水稻核不育系柱头性状的主基因+多基因遗传分析

Genetic analysis of stigma traits with genic male sterile line by mixture model of major gene plus polygene in rice(Oryza sativa L.)

柱头性状是影响水稻不育系异交繁殖和杂交水稻制种产量的重要性状。为创制长柱头、高外露率的水稻温敏核不育系提供遗传信息,调查了短柱头、低外露率的粳型光温敏核不育系7001S和长柱头、高外露率的温敏核不育系紫泰S及其杂交、自交获得的F_1、F_2群体(350个株系)和F_(2:3)群体(320个株系)的4个柱头性状,分析了4个性状之间的相关性,并运用主基因+多基因混合遗传模型,对2个世代4个性状进行了遗传分析。结果表明,4个柱头性状间均表现出极显著正相关,相关系数介于0.262和0.895之间。柱头长度、花柱长度、柱头和花柱总长度(以下简称柱花总长度)均表现出受2对主效基因和微效基因共同控制,除F_2群体中柱花总长度的2对主基因表现为等加性效应和等显性效应外,其余均表现为加性-显性-上位性效应,3个性状均表现出以主基因间的上位性效应为主;F_2群体柱头外露率受2对加性-显性-上位性主基因+多基因控制,而F_(2:3)群体则表现为受1对加性-显性主基因+多基因控制,以主基因间的加性效应为主。2个世代中的4个柱头性状均以主基因遗传为主。

Rice stigma traits are important traits that affects the yield of male sterile lines and hybrid rice seed production.To provide genetic information for the creation of thermo-sensitive genic male sterile lines with long stigmas and high exsertion rates in rice,we investigated the correlation among four stigma traits of 7001S(japonica photoperiod-thermo-sensitive genic male sterile line with short stigma length and low exsertion rate,P1),Zitai S(indica thermo-sensitive genic male sterile line with long stigma length and high exsertion rate,P2),and F1,F2(350 lines),and F2:3(320 lines)from the cross P1×P2.Coefficients of linear correlation in stigma traits were calculated,and genetic patterns were analyzed by mixed major-gene plus polygene inheritance models.The results showed that there were extremely significant linear positive correlations among four stigma traits.The correlation coefficients were between 0.262 and 0.895.Genetic analysis revealed that stigma length(STL),style length(SYL),the sum of stigma,and style length(TSSL)were controlled by two major genes plus polygenes.The two major genes expressed additive-dominant-epistatic effects,but they expressed equal additive effects and equal dominant effects of TSSL in F2 population.The epistatic effect was dominant in STL,SYL,and TSSL in F2 and F2:3.Percentage of exserted stigma(PES)was controlled by two major genes plus polygenes with additive-dominant-epistatic effect in F2.However,PES was controlled by one major gene with additive-dominant effect plus polygenes in F2:3.The additive effect was dominant of PES in F2 and F2:3.Four stigma traits were mainly governed by major genes.