Heterosis and Genetic Studies on Yield and its Component Traits In Rice (Oryza sativa L.)

The nature and magnitude of heterosis and combining ability was studied in 24 F₁ rice hybrids involving four lines and six testers using line × tester analysis. Warangal Samba was best combiner for grain yield, among the testers Ramappa, Jagtial Samba and Kavya were judged as better parents for yield. Crosses viz., Samba Mahsuri x Jagtial Samba, Akshayadhan x JGL-11727, Surekha x Ramappa, Samba Mahsuri x Ramappa, Warangal Samba x Jagtial Samba, Warangal Samba x Ramappa and Akshayadhan x Early Samba having high sca values and per se performance for grain yield per plant, also recorded a high degree of relative heterosis. The maximum expression of (79.21 per cent), heterobeltiosis (70.59 per cent), and standard heterosis (88.76 per cent) for observed in cross Samba Mahsuri x Jagtial Samba. The crosses exhibiting good heterotic expression in F₁ are likely to give better segregants in later generations were additive gene effects were high.