Comparative Study of the Genetic Diversity of Hybrid Necrosis Genes in Modern Russian Cultivars of Spring Bread Wheat (Triticum aestivum L.)

The genetic diversity of hybrid necrosis genes in 113 modern Russian spring bread wheat cultivars was studied. The genomes of 83 (73.4%) cultivars were found to be noncarriers of hybrid necrosis genes (geno-type ne1ne1ne2ne2). The genomes of 14 cultivars (12.4%) carry the Ne1 gene (genotype Ne1Ne1ne2ne2), while 16 cultivars (14.2%) are Ne2 carriers (genotype ne1ne1Ne2Ne2). Among the Ne1 carriers, the w and m alleles were discovered, and among the Ne2 carriers, the w, m, ms and s alleles were found. It was suggested that greater diversity of the cultivars according to allele strength determines the advantage of the ne1ne1Ne2Ne2 genotype over the Ne1Ne1ne2ne2 genotype manifested by the fact that cultivars with the ne1ne1Ne2Ne2 genotype are allowed for commercial use in ten ecological regions, while those with the Ne1Ne1ne2ne genotype are allowed in seven. In different regions, the frequencies of Ne1 carriers vary from 4.8 to 20.7%, and those of Ne2-carriers vary from 6.0 to 66.7%. A certain stability for frequencies of noncarriers and Ne1 and Ne2 carriers was observed in different years. However, the number of cultivars of the ne1ne1Ne2Ne2 genotype tends to increase, although slightly, during breeding.