Primary analysis of QTG contribution to heterosis in upland cotton  

作　　者：ZHANG XianLiang LIU Fang WANG Wei LI ShaoHui WANG ChunYing ZHANG XiangDi WANG YuHong WANG KunBo 

机构地区：[1]Cotton Research Institute, Chinese Academy of Agricultural Sciences, Key Laboratory of Cotton Genetic Improvement, Ministry of Agriculture of People's Republic of China, Anyang 455000, China [2]Kaifeng Research Academy of Agriculture and Forestry, Key Laboratory of Agriculture Biological Breeding, Kaifeng 475141, China [3]Yanhai District Agricultural Research Institute of Jiangsu Province, Yancheng 224002, China

出　　处：《Chinese Science Bulletin》2010年第26期2956-2965,共10页

基　　金：supported by the National High-Tech Research Program of China (2009AA-101104);National Natural Science Foundation of China (30170501)

摘　　要：In this paper, we analyzed the contribution of pure DNA factors to heterosis using quantitative trait genes (QTG) in two randomly selected strains from a recombinant inbred line of Gossypium hirsutum. According to a set of QTL mapping results, combined with analysis of DNA recombinant fragment sources in the two strains and QTL association analysis with their field traits, we hypothesize a view of "dominance + overdominance + epistasis". That is, additive and additive epistasis may be the genetic basis of heterosis, and dominance, overdominance and epistasis may be the modes of heterosis action. Based on the heterosis results of this study, we also suggest a molecular mechanism for heterosis, and explain, in detail, with two randomly selected strains as examples. The male and female parent-derived additive epistatic QTLs of upper half mean length in LG01 and LG03 produced a trait variance of 2.99-3.52 compared with the female parent-derived loci. The trait of bolls per plant was controlled by two pairs of additive epistatic QTLs in LG02 and LG07, which were derived from both female and male parents. The QTLs were reciprocally interacted and produced a trait variance of 0.86. An initial concept of "super-hybrid cotton" was raised according to the nature of additive effect, that is genetic stability.In this paper, we analyzed the contribution of pure DNA factors to heterosis using quantitative trait genes （QTG） in two randomly selected strains from a recombinant inbred line of Gossypium hirsutum. According to a set of QTL mapping results, combined with analysis of DNA recombinant fragment sources in the two strains and QTL association analysis with their field traits, we hypothesize a view of ＂dominance ＋ overdominance ＋ epistasis＂. That is, additive and additive epistasis may be the genetic basis of heterosis, and dominance, overdominance and epistasis may be the modes of heterosis action. Based on the heterosis results of this study, we also suggest a molecular mechanism for heterosis, and explain, in detail, with two randomly selected strains as ex- amples. The male and female parent-derived additive epistatic QTLs of upper half mean length in LG01 and LG03 produced a trait variance of 2.99-3.52 compared with the female parent-derived loci. The trait of boils per plant was controlled by two pairs of additive epistatic QTLs in LG02 and LG07, which were derived from both female and male parents. The QTLs were reciprocally interacted and produced a trait variance of 0.86. An initial concept of ＂super-hybrid cotton＂ was raised according to the nature of additive effect, that is genetic stability.

关 键 词：杂种优势利用 陆地棉 QTL定位 数量性状基因 重组自交系 显性上位 遗传基础 随机选择 

分 类 号：S512.1[农业科学—作物学] S562