Selection of parents and prediction of heterosis in rice

An experiment was conducted to study the relationships between parental lines and heterosis by using 29 hybrids, 26 restorers and 3 maintainers. The results revealed that the reproductive phase initiation(RI) was invariably early in hybrids. The reproductive phase duration (RD) was invariably longer in hybrids which showed better parent heterosis. The distribution of parents based on DMRT followed by joint scoring over seven traits indicated most parents in Medium group which contained 87% of the promising restores (whose hybrid combinations showed better parent heterosis for yield). The relationship between parental lines showed that heterosis resulted from the complementation of traits. A thorough evaluation of restorers for various traits is necessary to choose appropriate ones and the restorers for making heterotic combinations should be drawn preferably from Medium group.