title: [Nucleotide polymorphism and molecular evolution of the LRR region in potato late blight resistance gene Rpi-blb2].
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 populations. 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.
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China. ylp19860805@163.com
authors.forename: Lu-Peng
authors.initials: LP
authors.lastname: You
authors.forename: Jing
authors.initials: J
authors.lastname: Miao
authors.forename: Ai-Lan
authors.initials: AL
authors.lastname: Zou
authors.forename: Jin-Liang
authors.initials: JL
authors.lastname: Qi
authors.forename: Yong-Hua
authors.initials: YH
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D060467:Disease Resistance / Q000235:genetics*; D019143:Evolution, Molecular; D017343:Genes, Plant; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics*; D011110:Polymorphism, Genetic; D011198:Solanum tuberosum / Q000235:genetics*