遗传 ›› 2012, Vol. 34 ›› Issue (4): 485-494.doi: 10.3724/SP.J.1005.2012.00485

• 研究报告 • 上一篇    下一篇

马铃薯抗晚疫病基因Rpi-blb2的LRR区域多态性及分子进化分析

游录鹏, 苗婧, 邹爱兰, 戚金亮, 杨永华   

  1. 南京大学生命科学学院, 医药生物技术国家重点实验室, 南京 210093
  • 收稿日期:2011-07-03 修回日期:2012-01-08 出版日期:2012-04-20 发布日期:2012-04-25
  • 通讯作者: 杨永华 E-mail:YangYH@nju.edu.cn
  • 基金资助:

    教育部“创新团队”项目(编号:IRT1020) 资助

Nucleotide polymorphism and molecular evolution of the LRR region in potato late blight resistance gene Rpi-blb2

YOU Lu-Peng, MIAO Jing, ZOU Ai-Lan, QI Jin-Liang, YANG Yong-Hua   

  1. State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China
  • Received:2011-07-03 Revised:2012-01-08 Online:2012-04-20 Published:2012-04-25

摘要: 马铃薯抗晚疫病基因Rpi-blb2是来源于马铃薯野生种Solanum bulbocastanum中的一个具有广谱抗性的NBS-LRR类抗病基因。文章用PCR的方法从20个高抗晚疫病的马铃薯栽培种和20个高感晚疫病的马铃薯栽培种以及7个马铃薯野生种中克隆了Rpi-blb2基因的 LRR区段。采用生物信息学方法对这些序列的相似性、多态性位点、核酸多样性指数等参数进行了分析, 发现Rpi-blb2 的LRR区域在核酸水平上变异程度很高, 而且存在多处热点突变位点; 通过对该区域的Ka/Ks值进行估算, 发现Rpi-blb2 的LRR区域总体上受到纯化选择, 功能保守, 但是LRR区域的不同部位所受到的选择压力却不尽相同。同时, 从核酸水平来看, Rpi-blb2 基因的LRR区域在马铃薯栽培种和马铃薯野生种之间没有发现明显的分化。

关键词: 马铃薯晚疫病, Rpi-blb2, LRR区域, 多态性

Abstract: Rpi-blb2, which is originally derived from Solanum bulbocastanum, is a broad-spectrum potato late blight resistance gene and belongs to the NBS-LRR family. Here, the LRR homologues of Rpi-blb2 were cloned with PCR method from 40 potato cultivars (including 20 resistant potato cultivars and 20 susceptible ones) and 7 wild potato popula-tions. Then, the similarities of the sequences, polymorphic (segregating) sites, and nucleotide diversities were estimated by bioinformatic methods. The results showed that high nucleotide polymorphism and some hot-spot mutations existed in the LRR region of Rpi-blb2. The test of Ka/Ks ratio showed that the function of LRR was conserved because of the purifying selection, although different positions of the Rpi-blb2 LRR region were under different selection pressures. Moreover, the LRR region of Rpi-blb2 had no clear differentiation between the cultivated and wild potatoes.

Key words: potato late blight, Rpi-blb2, LRR region, polymorphism

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