利用永久F_2群体在不同光周期环境下定位玉米株高QTL

Detection of Quantitative Trait Loci for Plant Height in Different Photoperiod Environments Using an Immortalized F_2 Population in Maize

为了研究热带玉米株高的遗传机制,利用温热组合黄早四×CML288衍生的重组自交系群体构建了一个包含278个组合的永久F2群体,分别在海南三亚、河南郑州和洛阳、北京昌平和顺义5个地点3种光周期环境中进行株高鉴定。利用复合区间作图法在3种光周期环境下共定位到12个不同的玉米株高QTL。位于第1染色体上的qPH1-2和位于第4染色体上的QTL qPH4在3个环境中同时被检测到,表明这2个QTL在不同日照环境下均能稳定表达。位于第3染色体上的qPH3在短日照环境下能解释株高遗传变异的32.13%,而在2个长日照环境下并未被检测到,表明此QTL是短日照环境下特异表达的主效QTL。第10染色体上QTLqPH10-1分别解释2个长日照环境中株高遗传变异的25.39%和39.58%,是长日照环境下特异表达的主效株高QTL。

For studying the genetic basis of plant height in maize,an immortalized F2 population of 278 F1 crosses was constructed by intercrossing recombinant inbred lines derived from a cross between temperate and tropical inbred lines（Huangzaosi × CML288）.The ＂immortalized F2＂ was evaluated for plant height in five locations with three photoperiod environments,i.e.a short day environment of Sanya in Hainan Province,long-day environments of Zhengzhou and Luoyang in Henan Province,and long-day environments of Shunyi and Changping in Beijing.Twelve QTLs for plant height were detected in different photoperiod environments using composite interval mapping.QTLs qPH1-2 and qPH4 associated with plant height were detected in all the three photoperiod environments,showing that these two QTLs might control plant height steadily in different environments.QTL qPH3 was detected for plant height and explained 32.13% of the phenotypic variation in short day environment while could not be detected in long day environment,which indicated that the QTL qPH3 might control plant height only in short day environment.QTL qPH10-1 in the bin 10.04 region of chromosome 10 associated with plant height was detected in long day environments of Henan and Beijing and explained 25.39% and 39.58% of the phenotypic variation,respectively.This result indicated that the QTL qPH10-1 might be a major QTL for plant height in long day environment.