Analysis on Combining Ability and Heritability of Major Agronomic Characters in Two line Indica Hybrid rice

elite parents of two line indica hybrid rice ,including five TGMS lines and nine restorer lines, were chosen to analyze the combining ability of 10 agronomic characters by way of p×q incomplete diallele cross (NCⅡ)design. The results showed that: a) Both general combining ability(gca) and specific combining ability(sca)were highly significant in all 10 characters; the additive variation was principal in plant height(PH), flag leaf length of main culm(FLLMC), 1 000 grain weight(TGW)and spikelets/panicle (SP) while the nonadditive variation was greater in grain weight/plant (GWP), days to heading (DH), seed setting rate (SSR) and panicles/plant (PP). b)All characters were influenced more greatly by restorer line than by TGMS line, but there was a relatively great effect of TGMS line on FLLMC, PL, TGW, DH and SP. c) The h 2 N was ordered from high to low as PH, TGW, FLLMC, SP, PL, filled spikelets/panicle(FSP), DH, PP, SSP and GWP.