基于多个相关群体的玉米雄穗相关性状QTL分析

QTL Analysis of Tassel-Related Traits in Maize(Zea mays L.) Using Multiple Connected Populations

为了解析玉米雄穗相关性状的遗传机制,利用以黄早四为共同亲本组配的11个重组自交系群体,对玉米雄穗一级分枝数、雄穗主轴长和雄穗干重3个性状进行QTL分析。经过对11个群体及亲本2年3点的田间鉴定,单环境和联合环境下的玉米雄穗相关性状QTL定位,及基因型与环境互作和上位性互作分析,检测到15个在多环境下(5个环境以上)稳定表达的"环境钝感"主效QTL,其中,在染色体bin3.04区域,齐319群体和旅28群体中都定位到1个主效雄穗一级分枝数相关QTL,其平均贡献率分别为17.4%和14.4%,并且2个群体的QTL标记区间高度重叠,在IBM2008 Neighbors图谱上的重叠区间为226.0～230.1。对比不同群体结果发现,在2个群体以上都能检测到的一致性区间21个,其中在第2、第3、第6、第8染色体上的5个一致性区间在3个群体中可稳定表达。这些多环境和多个遗传背景下稳定表达的位点可作为玉米雄穗性状分子标记辅助选择、精细定位及基因克隆的候选位点。

Maize tassel-related traits are of importance to maize production.QTLs for three tassel-related traits were mapped in 11 RIL populations with the common parent ＂Huangzaosi＂ under a single environment and across environments to understand genetic basis of maize tassels.Meanwhile,epistasis among QTLs and QTL by environment interactions（QEI） was analyzed.Totally 15 major constitutive QTLs were detected in at least five environments.Particularly,two constitutive QTLs were detected in bin 3.04 in the Qi 319 and Lü 28 populations,which had an overlapping interval of 226.0-230.1 on the IBM 2008 Neighbors map,with a quite high phenotypic variance explained,and the mean R2 of 17.4% and 14.4%,respectively.A total of 21 common QTLs were detected in more than two populations,of which five on chromosome 2,3,6 and 8 were found in three populations.The QTLs stably expressed under different environments or genetic backgrounds may play an important role in controlling maize tassel-related traits,and can be used as the candidates for fine mapping and positional cloning.