Heterosis analysis for grain yield and yield component traits in rice (Oryza sativa L.)

An investigation in rice was undertaken to study the nature and magnitude of heterosis for yield and yield component traits involving ten high yielding lines and three superior grain quality testers and thirty hybrids were developed through line x tester mating design. Observations were recorded for days to 50% flowering, plant height, number of productive tillers per plant, panicle length, number of filled grains per panicle, hundred grain weight and single plant yield. Significant heterosis for grain yield and yield component traits were observed in most of the hybrids. Nine hybrids exhibited positive and significant heterosis over standard check but six crosses over better parent for single plant yield plant. Standard heterosis and heterobeltiosis for grain yield ranged from -15.64 to 20.04% and -23.75 to 15.50%, respectively. A total of four hybrids viz., ADT 39 x I.W.Ponni, ADT 43 x I.W. Ponni, ADT 49 x I.W. Ponni and CO (R) 50 x I.W. Ponni were recorded higher grain yield over both better parent and standard check and were identified as best hybrids for exploiting hybrid vigor. Most of the heterotic crosses for grain yield per plant were accompanied by heterosis for two or more component traits.