Studies On Genetic Effects Of Yield-related Characters In Hybrid Rice With The New Resources Of Cytoplasm Male Sterile

Diseutombing and utilizing the hybrid rice with new resources of CMS is one of the important breakthroughs at the present stage of super rice breeding.A new cytoplasm resource of hybrid rice (CMS-FA)which was bred by Fujian Agriculture and Forestry University is a new genetic system,the type of cytoplasm,the source of maintainer line,the relations of restoring and maintaining are different from WA and HL which belong to three-line hybrid rice,and also different from the sterile two-line hybrid rice respectively.Studying deeply on the genetic effects of this new type of hybrid rice is one of the main content to utilize the hybrid rice with new resources of CMS.Five CMS lines(Jinnong 1 A, Jinnong 2 A,Jinnong 3 A,923A,66A)and five restorer lines(Jinghui 1,Jinghui 2,Jinghui 3,Jinghui 4 and Jinghui 5)were selected from the new resources of hybrid rice cytoplasm(CMS-FA)genetic system and were designed by the way of incomplete diallel cross(5×5).The genetic effects,heterosis and genetic correlations of 10 yield-related characters which contain Plant height(PH),Panicles/plant (PP),Flag leaf length(FLL),Panicle length(PL),Spikelets/panicle(SP),Filled spikelets/panicle (FSP),Seed setting rate(SSR),1000-grain weight(TGW),Grain weight/plant(GWP)and Growth duration(GD)were analyzed systematically with a new additive dominant genetic model(AD model) and statistical analysis method of plant quantitative characters.The main results are as follows:1,The results of phenotypic analysis of yield-related characters of the hybrid rice with new resources showed that there were big diversities and great variations between parents and the F1 generation;the yield-related characters of the combinations have shown competitive advantage in different extent in relation to the CK Shanyou 63;Jinnong 2 A is the best,then the 66 A in the CMS lines,while Jinhui 5 is the best,then the Jinhui 3 and the Jinhui 4 in the restorer lines.2,The results of genetic effects analysis of yield-related characters of the hybrid rice with new resources showed that all the characters had additive effects and dominance effects expect the dominance effects of the FLL,PH,PL and GWP were the main additive genetic effects.GD,PP,FLL, SP,FSP,SSR,TGW were mainly controlled by dominance effects.The heritability in the narrow sense (h_N~2)of PP and PL was small,but the heritability in the broad sense(h_B~2)was big.The other 8 characters were all significant in h_N~2 and h_B~2.Jinnong 2A is the best CMS line and 66A is a very good parent of the high yielded combinations with new resources.Jinhui 3 is the best restorer line and Jinhui 5 is a very good parent of the high yielded combinations with new resources.Jinnong 2A in which all the combinations had prominent performance is a perfect parent.66 A xJinhui 5 has the character of earliness and high yield.3,The results of heterosis analysis of yield-related characters of the hybrid rice with new resources showed that there was dominance heterosis in the hybrid rice with new resources of CMS.More than half of the characters in hybrid combinations shown significant positive in population mean heterosis and transgressive heterosis.Heterosis of different characters showed different degrees of performance, and the GWP was the most.4,The results of genetic correlations analysis of yield-related characters of the hybrid rice with new resources showed that there was great effects of the yield-related characters.Additive correlation and dominant correlation were the mayor factors of genetic correlation among traits.The main significant additive effects of the yield-related characters were as follow:PP and SP,TGW,FLL;FSP and GD;SSR and PH,FLL;PH and GD;FLL and GD;PP and SP,FSP,PH,FLL,SP and TGW.The main significant dominance effects of the yield-related characters were as follow:PP and FSP,PL;SP and PR PL,TGW,FLL.