【摘要】 利用长江流域推广品种泗棉3号和优异纤维种质系7235为育种亲本,配置了系统育种和修饰回交聚合育种两套群体。基于来自7235的2个高强纤维主效QTL的分子标记,在上述育种群体中进行了分子标记辅助选择效率研究。高强纤维主效QTLfs1是利用(7235×TM1)F2分离群体,通过集团混合分离法检测到的,它可解释纤维强度表型变异的30%以上。高强纤维主效QTLfs2最初是利用(HS42710×TM1)F2分离群体检测到的,它可解释纤维强度表型变异的12.5%以上。进一步的研究表明,该QTL也位于7235优质系中,但与QTLfs1非等位。2套育种分离群体的2个高强纤维主效QTL的分子标记辅助选择效果表明:QTLfs1在不同环境条件下均稳定表达,它对不同遗传背景的育种群体均有显著的选择效果。尽管QTLfs2的选择效果低于QTLfs1,它在高世代育种群体中也表现较高的选择效率。利用分子标记辅助选择具有一定遗传距离的QTLfs1区间,其纤维强度的选择效率将大大增强。通过分子标记对位于不同连锁群上的2个QTL聚合选择,其中选单株的纤维强度显著提高。研究结果为利用分子标记辅助聚合优质QTL提供了成功实例。更多还原

【Abstract】 Based on two major QTLs that control high fiber strength which originated from an elite fiber germplasm line 7235 (Gossypium hiusutum L.),the efficiency of molecular marker-assisted selection (MAS) was investigated using two populations from pedigree selection and modified backcrossing pyramiding developed for the breeding purpose.Simian 3 (SM3),a widely planted variety in the Yangtze River Valley,and 7235 were used as parents to develop the two populations.In the two major QTLs for fiber strength from 7235,QTLfs-1 could explain more than 30% of the phenotypic variation (PV) in the (7235 ×TM-1) F2 population.QTLfs-2 was at first identified in another super quality fiber line HS427-10 from (HS427-10×TM-1) F2 population with 12.5% of PV explanation,which was further also identified in 7235 line but was non-allelic with QTLfs-1.The result of molecular marker-assisted selection for fiber strength showed that the genetic effect of the QTLfs-1 was stable under different environmental conditions,and its molecular marker-assisted selection showed significant selective efficiency among breeding populations with different genetic backgrounds.QTLfs-2 also showed high selective efficiency in advanced generation populations though its effect was a little lower than the former.When QTLfs-1 was selected simultaneously with 2 molecular markers with known genetic distance,the selection efficiency for the fiber strength was greatly increased.The pyramiding for two QTLs that control high fiber strength by MAS greatly improved the selection efficiency for cotton fiber strength.This report provides a successful example of MAS pyramiding for QTL for favorable traits in breeding programs.更多还原