【作者】 张亚东；

【导师】 汤述翥；

【作者基本信息】 扬州大学 ， 作物遗传与育种， 2003， 硕士

【摘要】 选用6个粒重及外观品质差异较大的粳稻品种（系），按完全双列杂交方式配制30个组合的杂种F₁及14个组合的F₂、1个组合的F₃家系和8个回交组合，考查亲本及各杂种后代的谷粒性状和加工、外观品质，研究粳稻粒重的遗传特性及其对品质的影响，结果如下： （1）穗上部籽粒粒重的变异度极显著小于中、下部；大粒品种的粒重变异受粒位的影响更大。因此，选取稻穗上部籽粒进行粒重遗传及相关研究最为合适。 （2）粒重及其长、宽、厚和加工、外观品质性状不受细胞质效应影响。 （3）粒重及其相关性状的杂种优势不明显；但组合间存有差异，当亲本粒重较轻时，F₁表现为正向部分优势，随着亲本粒重增加，F₁粒重的优势就会下降，并逐步转为负向部分优势。F₁粒重的表型值与亲本值存在一定程度的正相关，F₁粒重的优势指数与亲本值存在一定程度的负相关。 （4）谷粒性状的遗传力较高；粒重、粒厚主要受基因的加性效应控制，粒长、粒宽加性和显性效应都很重要，同时谷粒性状还受基因的上位性效应作用。 （5）粒重为质量-数量性状，由1对主基因和若干微基因控制，粒重越高，所带的微基因越多。主基因、微基因的显、隐性作用是不完全的。 （6）粒重与垩白性状呈显著正相关，粒宽对外观品质的影响最大；粒重超过32g以上，难以选育出符合国家标准的优质品系；优质粳稻品系的长／宽在2.01～2.30间比较适宜，粒重高，长／宽可提高至2.50；与优质亲本回交，有利于提高后代的选择效率。更多还原

【Abstract】 6 parents with major difference in gram weight and appearance quality were crossed in complete diallel design to study the genetic characters of grain weight and their correlation with appearance quality by way of analyzing grain traits of 30 F1 hybrids,14 F2 offsprings ,8 BC1F1 populations and 1 F3 line in japonica rice. The results were summarized as follows:(1) Grain weight of upper panicle has less variance and large grain than others, the effect of panicle position on variation of large grain variety was the biggest, selecting upper panicle is the most suitable.(2) No significant cytoplasmic effect on grain weight ,grain length, grain width, grain thickness and milling and appearance quality were tested.(3) There were no obvious heterosis in grain traits, but difference in combinations; When grain weight was lighter, the partly positive heterosis in F1 was manifested; with the increase of grain weight of parent, the heterosis decreased and gradually became partially negative heterosis. The positive correlations between expressional value of FI and parents value and the negative correlations between heterosis index of F1 and parents value were tested .(4) Grain characters has high heritabilities, the inheritance of grain weight and grain thickness were affected by additive gene effects.But additive and dominant gene effects had the same importance to grain length and grain width, all traits were affectedby some epistasis gene effects.(5) As a quantitative-quantitative trait, grain weight was controlled by 1 major gene and many minor genes, the higher grain weight was, the more minor genes. Dominant effect and recessive effect of major gene and minor genes were partially.(6) The significant positive correlations between grain weight and chalkiness was tested, the effect of grain width on appearance quality was the biggest; it was hard to select good appearance quality combination if grain weight exceed 32g; length/width ratio vary from 2.0 to 2.3 was suitable, if grain weight was larger ,the ratio may rise to 2.5; back-crossing with good quality parent was beneficial to improve the selective efficiency of offspring.更多还原