Genetic And Correlative Analysis Among Kernel Gravity And Ear-kernel Characters Of Hybrid Rice

Enhancing the grain weight is an important way to enhancing the yield, which can be improved by enhancing specific gravity with the same kernel size or smaller. According to the shortcomings of former researches, a6×5diallel cross of rice (Oryza.saliva L.) was conducted for genetic and correlative analysis among kernel gravity and ear-kernel characters. The result showed:1. The general performance of ear-kernel characters of hybrid rice.(1)The variation coefficient of were kernel gravity(KG), grain plumpness(GP), kernel density(KD), grain volume(GV),1000-grain weight(TGW), seed setting rate(SSR),grain weight per plant(GWP), panicles per plant(PP) and grains per spike(GS) were5.4%,7.0%,7.7%,23.6%,24.3%,24.6%.26.8%,38.5%and51.5%from lowest to highest, respectively.(2)The variation range of KG was1.151-1.187among different parent population. TGW can be increased by0.729-0.907g with a given grain volume.2. The relationship between ear and kernel characters of hybrid combinations.(1) Different correlations were found among ear-kernel characters. A trade-off relationship was also found existing between KG, SSR and GV. Optimizing of the other characters, based on a high level of panicle number, would be benefit for yield increasing steadily for its low correlations between other characters. KG showed a significant positive effect on yield.(2) Signillcant negative correlations were found between KG and PP, SSR, GP, GV. KD while positive between KG and GS, TGW, without the affection of GV a significant positive partial correlation were found between KG and TGW.(3) Productive panicles, GS, SSR, and TGW had higher positive effects on yield with positive effects of KG on most of the other yield components, especially on GS.3. Genetic characteristics of kernel weight on hybrid combinations.The variance of KG, BD and TGW between different combinations and parent population showed a significant difference. The general combining ability (GCA) of parents and specific combining ability (SCA) of hybrid combinations are the main factors of kernel weight, and GCA is more important. The result of cross design with KG、BD and TGW were almost the same.So, the strategy of gravity selection for hybrid rice breeding showed a great potential and feasibility. Appropriate strategy was given in this study.