水稻单穗质量和千粒质量的遗传分析

选择单穗质量和千粒质量较小的亲本CB1和CB7与较大的亲本CB4配制CB1×CB4和CB7×CB4组合,建立了相应的P1、F1、P2、B1、B2、F2群体,将其分为中、晚2个生产季节种植,考察了穗质量与粒质量性状.利用主基因+多基因混合遗传模型理论的Akaike信息准则(AIC)在B1、B2、F2代中鉴定影响数量性状的主基因存在与否,主基因存在时通过分离分析估计主基因和微效基因的遗传效应及所占总变异的分量.结果表明:单穗质量在所有B1、B2、F2中均符合1对主基因+多基因模型模式;主基因遗传率为58.06%～75.60%,多基因遗传率为5.03%～25.46%,总基因型遗传率为68.07%～96.68%;同一遗传群体不同种植季节下主基因遗传率无明显差异,但同一季节下CB7/CB4组合群体主基因遗传率均比CB1/CB4组合群体大,表明单穗质量遗传分析时应考虑到构建遗传群体的亲本选择问题;千粒质量在所有B1、B2、F2中均符合1对加性主基因+加-显性多基因模型模式,其中CB1/CB4组合群体中季主基因遗传率最高,为60.06%～69.38%;CB1/CB4组合群体中季多基因遗传率最小,为10.73%～23.21%;CB1/CB4组合群体中季总基因遗传率为71.48%～83.55%;CB1/CB4组合群体中季一阶参数d值最小,说明粒质量遗传研究时需要考虑构建遗传群体的亲本及种植季节的选择问题.

Genetic Analysis of Grain Mass Per Panicle and 1000-Grain Mass in Rice

The rice parents with lower grain mass per panicle and 1000-grain mass CB1,CB7 and the higher parent CB4 were chosen to construct the combines CB1×CB4 and CB7×CB4;also the corresponding P1,F1,P2,B1,B2,F2 populations were established and planted as middle and late two planting seasons and the mass per panicle and 1000-grain mass traits were checked,respectively.The Akaike’s information criterion(AIC) of the major genes plus polygenes mixed inheritance model was used to identify the existence of major genes affecting quantitative traits in B1,B2,F2 populations,and when the major genes existed,the genetic effects of the major genes and polygenes and their genetic variance were estimated through segregation analysis.The results showed: One major genes plus polygenes was the most fitted genetic model for grain mass per panicle in the all B1,B2,F2 populations.The heritability values of the major genes varied from 58.06% to 75.60% and those of polygenes varied from 5.03% to 25.46%,and the total heritability values were from 68.07% to 96.68%.The heritability values of the same genetic population under the different planting seasons showed little difference,while those of population of combination of CB7/CB4 were higher than those of population of combination CB1/CB4 of the same planting season.The findings suggested that parents selection constructing the genetic population should be considered when analyzing the heredity of the grain mass per panicle trait.One additive major gene plus additive-dominance polygenes was the most fitted genetic model for 1000-grain mass in the all B1,B2,F2 populations.The heritability values of the major genes of population of combination CB1/CB4 as middle season planting were the highest in the two genetic populations of the two planting seasons and varied from 60.06% to 69.38%.While the polygenes heritability values of population of combination CB1/CB4 as middle season planting were the lowest and varied from 10.70% to 23.21%.The total genes heritability values of population of combination CB1/CB4 as middle season planting was varied from 71.48% to 83.55%.The first order parameter d value of population of combination CB1/CB4 as middle season planting was the lowest in the two genetic populations of the two planting seasons,which suggested that parents selection constructing the genetic population should be considered when analyzing genetic of the grain mass trait.