Estimates of Combining Ability and Gene Action in Groundnut (Arachishypogeae L.) for Resistance to Aphis (Aphis craccivora Koch)

Abstract

Nine groundnut genotypes, consisting of three male testers and six female lines were crossed in a line x tester mating design to develop 18 hybrids in 2010. The resultant hybrids, parents and three checks were evaluated using a completely randomize design in the screen house of Institute for Agricultural Research (IAR) located at Samaru (11^o11'N, 7^o38' E) in 2012 to obtain information on combining ability and gene action for resistance to aphid and other quantitative traits in groundnut. Results of the combining ability analysis revealed that both additive and non-additive gene actions were responsible for the control of the traits studied. However, the values of dominance genetic variance were greater than additive genetic variance for all traits which depicts the importance of non-additive gene action for controlling these traits.Narrow sense heritability was low for all the traits studied except shelling percentage (74.00%) which was high and ranged from 1.60% (number of pods per plant) to 74.00% (shelling percentage) also indicating non-additive gene action. Significant effects among female parents were observed in their General Combining Ability for pod yield, 100-seed weight, and number of pods per plant and among male parents for 100-seed weight and days to maturity. SCA effects for ICGX-SM 00020/5/P4/P1 x ICGV IS 07890, ICGX-SM 00017/5/P10/P1 x KWANKWASO and ICGX-SM 00017/5/P10/P1 x SAMNUT 14 revealed maximum positive result for pod weight. Lower negative SCA effects were observed among most of the hybrids for the characters studied.