تجزيه ژنتيكي مقاومت به فوزاريوم سنبله گندم

Genetic Analysis of Resistance to fusarium Head Blight in Wheat

Seven wheat lines with different degrees of resistance to scab and their 21 F2 populations were evaluated for Fusarium head blight (FHB) resistance in a replicated field experiments at Golestan province, Iran, in 2001. After artificial inoculation, disease severity, disease incidence, area under disease progress curve (AUDPC) for disease incidence and disease severity and FHB index were measured. General combining ability (GCA) and specific combining ability (SCA) effects were calculated using Griffinʹs method. Mean squares for GCA and SCA were significant for all characters. Both combining ability analyses and estimates of genetic components indicated that additive and nonadditive gene actions were involved in the genetic variability of the characters examined. However, additive effects appeared to be more important than dominance effects. Significant negative (desirable) GCA effects for Sumai#3 and Wangshui-bai and significant positive effects for Shiroodi, Falat and Tajan, were observed in relation to the traits under study. Significant negative (desirable) SCA effects were detected for all chracters in two crosses (Falat * Sumai#3 and Shiroodi * Wangshui-bai ). Broad-sense heritability estimates were high (0.81-0.89), whereas narrow-sense heritability estimates were almost intermediate (0.39-0.51) for the indices measured in the experiment. This indicates that selection for the FHB resistance should be possible using these indices specially the disease incidence which is an easy character to be measured in the field.