Inheritance of resistance to yellowberry in durum wheat

Resistance to grain yellowberry in durum wheat (Triticum durum Desf.) was investigated using generation mean analysis in four resistant or intermediate-resistant X susceptible crosses. Significant differences in resistance were observed between generations in all crosses. Generation mean analysis indicated a complex gene action controlling this trait, with additive, dominance and epistatic effects. Additive (d) components were positive in all crosses, suggesting that additive effects contributed more to resistance than to susceptibility. In contrast dominance (h) effects were negative in majority of crosses. The minimum number of genes controlling resistance was estimated at 1.41. Mid-parent heterosis ranged from 28.5 to 52.1 indicating dominance of resistance. Broad-sense heritability estimates ranged from 0.52 to 0.88, while narrow-sense heritability estimates ranged from 0 to 0.79. Estimates of genetic gain for resistance ranged from low to high. Estimates of broad and narrow sense heritabilities indicated that genetic effects were larger than environmental effects. Additive effects represented the largest components of genetic effects.