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Response of six wheat varieties and their Fl progenies, produced through diallel crossing, to sunn pest were evaluated under field conditions in karaj using
RCBD with three replications. Since analysis of variance indicated significant
difference among genotypes, diallele analysis using Griffing and Hayman procedures
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were performed. Combining ability analysis of variance indicated significant
difference in ear damage for both general and specific combining ability effects. Falat and Bezostayax Golestan (with lowest GCA and SCA effects) were the best cultivar
and hybrid for increasing resistance to ear damage, respectively. For grain injury, only SCA effects were significant and GolestanxGafgaz cross with lowest SCA effect
was observed as the best hybrid for increasing resistance to grain injury. Hayman's diallel analysis indicated that non-additive gene effects were higher than the additive
part for resistance to ear damage while for resistance to grain injury, additive and non-additive effects were equal. Non-additive gene effect for ear damage and grain
injury were of over-dominance and complete dominance type, respectively. Broad and narrow sense heritability estimated for resistance to ear damage were 92.3 and
44.4 percent, and these for grain injury were 63.7 and 23 percent respectively. Grain injury was not significantly correlated to biochemical and morphological factors
measured in non-affected grain. Qualitative traits such as gluten quality were adversly and significantly affected by nymphs feeding.