籼稻稻米品质性状遗传特点新解析

Novel Anlysis on Genetic Characters of Quality Traits in Indica Rice

本研究以丝苗型籼稻优质品种七丝占与抗稻瘟病品种外选35为亲本杂交,从F2代开始采用单粒传法构建了含543个株系的重组近交系(RILs)群体,并分析了群体中各株系包括整精米率、垩白粒率、垩白大小、垩白度、透明度、直链淀粉含量和胶稠度共7个稻米品质性状的基因分布频率和性状相关性。根据实验数据分析结果,我们推测RILs群体中7个性状都符合2个基因控制的遗传模式,并存在4类遗传频率分布:(Ⅰ)两亲本间有极端差异的2个等位基因分离,其中一个亲本含2个增效等位基因,另1个亲本为2个减效等位基因的杂交类型,直链淀粉含量性状属于该分布类型;(Ⅱ)2个亲本各有1个增效等位基因,表现为2个中等值材料的杂交类型,包括的性状类型为透明度和垩白大小;(Ⅲ)两个较低值亲本杂交类型,实际上2个亲本共同有1个减效等位基因,另有1个等位基因的差异,相应性状为垩白度和垩白粒率;(Ⅳ)2个较高值亲本杂交,2个亲本各有1个增效等位基因,另有1个等位基因的差异,包含性状为整精米率和胶稠度。各性状间相关系数分析表明,垩白粒率、垩白度、透明度和直链淀粉含量这4个性状存在2个等位基因的高度连锁(75%);垩白度与垩白粒率/垩白大小之间呈极显著正相关;直链淀粉含量与垩白粒率/垩白度之间呈极显著正相关;整精米率与垩白粒率/垩白度之间呈显著负相关;直链淀粉含量与胶稠度之间呈显著负相关;其它性状之间无显著相关性。

In this paper,we studided the distribution frequency and traits correlations of 7 rice quality traits,including head milled rice （HM）,chalky grain rate （CG）,chalk size （CS）,chalkiness degree （CD）,transparency of rice （TR）,amylose content （AC） and gel consistency （GC）,in a stable population of 543 recombination inbred lines （RILs） derived from the cross between indica rice Qisizhan with fine quality and Waixuan35 with blast resitant variety by single-seed-descent approach.According to the experimental data,we inferred that all the seven traits in RILs was gene controlling and belonged to the follwing 4 types of genetic frequency distributions：（Ⅰ） Both parents had two polar different and segregated alleles.among which maternal contained two positive alleles and paternal contained two negative alleles.AC was the typical one of it;（Ⅱ） Both parents had one positive allele and showed medium value phenotype,such as TR and CD;（Ⅲ） Both parents with low value phenotypes had a common negetive allele and one different allele.such as CD and CG;（Ⅳ） Both parents with high value phenotypes had a positive allele and one different allele,such as HR and GC.Two alleles with a high linkage value of 75% existed in the traits of CG,CD,TR and AC.Correlation coefficient analysis of the traits demonstrated that there were highly significant positive correlation between chalkiness degree and chalky grain rate/chalk size,highly significant positive correlation between amylose content and chalky grain rate/chalkiness degree,significant negative correlation between head milled rice and chalky grain rate/chalkiness degree,significant negative correlation between amylose content and gel consistency,no significant correlations between other traits.