水稻上部节间长度等数量性状基因的定位及其遗传效应分析

对水稻籼粳杂交（窄叶青８号×京系１７）Ｆ＿１的花药进行离体培养，建立一个含１３３个ＤＨ系的作图群体，通过构建分子连锁图谱，对水稻上部节间长度、株高和抽穗期的ＱＴＬ进行区间作图，定位了影响上部节间长度的１２个ＱＴＬ、株高的４个ＱＴＬ和抽穗期的１个ＱＴＬ。对这些ＱＴＬ的遗传效应分析的结果表明，控制抽穗期的１个ＱＴＬ即Ｈｄ８ａ为主效基因，其余的１６个ＱＴＬ为微效基因。控制上部节间长度单个的ＱＴＬ对表型的贡献率介于８－１８％，其加性效应可使所控制的节间长度增加大约１．６－３．６ｃｍ。值得注意的是，一些控制相关性状的、作用方向相同的ＱＴＬ定位于同一染色体的相同或邻近区段上。这一结果揭示了这些性状相关的遗传基础，在水稻育种中运用这些ＱＴＬ将有助于对株高进行精细的遗传调控。

Identification of QTLs for Lengthes of the Top Internodes and Other Traits in Rice and Analysis of their Genetic Effects

Zhaiyeqing 8 of indica and Jingxi 17 of Japonica are both semidwarf rice varieties that differ significantly in heading date, plant height and lengthes of the top three internodes. One hundred and thirty-three doubled haploid lines were produced by anther culture from the cross between Zhaiyeqing 8 and Jingxi 17, and were used to construct an RFLP map with 137 markers. Interval mapping identified 4 quantitative trait loci (QTL) for plant height and 12 QTLs for the length of top internodes. In addition,a major gene of heading date was also detected. The QTLs for the length of top internodes were identified as minor genes which individually explained 8-18% of the total phenotypic variation. Their individul genetic effects might increase the length of top internodes by 1.6-3.6cm. Some QTLs for plant height and the length of top internodes were mapped on the same or nearly linked regoins of the same chromosome. This result not only may partly explain the genetic basis of phenotypic correlation of these traits, but also will facilitate the marker-assisted selection for plant height in rice improvement programs.