Evaluation of infection type and inheritance of resistance to powdery mildew in two crosses in barley

Abstract In order to evaluate the gene number, gene effect and heritability to powdery mildew in barley Two resistant cultivars were crossed with a susceptible cultivar. In a field study, the parents (P1, P2) and the generations (F1, F2 and F3) of two crosses were evaluated in a randomized complete block design with three replications. The infection type of flag leaf and the whole plant was assessed in booting stage using Saari, E.E., and Prescott method. The Scaling test indicated that the effects of additive, dominant and epistatic, and mainly additive × additive effect has an important role in controlling to resistance to powdery mildew in barley. In the cross Hebe × Arigashar, using 2  test for segregating F2 generation , it was determined that duplicate dominant epistasis shows 15:1 ratio. Also in the cross Igri × Arigashar, using 2  test the F2 generation, it was determined that the distribution of 2 F generation of threefold dominant epistatic shows 35:1 ratio. general heritability of infection type in two crosses were estimated respectively 68% and 88%. Depending on traits and crosses, the gene number ranged from 1-2 and 3-6.