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作 者 ：杨娜;杨波

期 刊 ：植物科学学报 2011年 29卷 2期 页码：156-163

关键词：蕙兰；内生细菌；群落结构；核糖体DNA扩增片段限制性分析(ARDRA)；季节变化；

Keywords:Cymbidium faberi, Endophytic bacteria, Community structure, ARDRA, Seasonal fluctuation,

摘 要 ：为了研究蕙兰(Cymbidium faberi)根部内生细菌群落结构在不同季节里的变化,于不同季节从蕙兰根部分离出内生细菌207株,采用核糖体DNA扩增片段限制性分析(ARDRA)研究了蕙兰根部内生细菌群落组成的季节动态变化。将内生细菌纯培养物扩增近全长的16S rDNA,并用ARDRA对所分离的菌株进行分型,根据酶切图谱的差异,将其分成25个ARDRA型,并选取代表性菌株进行16S rDNA序列测定。结果表明,分离出来的内生细菌分为9个属,包括芽孢杆菌属(Bacillus)、伯克氏属(Burkholderia)、类芽孢杆菌属(Paenibacillus)、假单胞属(Pseudomonas)、微杆菌属(Microbacterium)、根瘤菌属(Rhizobium)、Lysinibacillus、Cohnella和短杆菌属(Brevibacterium),其中优势种群为Bacillus,次优势种群为Paenibacillus和Burkholderia。秋季分离出的内生细菌种类最多,夏季分离出的种类最少。在不同季节蕙兰内生细菌群落结构差异极显著(p<0.001),但在不同季节里蕙兰根部内生细菌优势种群没有差异。

Abstract:The paper investigated the seasonal variations in the community structure of endophytic bacteria in the root tissues of Cymbidium faberi Rolfe.A total of 207 bacterial isolates were obtained in different seasons.Based on the pattern of amplified ribosomal DNA restriction analysis(ARDRA) using restriction enzyme Alu I,the bacteria were grouped into 25 operational taxonomic units(OTUs).Phylogenetic analysis based on 16S rDNA gene homological data showed that all isolates affiliated to nine genera,consisting of Bacillus,Burkholderia,Paenibacillus,Pseudomonas,Microbacterium,Rhizobium,Lysinibacillus,Cohnella and Brevibacterium.Bacillus dominated among the bacterial isolates,followed by Paenibacillus and Burkholderia.Isolate diversity was lowest in summer and highest in September.The correlation between the community structure of endophytic bacteria and seasonal factors reached a highly significant level(p<0.001).However,the dominant species of the bacterial communities in Cymbidium faberi did not change significantly.

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