Combining ability analysis and heterosis for yield and yield attributing traits in late maturing winter maize inbred lines (Zea mays L.). Frontiers in Crop Improvement, 7 (1): 42-51

Abstract

A study was conducted to assess the general and specific combining ability of the newly developed late maturing inbred lines.Twenty eightlate maturing inbred lines of winter season were crossed with two testers BML 6 and BML7 using line × tester mating design. The resulting 56 crosses along with 30 parents were evaluated during rabi 2015-16 and rabi 2016-17 in a randomized block design. ANOVA for combining ability revealed significant mean squares for GCA and SCA for all the traits studied which indicated the presence of both additive and non-additive gene action in the inheritance of these traits. The parent IMLSB-1299-5 followed by IMLSB-406-2 and IMLSB-334B-2 along with other four inbreds was identified as best combiner for grain yield. Out of the 28 lines, nine parents showed the positive significant GCA for days to anthesis and silking which can be utilized for development of medium to late hybrid varieties (Late varieties desirable in rabi maize).The crosses IMLSB-343-3× BML7 followed by IMLSB-428-2× BML-6 and IMLSB-156-2× BML-7 along with other six crosses showed positive significant SCA effects. Six hybrids viz. IMLSB-406-2 × BML-6, IMLSB-1299-5 × BML-7, IMLSB-1299-5 × BML-6, IMLSB-334B-2 × BML-7, IMLSB-814-2 × BML-6 and IMLSB-334B-2 × BML-6 showed positive and significant economic heterosis for grain yield over the standard commercial check. These promising cross combinations identified in this study could be utilized for future breeding work as well as for direct release after confirming the stability of their performances observed in the current study.