Combining ability for polygenic traits in medium maturing exotic maize (Zeamays L.) under rainfed environment

Combining ability analysis using line x tester design was conducted in yellow seed colour medium maturity exotic maize (Zea mays L.) inbred lines for yield and yield contributing characters. There was significant variance for treatments for all the traits studied and alsD there was greater contribution of lines towards σ²gca for all the traits. Inbred lines viz., 90[SPMATC4/P500 (SELY)]#-B-35-1-B-B-B, P45c6HC82-4-1-2-B-1-3-4-1-3-B-B-B-B-B-B and POB.33c3-181-4-2-4-B-BB-B. (except for kernel rows per ear) were good general combiners for all the traits. Tester CM-111 was good general combiner for grain yield per plant, ear length and kernels per row. Among the selected hybrids conventional single cross hybrid 90[SPMATC4/P500 (SELY)]#-B-35-1-B-B-B x CM-111 exhibited highest-magnitude of positive significant sca effect with highest magnitude of significant positive economic heterosis for grain yield per plant The single cross 90[SPMATC4/P500(SELY)#-B-35-1-B-B-B x CM-111 was a good specific combjnation for grain yield per plant, ear girth and kernel rows per ear, 90[SPMATC4/P500(SELY)#-B-35-1-B-B-B x CM-116 was a good specific combination for kernels per row and single cross POB.33c3-181-4-2-4-B-B-B-B x CM-111 was a good specific combination for ear length and 100 kernel weight.