Guo Wang-Zhen, Zhang Tian-Zhen, Ding Ye-Zhang, Zhu Yi-Chao, Shen Xin-Lian, Zhu Xie-Fei
National Key Laboratory of Crop Genetics and Germplasm Enhancement, Cotton Research Institute, Nanjing Agricultural University, Nanjing 210095, China.
Yi Chuan Xue Bao. 2005 Dec;32(12):1275-85.
Based on two major QTLs that control high fiber strength which originated from an elite fiber germ-plasm 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 x TM-1) F2 population. QTLfs-2 was at first identified in another super quality fiber line HS427-10 from (HS427-10 x 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.
基于两个控制高纤维强度的主效QTL，它们源自一个优良纤维种质系7235（陆地棉），利用为育种目的而构建的系谱选择和改良回交聚合的两个群体，对分子标记辅助选择（MAS）的效率进行了研究。长江流域广泛种植的品种泗棉3号（SM3）和7235被用作亲本构建这两个群体。在来自7235的两个纤维强度主效QTL中，QTLfs - 1能解释（7235×TM - 1）F2群体中超过30%的表型变异（PV）。QTLfs - 2最初在另一个优质纤维品系HS427 - 10的（HS427 - 10×TM - 1）F2群体中被鉴定出来，能解释12.5%的PV，随后在7235品系中也被鉴定出来，但与QTLfs - 1非等位。纤维强度分子标记辅助选择的结果表明，QTLfs - 1的遗传效应在不同环境条件下稳定，其分子标记辅助选择在不同遗传背景的育种群体中显示出显著的选择效率。QTLfs - 2在高世代群体中也显示出较高的选择效率，尽管其效应略低于前者。当同时选择QTLfs - 1和两个已知遗传距离的分子标记时，纤维强度的选择效率大大提高。通过MAS对两个控制高纤维强度的QTL进行聚合，极大地提高了棉花纤维强度的选择效率。本报告为育种计划中有利性状QTL的MAS聚合提供了一个成功范例。
