Development and investigation of common wheat lines of winter cultivar Bezostaya 1 with combinations of dominant alleles of VRN-1 loci

Abstract

VRNgenes, determining wheat sensitivity to vernalization, are the main genetic system that defnes the duration of the entire growing period and the durations of the main organogenesis phases. To date, several alleles have been described forVRN-1loci, and allele­specifc primers have been developed that allow rapid identifcation of allelic spectra in common wheat varieties and lines. The unequal influence of different alleles ofVRN-1loci on the duration of the growing period has also been shown; however, there is little information on the effect of the combination of different alleles on heading time. In developing genotypes having different alleles of dominantVRNgenes on the base of the same genetic background, it is necessary to study the genetic effects ofVRNgenes on the duration of the growing season and the individual developmental phases, as well as on productivity. Most varieties presently grown in Russia carry the dominant alleles of twoVRN-1genes:Vrn-A1aandVrn-B1aorVrn-B1c; thus, the task was to create lines combining the dominant alleles ofVrn-A1awithVrn-B1aandVrn-B1cagainst the genetic background of the winter variety Bezostaya 1 (Bez1Vrn-A1a/Vrn-B1aand Bez1Vrn-A1a/Vrn-B1c). Homozygous plants were isolated in the F2 generation by using known allele­specifc primers for theVrn-A1andVrn-B1loci. The durations of the tillering–frst node period, which is the key stage determining growing duration, and the period from shoots to heading were signifcantly reduced in lines with a combination of two dominant alleles ofVRN-1loci compared to isogenic lines of Bezostaya 1 with the dominant allelesVrn-B1aandVrn-B1c. The duration of these developmental phases also decreased in the obtained lines as compared to the isogenic line containing the dominantVrn-A1aallele, but the differences were not signifcant. No substantial differences were found in the duration of other growing phases in lines with two dominant alleles of theVRN-1loci as compared to isogenic lines of Bezostaya 1.