多环境下陆地棉(Gossypium hirsutum L.)重组自交系铃重与衣分性状的QTL分析

Identification of QTL for Boll Weight and Lint Percentage of Upland Cotton (Gossypium hirsutum L.) RIL Population in Multiple Environments

本研究利用以SGK9708为母本,0-153为父本构建的196个陆地棉重组自交系(F6:8)构建了包含186个标记,总长827.84cM,标记间平均距离4.45cM,覆盖棉花基因组18.6%的遗传连锁图谱,并对7个环境下的铃重和衣分性状进行QTL定位和上位性互作分析。利用两种分析软件(WinQTLcart2.5和QTLNetwork2.0)共同定位了多个环境下稳定表达的5个主效QTLs(qBW-1-1,qBW-1-2,qLP-2-1,qLP-2-2和qLP-4-2)。利用QTLNetwork2.0分别检测到4对铃重上位性互作QTLs和7对衣分上位性互作QTLs,以背景位点间的互作和加性效应位点与背景位点间的互作为主。除主效QTL外,上位性效应也是陆地棉铃重和衣分性状的重要遗传基础。本研究定位的5个主效QTLs为选择高铃重、高衣分品种的棉花分子标记辅助育种提供了重要依据。

In this study, a population of 196 recombinant inbred lines （F6：8） of upland cotton derived from the cross of 0-153 and SGK9708 was used to develop a genetic linkage map including 186 SSR markers. The map spanned 827.84 cM with an average interval of 4.45 cM between two markers and covered about 18.6% of cotton genome. Meanwhile, QTL mapping and interaction analysis of epistasis for boll weight and lint percentage in 7 environments were also conducted. 5 major QTLs （qBW-1-1, qBW-1-2, qLP-2-1, qLP-2-2 and qLP-4-2） expre- ssing stably in multi-environments were both detected by two software （WinQTLcart2.5 and QTLNetwork2.0）. Four epistatic QTLs for boll weight and 7 epistatic QTLs for lint percentage were detected separately by QTLNetwork2.0; most of the interaction types were between background loci and additive effect×background locus interaction. Except for major effects of QTLs, epistasis effects played an important role in the genetic basis for boll weight and lint percentage of upland cotton. 5 major QTLs detected in our study would provide an important reference for marker-assisted breeding with big boll weight and high lint percentage.