Why SR52 is such a great maize hybrid? I. Heterosis and generation mean analysis

摘要: SR52 is the first single cross maize hybrid to be commercialised in world and forms basis of breeding Zimbabwe Eastern Southern Africa region. Although such an exceptional hybrid, genetic its outstanding yield heterosis has never been explained. Therefore components associated traits were studied using a generation mean analysis. Parents (P1 P2), F1 segregating F2 backcross generations (BCP1 BCP2) evaluated. The experiment was laid out as randomised complete block design with two replications across sites South Africa, during 2012/2013 season. study confirms high levels exceeding 300 % for grain potential revealed significant lack fit additive–dominance model most secondary traits. Consequently, role epistasis investigated by partitioning it into additive × additive , additive × dominance dominance × gene effects. full confirmed presence highly (P ≤ 0.01) nature though negligible magnitude (<10 %). Both additive effects However, action contributed over 80 % potential. Additive played but minor (less than 20 %). We therefore concluded that displayed SR52.