应用16SrDNA克隆文库解析苏铁珊瑚状根内生放线菌种群多样性

Application of 16S rDNA clone library analysis for Cycas spp. coralloid roots endophytic actinomycetes population diversity

苏铁为古老孑遗植物，被誉为“植物界的大熊猫”和“活化石”。为了研究苏铁珊瑚状根内生放线菌的多样性，通过16SrDNA克隆文库开展了珊瑚状根内生放线菌种群多样性研究，从16SrDNA克隆文库中随机挑选了164个克隆子进行序列测定，对测序结果进行了Blast对比，结果表明，苏铁珊瑚状根中放线菌多样性十分丰富，存在5个目7个科10个属，主要类群为短小杆菌属Curtobacterium、利夫森氏菌属Leifsonia、考克氏菌Kocuria、鸟氨酸微菌属Ornithinimicrobium、微球菌属Micrococcus、丙酸杆菌属Propionibacterium、链霉菌属Streptomyces、拟诺卡氏菌属Nocardiopsis、芽球菌属Blastococcus；克隆得到的内生放线菌优势菌为短小杆菌属Curtobacterium，其次为拟诺卡氏菌属Nocardiopsis和链霉菌属Streptomyces。其中68株内生放线菌是能分离培养的，经16SrDNA片段测序分析，结果表明这些内生放线菌分别与GenBank中已知属相似性达97％-100％；其余的序列相似性低于97％，表明苏铁珊瑚状根中可能存在着放线菌新种。

Cycas ancient relict plant, known as the ＂plant Panda＂ and ＂living fossil＂ . In order to have diversity of actinomycetes of Cycas coral root, the actinomycetes diversity in Cycas coral root of was studied by 16S rDNA cloning and sequencing method. 164 clones were randomly selected, and their 16S rDNA genes were sequenced and blasted. The results showed that the Cycas coral mycorrhiza exist actinomycete resource rich. Distributed in 5 orders and 7 families, 10 genera. These 10 genera were Curtobacterium, Leifsonia, Chryseoglobus, Kocuria, Ornithinimicrobium, Micrococcus, Propionibacterium, Streptomyces, Nocardiopsis, Blastococcus. The advantage of actinomycetes actinomycetes as Curtobacterium students within the cloned （Curtobacterium）, followed by quasi Nocardia and Streptomyces （Nocardiopsis） （Streptomyces）. Similarity is less than 97%, the partial sequence in clone libraries showed that, there may be Actinomyces species in the coralloid root.