三系杂交水稻谷粒性状的遗传及相关分析

[目的]研究三系杂交稻谷的遗传动态，探索不育系和恢复系各自对杂交稻谷粒性状的影响。[方法]利用华中地区常用的4个三系不育系与27个恢复系（品种）为供试材料，组成4×27NCⅡ交配设计，对三系杂交稻谷粒性状进行了遗传及相关分析。[结果]谷粒长、粒宽、千粒重和长宽比等4个性状均为加性基因效应起主导作用；谷粒长、粒宽、千粒重和长宽比同时受到父母本的影响，但受父本的影响比受母本的影响大。谷粒长、粒宽、千粒重和长宽比都有很高的广义遗传力，分别为99.65％、98.31％、95.27％和98.81％。相关分析表明，粒长与千粒重和长宽比均达极显著正相关；千粒重与粒长和长宽比均达极显著正相关，与粒宽未达显著相关；粒宽与粒长和长宽比达极显著负相关。通径分析表明，粒长、粒宽和千粒重对长宽比的直接通径系数分别为0.6246、-0.5559和-0.0158。[结论]该研究系统分析了不育系和恢复系对杂交稻谷粒性状的影响，为杂交水稻高产、优质育种提供了理论基础。

Genetic and Correlation Analysis of Grain Characters in Three-line Hybrid Rice

[Objective] This study was to understand the genetic dynamics of three-line hybrid rice,and explore the respective effect of sterile line and restoring line on grain characters of hybrid rice.[Method] Four three-line sterile lines and 27 restoring lines(cultivars) commonly cultivated in Central China were regarded as experimental materials to conduct 4×27NC Ⅱ cross design,and the grain characters of three-line hybrid were analyzed at genetic and correlation levels.[Result] Four characters of grain length,grain width,1 000-grain weight and length-to-width ratio play the leading role in additive gene effect;these four characters were simultaneously influenced by male parent and female parent,but the effect from male parent was relatively larger.The grain length,grain width,1 000-grain weight and length-to-width ratio all have high broad heritabilities(respectively 99.65%,98.31%,95.27% and 98.81%).Correlation analysis showed that grain length was positively correlated with 1 000-grain weight and length-to-width ratio at extremely significant level;1 000-grain weight was positively correlated with grain length and length-to-width ratio at extremely significant level,and was insignificantly correlated with grain width;grain width was negatively correlated with grain length and length-to-width ratio at extremely significant level.Path analysis showed that the direct path coefficients of grain length,grain width and 1 000-grain weight to length-to-width ratio were 0.624 6,-0.555 9 and-0.015 8,respectively.[Conclusion] This study systematically analyzed the effects of sterile line and restoring line on grain characters of hybrid rice,which provided theoretical basis for breeding high quality and yield hybrid rice.