枣疯病和酸枣丛枝病植原体16S rDNA和tuf基因的序列同源性分析

The Homology Analysis for Sequences of 16S rDNA and tuf Gene of Phytoplasma from Jujube Witches′ Broom and Wild Jujube Witches′ Broom

【目的】枣疯病是枣树上由植原体引起的一种毁灭性病害,遍布于中国华北、西北、华东、华南等25个省(市)的枣区,造成了巨大的经济损失。【方法】经PCR扩增,分别对中国陕西的彬县、阎良、武功、佳县、杨凌,河北沧州和山东德州7个枣区的枣疯病样品和杨凌4个酸枣丛枝病样品植原体16SrDNA基因保守序列和延伸因子tuf基因进行克隆和测序。【结果】获得枣疯病和酸枣丛枝病植原体的16SrDNA基因片段均为1239bp,tuf基因均为851bp。通过序列同源性比较,结果表明中国陕西、河北、山东的枣疯病的病原一致,归属于植原体16SrⅤ-B组。由于枣疯病和酸枣丛枝病的植原体16SrDNA有5个碱基的差异,tuf基因的同源性为99.6%,推测为同一个种的不同寄主生物学型。【结论】首次报道了中国枣疯病和酸枣丛枝病植原体16SrDNA和延伸因子tuf基因的序列,确定了枣疯病和酸枣丛枝病植原体的分类地位,为研究枣疯病植原体的致病分子机理、遗传本质提供理论依据。

[Objective] Jujube witches＇ broom （JWB）, a destructive disease caused by phytoplasma, happened in 25 provinces （cities） in China caused great economic loss. [Method] Jujube witches＇ broom and wild jujube witches＇ broom were investigated in Binxian, Yanliang, Wugong, Yangling, Jiaxian of Shaanxi, Cangzhou of Hebei, Dezhou of Shandong. The 16S rDNA and tuf gene were cloned by polymerase chain reaction from samples of JWB and wild jujube witches＇ broom. They were then sequenced. [Result] The 1 239 bp and 851 bp DNA fragement were amplified in DNA samples not only from infected jujube but also from infected wild jujube. It is found that 16S rDNA is 1 239 bp, tuf gene is 851 bp. The homology analysis for sequences of 16SrDNA and tuf gene shows that pathogens from Shaanxi, Hebei, Shandong are the same and belong to the 16SrV-B group. Because there are five different nucleotides in 16S rDNA between JWB and wild jujube witches＇ broom, and the homology rate of nucleotide sequences of tuf gene is 99.6%, we estimated that wild jujube witches＇ broom is infected by different strain of JWB pathogen. [ Conclusion] This article reported sequences of JWB and wild jujube witches＇ broom phytoplasmas differentiated and classified phytoplasma of JWB and wild jujube witches＇ broom. It provided theory for research of the molecular nosogenesis of JWB phytoplasma and genetic basis.