Heterosis for Various Quatitative Traits in Rice (Oryza sativa L.)

Heterosis in rice was studied in a set of 4 lines and 10 testers with their 40 hybrids. The magnitude of heterosis varied from cross to cross for all the characters studied. The significant positive heterosis over better parent for grain yield per plant ranged from -28.71% to 39.18%. The cross combinations IR 28 x IET 20152 (39.18 %), followed by IR 28 x GR 103 (38.32%) and IR 28 x NVSR 20 (31.37%) exhibited significant positive heterosis over better parent for grain yield per plant. These superior crosses also exhibited somewhat significant and positive heterosis for panicles per plant, panicle length, grains per panicle, 1000 grain weight, protein content, amylose content and L/B ratio. Hybrid vigour of superior crosses may be exploited commercially after verifying the stability performance across the environments over years.