利用重组自交系进行陆地棉(GossypiumhirsutumL.)棉籽油分含量和蛋白质含量的QTL定位

Identification of QTL for Cottonseed Oil and Protein Content in Upland Cotton(Gossypium hirsutum L.) Based on a RIL Population

本研究利用以0—153为父本和SGK9708为母本构建的196个陆地棉重组自交系（F6：8）为材料对棉籽油分含量和蛋白质含量进行了遗传分析和QTL定位。通过四个环境下的群体材料的棉籽油分含量和蛋白质含量分析表明棉籽油分含量和蛋白质含量均为典型数量性状，其中棉籽油分含量存在超低亲本的超亲分离，而其蛋白质含量呈现超高亲本的超亲分离。相关性分析显示棉籽油分含量和蛋白质含量呈极显著负相关，同步提高两者在棉籽的的含量较为困难。基于包含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，应用WinQTLcart2．5软件对四个环境下的棉籽油分含量和蛋白质含量进行了QTL定位，共检测到8个油分含量QTLs，解释表型变异5．42％～13．15％，其中稳定的QTL1个。4个蛋白质含量QTLs，解释表型变异4．35％～14．93％。本研究结果可为进行陆地棉种子营养品质性状的分子遗传改良奠定基础。

In the study, the population of 196 recombinant inbred lines （F6：8） of upland cotton derived from the cross of 0-153 and SGK9708 was used to analyze heredity and identify quantitative trait loci （QTLs） for cottonseed oil and protein contents. The analysis of oil and protein in cottonseed in 4 environments indicates that oil and protein contents in cottonseed are typical quantitative traits, among which oil in cottonseed existed transgressive segregations lower than the low parent, while cottonseed protein content showed transgressive segregations higher than the high parent. The correlation analysis in the four environments displayed that oil content was negatively correlated with protein content in great significance, which indicates that it is difficult to improve the content of oil and protein in cottonseed simultaneously. Based on a genetic map of 186 SSR markers and a total genetic distance of 827.84 cM with an average interval of 4.45 cM between two markers and covering about 18.6% of cotton genome, 8 QTLs were detected for oil contents and contributed to the phenotypic variation （PV） by 5.42%-13.15%, in which 1 QTL was identified stably. 4 QTLs were detected for protein contents and contributed to the phenotypic variation （PV） by 4.35%-14.93%. The results lay the foundation for molecular genetic improvement of nutritional quality of upland cottonseed.