Genetic basis of pod borer (Helicoverpa armigera) resistance and grain yield in desi and kabuli chickpea (Cicer arietinum L.) under unprotected conditions

Abstract

A series of half-diallel crosses involving early, medium and late maturity desi and kabuli type chickpea (Cicer arietinum L.) genotypes with stable resistance to Helicoverpa pod borer, along with the parents, were evaluated at two locations in India to understand the inheritance of pod borer resistance and grain yield. Inheritance of resistance to pod borer and grain yield was different in desi and kabuli types. In desi type chickpea, the additive component of genetic variance was important in early maturity and dominance component was predominant in medium maturity group, while in the late maturity group, additive as well as dominance components were equally important in the inheritance of pod borer resistance. Both dominant and recessive genes conferring pod borer resistance seemed equally frequent in the desi type parental lines of medium maturity group. However, dominant genes were in overall excess in the parents of early and late maturity groups. In the kabuli medium maturity group, parents appeared to be genetically similar, possibly due to dispersion of genes conferring pod borer resistance and susceptibility, while their F1s were significantly different for pod borer damage. The association of genes conferring pod borer resistance and susceptibility in the parents could be attributed to the similarity of parents as well as their F1s for pod borer damage in kabuli early and late maturity groups. Grain yield was predominantly under the control of dominant gene action irrespective of the maturity groups in desi chickpea. In all the maturity groups, dominant and recessive genes were in equal frequency among the desi parental lines. Dominant genes, which tend to increase or decrease grain yield are more or less present in equal frequency in parents of the early maturity group, while in medium and late maturity groups, they were comparatively in unequal frequency in desi type. Unlike in desi chickpea, differential patterns of genetic components were observed in kabuli chickpea. While the dominant genetic component was important in early and late maturity group, additive gene action was involved in the inheritance of grain yield in medium duration group in kabuli chickpea. The dominant and recessive genes controlling grain yield are asymmetrically distributed in early and medium maturity groups in kabuli chickpea. The implications of the inheritance pattern of pod borer resistance and grain yield are discussed in the context of strategies to enhance pod borer resistance and grain yield in desi and kabuli chickpea cultivars