Estimation of combining ability and heterosis for quantitative traits in maize (Zea mays L.) using diallel approach

Twenty eight hybrids obtained by crossing eight lines along with hybrid check were evaluated to study the hybrid vigor and combining ability in maize crop season rabi 2012–13 at Maize Research Station, Sardarkrushinagar Dantiwada Agricultural University, Bhiloda. The magnitude of heterosis was varied from character to character. The standard heterosis for number of ears per plant was registered for the hybrid I-07-11-3-3 × I-07-59-5 (28.57%). Low values of heterosis were observed for days to tasseling, days to silking and days to brown husk formation, while moderate values of heterosis were recorded for the other yield attributing traits. Maximum heterosis for ear eight was manifested by hybrid I-07-59-5(21.25%) followed by cross combinations I-07-11-3-3 x _07-65-18-3(21.16%) and I-07-6-4-4 x I-07-59-5(18.39). Parents P₁, P₄, P₅ and P₇ showed GCA in desirable direction for flowering and maturity traits. For yield and yield attributing traits the parents P₂, P₄, P₅ and P₇ reflectedpositiveand significantgeneralcombining effectsformostofthetraitsunderinvestigation. None of the hybrid found as good specific combiner for all the traits but cross combination I-07-9-3-1 x I-07-05-13-1 and I-07-11-3-3 x I-07-59-5 was found as good specific combiner for most of the maturity and yield attributing traits.