野生二粒小麦抗条锈病基因YrH52的RGA分子标记

Resistance Gene Analog Markers Linked to the Stripe Rust Resistance Gene YrH52 Derived from Wild Emmer Wheat,Triticum dicoccoides

为开发与野生二粒小麦抗条锈病基因Yr H52紧密连锁的分子标记,并为该基因的克隆及应用奠定基础,运用RGA(Resistance gene analog)分子标记法,以Yr H52定位作图F2群体形成的F4抗性和感病基因池(Gene pool)及其亲本(抗病材料H52与感病材料Ldn)进行多态性筛选分析,共获得17个RGA分子标记。使用已有的遗传图并进行MultiPoint分析,构建了由与抗性(H)和感病(L)两个亲本对应的显性位点组成的两个遗传图,即H遗传图和L遗传图。在H图中,Yr H52与10个RGA标记,即X_uhw3,X_uhw17,X_uhw18,X_uhw23,X_uhw36,X_uhw38,X_uhw46,X_uhw59,X_uhw62和X_uhw73紧密连锁,其中X_uhw23标记为共显性分子标记,连锁距离为1.0 c M。在L图中,发现X_uhw57,X_uhw68,X_uhw189,X_uhw192及其X_uhw23与Yr H52相聚成簇(Cluster)。本研究结果说明RGA分子标记结合集群分离分析法(Bulked segregant analysis,BSA)是一种快速开发与小麦抗病基因紧密连锁标记的有效方法,对小麦抗条锈病分子育种和抗病基因的克隆具有促进作用。

The wheat stripe rust resistance gene YrH52,derived from wild emmer wheat,Triticum dicoccoides,was previously mapped on chromosome 1BS.The aim of the present study was to develop resistance gene analog（RGA） markers linked to YrH52 for future marker-assisted selection in wheat and cloning of the resistance gene YrH52.The bulked segregate analysis（BSA） was used to screen DNA pools of resistant vs.susceptible progenies,and 17 RGA markers linked to YrH52 were obtained.Two versions of genetic maps were constructed with skeleton and added markers by MultiPoint based on the previous linkage map of T.dicoccoides,respectively.As added markers in the H version map,the YrH52 and 10 RGA markers（X_uhw3,X_uhw17,X_uhw18,X_uhw23,X_uhw36,X_uhw38,X_uhw46,X_uhw59,X_uhw62 and X_uhw73） were linked tightly together within genetic distance of 1.0 cM.In the L version map,four RGA markers,X_uhw57,X_uhw68,X_uhw189,X_uhw192 and also X_uhw23 were clustered with YrH52.These results demonstrate the RGA sequences combination with BSA,was a useful method for rapidly generating markers tightly linked to resistance loci in wheat.The RGA approach will greatly benefit the marker-assisted selection in wheat and cloning of the resistance gene YrH52.