Heterosis for yield, its components and grain traits in rice (Oryza sativa L.)

Heterosis, heterobeltiosis and standard heterosis were estimated for grain yield, its attributes and other physical characters in 32 cross combinations generated through Line x Tester mating design. In general, the estimates of heterosis values were low for physical characters when compared to yield and yield components. Nine hybrids manifested positive and significant heterosis over midparent, better parent and standard check for grain yield plant-1, of which AD 95157 x IR 50, MDU 5 x IR 50, AD 95157 x ADT 43, MDU 5 x ADT 36, AD 95157 x ADT 36 and AD 95137 x ADT 36 were top rankers. On considering both yield and physical traits together the crosses MDU 5 x IR 50, MDU 5 x ADT 36, AD 95157 x ADT 36, AD 95157 x ADT 43, AD 95157 x IR 50 and AD 95137 x ADT 36 could be isolated for possessing desirable average heterosis, midparantal heterosis and standard heterosis for yield and grain traits.