Genetic Analysis for Resistance to Sunn Pest (Eurygaster integriceps)

The objective of this experiment was to investigate inheritance and gene action for resistance to sunn pest (Eurygaster integriceps) and related traits in bread wheat including F1, F2 and backcross generations derived from a cross between line 15 as resistance and line 12 as susceptible parents. Parents along with F1, F2, BC1 and BC2 generations were evaluated in a randomized complete block design (RCBD) with three replications in the field of College of Agriculture and Natural Resources of University of Tehran in Karaj. Results of weighted variance analysis showed significant differences between 6 generations in all traits including weight of damaged seed, weight of total of seed in damaged spikes, weight of 50 damaged seed, weight of damaged spike and damaged seed percentage. Generation mean analysis by joint scale test showed that additive, dominance and epistasis components play a major role in resistance to sunn pest, but dominance component is more important. In damaged seed percentage as the most important trait to resistance, additive (d), dominance (h), and dominance×dominance (l) components were more important than other components. For damaged seed percentage, broad heritability and narrow heritability were relatively low and high, respectively. This result showed the more important role of dominance component.