用根据核苷酸结合位点 (nucleotidebindingsite ,NBS)和丝氨酸 /苏氨酸蛋白质激酶域设计的 2对简并性引物 ,以小麦_簇毛麦 6VS/ 6AL易位系的cDNA为模板进行PCR扩增。扩增产物克隆到pGEM_T载体中 ,经测序 ,共获得具有NBS结构域特征的片段克隆 9个和具有丝氨酸 /苏氨酸蛋白质激酶域特征的片段的克隆 1个。将克隆之间核苷酸序列同源性高于 90 %的克隆归为一类 ,把 9个NBS片段分为 6类。这 6类抗病基因类似序列 (resistancegeneanalogs ,RGA)均具有阅读框 ,并与已克隆的小麦抗条锈病基因Yr10、大麦抗白粉病基因Mla1和Mla6、拟南芥的抗病基因RPS2以及其他一些抗病基因在NBS保守区内具有高度的同源性。用小麦中国春缺体_四体初步将它们分别定位于小麦第一、第二和第五部分同源群上。进一步用 5′_RACE技术获得RGAN5的 5′_端 ,发现其编码产物的N端还具有 6个亮氨酸拉链 (leucinezipper,LZ) ,与RPS2的N_端有较高同源性。 Two pairs of degenerate primers designed based on nucleotide binding sites (NBS) and serine / threonine protein kinase domains were used for PCR amplification using the cDNA of wheat-cluster wool 6VS / 6AL translocation line as a template increase. The amplified product was cloned into pGEM_T vector and sequenced to obtain 9 clones with NBS domain signature and 1 clone with the serine / threonine protein kinase domain. Clones with more than 90% nucleotide sequence homology between clones were grouped into one class and nine NBS fragments were grouped into six classes. These six resistance geneanalogs (RGA) all have the reading frame and are closely related to the cloned wheat stripe rust resistance gene Yr10, barley powdery mildew resistance genes Mla1 and Mla6, Arabidopsis thaliana resistance gene RPS2 and others Resistance genes have a high degree of homology in the conserved region of NBS. They were all located in the first, second and fifth homologous groups of wheat with the initial stage of the Chinese spring mesityrbody-wheat. The 5’-end of RGAN5 was further obtained by 5’_RACE technique. The N-terminus of RGAN5 was also found to have six leucine zippers (LZ), which had high homology with the N-terminus of RPS2.