Inheritance of resistance in four elite chickpea genotypes to Ascochyta blight

Ascochyta blight of chickpea caused by Ascochyta rabiei is a major constraint to chickpea yield in northern India. Though considerable efforts have been put to breed varieties with durable resistance, still this has not been fully achieved, probably due to the fact that genetic of host-plant resistance is not well understood. Four chickpea genotypes with consistent resistance over more than 10 years of testing were selected to study the inheritance of resistance and allelic behavior. F₂ plants of cross GL 94011 x C 214 segregated into resistant and susceptible plants to give a good fit to a ratio of 13:3. However, in rest of the genotypes GL 91037, GL 87045 and GL 84100 plants segregated into R and S plants to give a ratio of 9:7, indicating the resistance in these parents is governed by 2 dominant genes with complimentary gene actions. Genotype GL 91037 showed non-allelic relationship with PBG 1, thus can be considered as a good source of novel resistance for Ascochyta blight.