Combining ability and heterosis among elite bacterial blight resistant lines in rice (Oryza sativa L.)

摘要

Combining ability analysis for yield and other agronomic traits were made in F_1 and F_2 diallel of seven varieties resistant to bacterial blight of rice revealed highly significant combining ability variances for plant height, panicle number/plant, panicle length, spikelet number panicle, grain number panicle, total dry matter, harvest index and grain yield plant indicating importance of non-additive gene action in their expression. The parent BJ 1 was the best combiner for most characters includingyield. Parent BBL 307 and C 702015 were good combiners for days to flowering and spikelet and grain number/panicle. SCA effects indicted significant sea x generation interaction. The crosses C 702015 /IR 50400, BBL 307/BJ1, BBL180/C 702015 and RP 633 /RP 2151 recorded the highest sea effects for yield. Maximum value for relative and heterobeltiosis were 67.14 and 52.35 per cent, respectively. The above four crosses alongwith BBL 307 / BJ 1, BBL 307 / C 702015 and BBL 307 / IR 50400, BBL 180 / C 702015, C 702015 / IR 50400 and RP 633 / RP 2151 were identified as the best hybrids based on superior per se performance, heterosis and specific combining ability effects for exploiation.