Revealing allelic expressivity and distribution of genes for hybrid necrosis in north-west Himalayan diverse wheat (Triticum aestivumL.) gene pools

The investigation endeavored to study the distribution and allelic expressivity of hybrid necrosis genes (Ne1and Ne2) in 332 maternal lines comprising 274 triticale × wheat derived homozygous recombinants, 41 winter × spring and spring × spring wheat derived doubled haploid lines, 12 reconstituted wheat lines and 5 released bread wheat cultivars of north-west Himalayan regions utilizing Himalayan genetic resources. Hybridization was executed at Palampur and Lahaul and Spiti, India by crossing maternal parents with two known tester parents C306 (Ne1sNe1sne2ne2) and HD2380 (ne1ne1Ne2mNe2m) to generate F1hybrids. The necrotic lines were categorized into Ne1and Ne2-carriers based on the presence of necrosis genes in F1hybrids. Subsequent screening revealed the presence of 83 Ne2-carriers (25%) and 249 non-carrier genotypes (75%) in the present study. Eighty-three Ne2-carriers comprised 51 triticale × wheat derived homozygous recombinants (11 Ne2s, 6 Ne2ms, 26 Ne2m, 4 Ne2wmand 4 Ne2walleles), 22 winter × spring and spring × spring wheat derived doubled haploid lines (7 Ne2s, 12 Ne2mand 3 Ne2walleles), 9 reconstituted wheat lines (5 Ne2s, 2 Ne2mand 2 Ne2wmalleles) and 1 released variety (Ne2mallele) for necrosis and none of the lines possessed Ne1gene. Analysis of Ne2gene and their linkage properties with other paramount genes make Ne2-carriers superior source for emphasizing the genetic amelioration of wheat through selective hybridization.