小麦抗叶锈病基因Lr9的分子标记及其检测

Genetic Improvement and Marker Assisted Selection of Wheat with Leaf Rust Resistance Gene Lr9

1B·1R易位系、高分子量麦谷蛋白亚基(HMW-GS)、多酚氧化酶(Polyphenol oxidase,PPO)活性、黄色素含量等因素都对小麦加工品质有重要影响,慢锈基因Lr34既抗叶锈,又抗条锈、白粉和秆锈病。为了明确这些基因在黑龙江小麦品种中的分布,并为优质抗病小麦分子标记辅助育种提供材料和方法,本研究利用高分子量谷蛋白亚基Dx5、By8、1B·1R易位系、PPO、PSY基因和Lr34位点的特异性分子标记对黑龙江省不同地区的169份小麦品种进行鉴定。结果表明,Dx5亚基的频率为43.2%,By8亚基的频率为30.8%,1B·1R易位系的频率为4.7%,Ppo-A1b的频率为33.1%,Psy-A1b的频率为33.7%,含Lr34位点的频率为24.9%;不含1B·1R易位系、同时又具有Dx5和By8、Ppo-A1b、Psy-A1b及Lr34位点的品种只有2份,占1.2%。

Leaf rust of wheat,caused by Puccinia triticina,is the most common rust disease worldwide.Wheat leaf rust resistance gene Lr9,derived from wheat-Aegilops umbellulata chromosome translocation of T6BS·6BL-6U#1L,was highly resistant to prevailing P.triticina isolates THT and PHT in China.An American common wheat variety Arthur 71 was used as donor of Lr9 to make cross with a highly susceptible common wheat line Xuezao for genetic and bulked segregated analyses using F2 population and F2：3 families.Six SSR markers,Xwmc179,Xbarc146,Xbarc198,Xcfa2110,Xbarc24,and Xbarc178,one EST-STS marker BE443156,and one EST-SSR marker XMAG799,were found to be linked to Lr9.Xwmc179,Xbarc146,BE443156 and XMAG799 were dominant markers,while Xbarc198,Xcfa2110,Xbarc24 and Xbarc178 were co-dominant markers.Lr9 was co-segregated with EST-STS marker BE443156,was in 3.4 cM distal to Xbarc178 and assigned to the distal bin of chromosome 6BL.STS marker J13/1＋2 and SCAR marker SCS5550 were proved to be co-segregated with Lr9 and could be used as powerful tool in marker assisted selection of Lr9.The SSR markers identified in this study could be used as markers for background selection.By applying a ＂rolling cycle accelerated backcrossing＂ approach,we developed a series of leaf rust resistance lines containing Lr9 with improved agronomic traits.