水稻每穗粒数和二次枝梗数的遗传分析

Genetic Analysis of Grains and Secondary Branch Numbers per Panicle in Rice

选择每穗粒数和每穗二次枝梗数差异大的2个水稻亲本CB1(每穗粒数87.83粒,每穗二次枝梗数12.77个)、CB4(每穗粒数150.70粒,每穗二次枝梗数25.75个),配制CB1×CB4组合,建立了相应的P1、F1、P2、B1、B2、F2群体,将其分为中季和晚季两个生产季节种植,考查了每穗粒数和每穗二次枝梗数性状。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,每穗粒数在所有B1、B2、F2中均符合两对主基因+多基因模型模式,主基因遗传率为17.717%～63.562%,多基因遗传率为21.188%～59.449%,总基因型遗传率为76.029%～92.973%,每穗粒数遗传率受种植季别影响明显;每穗二次枝梗数在所有B1、B2、F2中均符合两对主基因+多基因模型模式,主基因遗传率为59.537%～71.787%,多基因遗传率为6.431%～23.870%,总基因型遗传率为78.121%～87.298%;每穗二次枝梗数遗传率受种植季别影响较小。

Two rice parents with great difference in grains and secondary branch numbers per panicle,CB1（87.83 grains and 12.77 secondary branch numbers per panicle）and CB4（150.70 grains and 25.75 secondary branch numbers per panicle）were chosen to construct the combines CB1×CB4,and the corresponding P1,F1,P2,B1,B2,F2 populations were established and planted as middle and late season rice.The two traits were checked.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 and F2 populations.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 that two major genes plus polygenes were the most fitted genetic model for grains per panicle in all B1,B2 and F2 populations.The heritability values of the grains per panicle of the major genes varied from 17.717% to 63.562%,and those of polygenes varied from 21.188% to 59.449%.The total heritability values ranged from 76.029% to 92.973%.The heredity of grains per panicle was affected by planting season obviously.Two major genes plus polygenes were the most fitted genetic model for secondary branch numbers per panicle in all B1,B2 and F2 populations.The heritability values of the secondary branch numbers per panicle of the major genes varied from 59.537% to 71.787%,and those of polygenes varied from 6.431% to 23.870%.The total heritability values were from 78.121% to 87.298%.The heredity of secondary branch numbers per panicle was hardly affected by planting season.