利用水稻F_2群体对其抽穗期和株高的QTL定位

利用遗传作图群体对水稻抽穗期和株高进行QTL定位,以明确控制性状的基因,揭示性状的遗传机制。将粳型品种月之光与籼型品种明恢63杂交(月之光×明恢63),获得一个含189个家系的F2遗传作图群体;利用该群体建立含127个SSR标记的遗传连锁图谱,图谱覆盖12条染色体,连锁群总长度2 123cM,标记间平均距离16.7cM。F2群体抽穗期和株高均表现为连续的数量变异,呈正态分布,且出现明显的双向超亲分离,抽穗期和株高之间呈现极显著的正相关。以QTL作图软件Cartgrapher 2.5对F2群体抽穗期和株高性状进行了QTL定位分析,共定位到4个与抽穗期相关的QTLs,分别分布于第1、6、8、12号染色体上,第8号染色体上的qHD8 LOD值为10.70,贡献率达48.0%,是主效基因,与已克隆的DTH8在相近位置,可能是DTH8。定位到4个与株高相关的QTLs,分别位于第1、3、8、12号染色体上,表型贡献率为6.3%～21.1%,第1号染色体上检测到的qPH1能解析21.1%的表型变异,是主效基因,位于矮秆基因sd1附近,可能是sd1。定位到的这些QTLs是进行分子标记辅助选择改良相应性状的候选基因位点。

QTL Mapping for Heading Date and Plant Height of Rice Using F2 Population from Yuezhiguang× Minghui 63

QTL mapping was conducted to study the genes controlling heading date and plant height of rice and their genetic mechanism.Using a F2 population of 189 individuals derived from the cross Yuezhiguang(Japonica) × Minghui 63(Indica),the genetic linkage map including 127 SSR markers was generated by software Cartgrapher 2.5,covering 12 chromosomes with a total length of 2 123 cM and an average interval size of 16.7 cM.Four QTLs for heading date were detected,located on chromosome 1,6,8 and 12,respectively,among which the qHD8,with a LOD score of 10.70 and located on chromosome 8,could account for 48.0% of the total phenotypic va-riation(being a major gene),and might be the DTH8,a gene associated with the heading date of rice.Meanwhile,four QTLs related to plant height were detected on chromosome 1,3,8 and 12,explaining 6.3%-21.1% of the total phenotypic variation,respectively,among which the qPH1 on chromosome 1 could account for 21.1% of the total phenotypic variation,should be a major gene,and might be sd1 gene because it was in the vicinity of dwarf gene sd1.All the QTL information was useful for molecular breeding to improve the traits of heading date and plant height.