大豆幼苗根系性状的QTL分析

QTL Analysis of Root Traits of Soybean at Seedling Stage

为研究大豆幼苗期根系性状的遗传规律,以中豆29和中豆32构建的RIL群体为材料,在V2期测定水培幼苗根系性状(主根长、侧根数、根重、根体积和根冠比等)及相关性状(株重、茎叶重和下胚轴重等),以方差分析方法估算遗传参数,并采用复合区间作图法对大豆幼苗期根系等性状进行QTL定位。结果表明,在8个染色体上检测到20个根系及相关性状QTL,其中9个主效QTL位于第11和第14染色体,表型贡献率在10.5%～26.1%之间。在第11和第14染色体上,部分根系性状QTL与地上部性状QTL处于同一位置,其QTL的共位性与形态性状表型相关分析结果一致,反映了根系性状与地上部性状存在一定的关联。

Root system plays important roles in plant growth and development,including uptaking water and nutrient,resisting biotic and abiotic stresses,and finally influencing yield and quality.A number of QTLs for shoot traits have been detected using different populations in soybean [Glycine max（L.） Merr.],but rarely for root trait.The aim of the present study was to identify QTLs for some root traits at seedling stage in soybean.A total of 165 recombinant inbred lines（RILs） derived from the cross between Zhongdou 29 and Zhongdou 32 were used.Soybean seedlings were hydroponically cultured,root traits including main root length,number of lateral roots,root weight,root volume,and aerial part traits such as plant weight,shoot weight per plant,and ratio of root weight to shoot weight were measured at the stage of V2（first trifoliolate leaf fully expanded）.By composite interval mapping（CIM） method,twenty QTLs for roots and aerial part traits were mapped on eight chromosomes,including nine major-effect QTLs on chromosome 11 and 14 with 10.5-26.1% of the phenotypic variation.On chromosome 11 and 14,some QTLs for root traits and aerial part traits were clustered,which was consistent with the correlation analysis of phenotypic traits,indicating that the root traits are associated with the shoot traits.