小麦挑旗期和抽穗期的QTL分析

QTL Mapping of Flag Leaf Stage and Heading Date of Wheat

挑旗期和抽穗期是小麦重要的农艺性状,与小麦的开花期和成熟期密切相关。本研究利用小麦BS20/Fu3的DH群体的289个系,分别于2005-2006和2006-2007两个年度将该群体种植于北京和安徽阜阳,田间调查挑旗期和抽穗期,采用复合区间作图法,对挑旗期和抽穗期进行QTL分析。研究结果表明,挑旗期共有3个主效QTL,分别位于1BL、1DL和6BL,贡献率为3.34%￣14.31%;抽穗期共有4个主效QTL,分别位于1BL、1DL、4AL和6BL染色体上,贡献率为4.93%￣19.98%。挑旗期与抽穗期共同的QTL位于1BL、1DL和6BL,分别与cfa2129、cfd65和Xgwm58紧密连锁,与cfa2129的遗传距离为3.49￣13.39cM,与cfd65的遗传距离为0.05￣2.05cM,与Xgwm58的遗传距离为0.06cM。抽穗期位于4AL上的QTL,只在阜阳两年种植的材料中检测到,与最近标记Barc170的遗传距离为1.7￣6.1cM,可能由于不同生态环境诱导不同基因的表达。挑旗期和抽穗期的QTL基本一致,推测由于基因的多效性或控制不同性状的基因紧密连锁所致,同时从分子水平验证了两个性状的高度相关性。

Flag leaf stage and heading date are significant agronomic traits of wheat, which are relevant with flowering and mature stage. In this study, with 289 of doubled-haploid （DH） population derived from BS20×Fu3, the population was planted for two years in Beijing and Fuyang, Anhui province, and the field survey of flag leaf stage and heading date was conducted. The method of composite interval mapping （CIM） was used for QTL mapping of flag leaf stage and heading date. The result indicated that three major QTLs for flag leaf stage were located on chromosome 1BL, 1DL and 6BL, and their general contributions were 4.47%～14.31%, 6.27%～7.03% and 3.34%～5.03% respectively. For heading date, four major QTLs were located on chromosome 1BL, 1DL, 4AL and 6BL, and their general contributions were 10.72%～13.6%, 8.53%～19.98%, 6.97%～8.47% and 4.93%～7.38% respectively. The QTLs on 1BL, 1DL and 6BL had the same interval for flag leaf stage and heading date, and both were closely linked to cfa2129, cfd65 and Xgwm58, and the genetic distance were 3.49～13.39 cM, 0.05～2.05 cM and 0.06 cM, respectively. The QTL of heading date on 4AL was detected only in planting material of Fuyang of Anhui province, which genetic distance was 1.7～6.1 cM. A possible explanation for this is that different ecological environment induces varied heterogenic expression. The result show that QTLs of flag leaf stage and heading date were consistent may indicate that the gene pleiotropism or genes controlling different characters were closely linked, so the significant phenotypic correlations between flag leaf stage and heading date were verified on the molecular level.