum L.) is determined mainly by three VRN-1, VRN-2 and VRN-3 loci. In hexaploid wheat, dominant alleles Vrn-A1, Vrn-B1 and Vrn-D1 are responsible for spring growth habit and recessive allels with epistatic interactions determine the winter growth habit. In this study, allelic variations among 50 wheat genotypes were studied using 9 primer pairs specific to VRN-1 and VRN-B3 loci. Dominant alleles at Vrn-B1,Vrn-D1 and Vrn-B3 loci were detected with the frequency of %58, %24 and %90, respectively. Recessive alleles vrn-B1, vrn-D1 and vrn-B3 had a frequency of %42, %76 and %10, respectively. At Vrn-A1 locus, different alleles were detected with the frequency of Vrn-A1c (58%), Vrn-A1b (26%), Vrn-A1a (14%) and vrn-A1 (2%). Our finding revealed a considerable level of variations at gene loci controlling vernalization and cold tolerance in dryland wheat genotypes. Data provided here may be used for producing new wheat cultivars adapted to the target environments.