基于籼粳杂交重组自交系的水稻籽粒性状的遗传变异研究
Genetic Variation of Grain Traits Based on Indica-Japonica Cross of RILs in Rice (Oryza sativa)

为研究多环境条件下籽粒性状的遗传变异及性状间相关性，解析籽粒性状遗传规律。以细长型籼稻品种‘玉针香’和短圆型粳稻品种‘02428’为亲本构建的含192个株系的RIL（重组自交系）群体为研究材料，在4种环境下分别对籽粒相关的16个性状进行相关性分析和遗传变异解析。结果表明，两亲本的粒型、垩白性状存在显著差异，其中，‘玉针香’精米长宽比、垩白粒率和垩白度分别为4.03、1.00%和0.18%，‘02428’精米长宽比、垩白粒率和垩白度分别为 1.45、87.40%和52.21%。RIL群体各性状的平均值介于两亲本之间，分布频率呈趋于单峰的正态分布，符合数量性状遗传规律。多环境下变异分析表明，大部分籽粒性状受环境及环境与株系互作不同程度的影响；而谷粒面积、谷粒圆度2个性状受环境、环境与株系互作的影响均不显著。遗传群体各性状变异系数为6.34%～84.55%，广义遗传力为4.26%～70.67%。粒长、粒宽、垩白粒率、垩白度间呈明显互作关系。在RIL群体中筛选获得4个在穗部性状、粒质量和稻米外观品质等方面综合表现较为优良的株系，具有较高育种价值。说明：基于遗传背景明确的重组自交系群体，可解析籽粒性状的遗传变异规律，并有效创制优异育种材料。
Using the RIL population derived from the Indica-Japonica cross,the genetic variation and correlation of rice grain traitsand other traitswere analyzed under multiple environments,and to provide efficient genetic dissection of grain traits in rice.A RIL (Recombinant Inbred Line) population with 192 lines developed from a cross between indica ‘Yuzhenxiang’(long grain) and japonica cultivars ‘02428’(short grain),was used in this study.The correlation and genetic variation analysis were conducted about 16 kernel traits under four environments.The result showed that a significant difference for grain shape and chalkiness traits was observed between the two parents.The kernel length-to-width ratio of ‘Yuzhenxiang’ was 4.03,the chalky rice rate was 1.00%,and the chalkiness degree was 0.18%,whereas,the kernel length-to-width ratio of ‘02428’ was 1.45,the chalky rice rate and chalkiness degree were 87.40% and 52.21%,respectively.The average values of the traits in RIL were between the two parents; all traits tended to be normal distribution with a single peak,and met with quantitative genetics.Analysis of genetic variability under different environment indicated that grain traits were vary affected by environment and their interactions,but influence of environments to grain area and circularity was non-significant.The coefficient variation was 6.34% to 84.55%,and the generalized heritability ranged from 4.26% to 70.67%.There was a significant interrelate relationship among kernel length,kernel width,chalky rice rate and chalkiness degree.Fourrecombinant inbred lines with fine performance in panicle traits,grain mass,and appearance quality traits were obtainedfrom the RIL population,which possessed superior utilization value in breeding.In conclusion,this study dissected the genetic variation of grain-related traits in rice,and developed elite lines for breeding efficiently.