Studies On Combining Ability And Heritability Of Quality Characters In Early Hybrid Rice

In this study, 8 two line and three line sterile lines and 12 restorer lines were chosen and by way of incomplete dialect cross (NC II) design, the analysis on the combining ability, combining ability, genetic features of 12 quality characters of 20 parents and 96 combining and correlations among quality characters, which would have a more significance for early hybrid r ice breeding. The main results are as follows:1. There are very significant heredity differences in early hybrid rice quality characters. All parents' general combining ability (GCA) differences of early hybrid rice 12 quality characters are significant, except grain length (GL), milled rice ratio length to width (L/W), gelatinization temperature (GT) and protein content. Special combining ability (SCA) variance differences of parents are all significant, except gel consistency (GC) and chalky rice percentage. SCA differences of grain length (GL), L/W and protein content aren't great; SCA differences of chalky rice percentage and GC in early hybrid rice combining are great, and SCA differences of else quality characters are placed in the middle.2. The correlations of parents GCA in early hybrid rice quality characters with their phenotypic values are positive, except brown rice recovery, milled rice recovery and head rice recovery, but parents GCA in early hybrid rice quality characters are tied up with phenotypic values of F1. The correlations of SCA in early hybrid rice quality characters with their heterosis are significant positive.3.The sorts of rice quality characters bases on parents GCA and SCA variance, ZhulS and T98A are the best female parents; 316A, FengyuanA and Jin23A are better; 81 OS is good in head rice recovery and GC; SCA variance in brown rice recovery, milled rice recovery, head rice recovery and GC of XinxiangA; V20A isn't good in all quality characters. Zaohuilhao, Zao500, R402 and R404 are the best male parents; R28, D68, D34, To974 and To463 are better; R29 GC is good, else quality characters are not so good; Yo55 and R33 aren't good in all quality characters.4. Contrast to the high quality rice state standard, The ratios of reach the state standard in chalkiness score, chalky rice percentage, chalky area, GTand GC are low, but the ratios of reach the state standard in brown rice recovery, GL, W/L and protein content are high.5. The broad-sense heritability (hB2) of early hybrid rice quality characters are all high, except GL and L/W. But the narrow-sense heritability (hN2) are all low. GCA variances of brown rice recovery, GL, GC and protein content in total genotypic variances are all under 50%, and are all influenced more greatly by nonadditive effect. All female parent's GCA genotypic variances of early hybrid rice quality characters under male parents', except brown rice recovery and milled rice recovery.6. Genotypic coefficients are higher than correlative heritability of all quality characters, except milled rice recovery with L/W, chalky rice percentage, chalky area, chalkiness score, GT and amylose content. And the correlations among genotypic coefficients, genetic coefficients and correlative heritability are all very positive significant.7. Contributions of correlative genetic variance in early hybrid rice are all high, except GT to GL, chalky area. The follows indirect selections in early hybrid rice are all high: chalky area to chalky score, chalky rice percentage to chalky score, and brown rice recovery to milled rice recovery. Else two quality characters indirect selections are all low relatively.