Combining Ability and Heterosis in Maize ( Zea mays L.)

Combining ability for growth parameter and yield components were evaluated in a 7×7 diallel fashion in maize at the research farm of Plant Breeding Division, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur during Rabi season 2013-14 to determine the general combining ability and specific combining ability of parents and the crosses. Significant general and specific combining ability variances were observed for some of the characters. The overall study of gca effects suggested that parent WL3 was significant for general combiner for yield, WL2 and WL3for earliness and WL1 for short stature. These parents could be used in future breeding programme to improve maize yield with desirable traits. The good combiner parents for different traits could be used in hybridization to improve yield as well as with desirable traits as donor parents for the accumulation of favorable genes. For yield improvement in maize both additive and non additive genes should be exploited through a suitable breeding method. However, the crosses WL1×WL6, WL1×WL7, WL4×WL5, WL6×WL7showed high sca effect for kernel yield. The significant positive sca of crosses could be used for commercial variety development after verifying them. The maximum heterosis was recorded in WL1×WL6 (15.60**%) when BHM 7 used as check and heterosis ranged from -56.59 to 15.60%. Only one hybrid WL2×WL7 recorded negative heterosis against BHM 7 for days to maturity.