新疆醉马草内生菌群落结构

摘要

[目的]揭示醉马草不同组织内生细菌和内生真菌种群组成和分布.[方法]采用液氮研磨法分别提取醉马草种子、叶、茎、根组织总DNA,采用通用引物扩增内生细菌16S rDNA和真菌ITS,通过限制性内切酶HhaⅠ和Rsa Ⅰ对16S rDNA PCR产物酶切,HhaeⅢ和Hinf Ⅰ对真菌rDNA ITS PCR产物酶切得到不同的TRFs片段.TRFs经T-RFLP分析程序结合基因文库比对后,分析醉马草不同组织中内生细菌和内生真菌的群落组成及内生菌群落相似性.[结果]研究表明醉马草根部内生细菌多样性最高,而种子内生真菌多样性最为丰富.醉马草各组织内生细菌优势菌属均为Bacillus(29％以上),种子、叶、茎、根内生真菌优势菌属分别为Mycosphaerella( 6.5％),Teratosphaeria (4.5％),Fragum( 1.1％),Sebacina( 11.3％).聚类分析表明茎和叶内生细菌群落结构相似,种子和其他组织内生细菌群落结构相似性较远,而茎和种子内生真菌群落结构相似,叶和其他组织内生真菌群落结构相似性较远.醉马草内生菌多样性丰富且存在尚未认识的新类群.%[Objective ] The aim of this study was to investigate the composition and distribution variation of endophytic bacteria and fungi in Achnatherum inebrians. [Methods] The DNA of seed, leaf, stem and root was extracted with liquid nitrogen grinding method. Then, 16S rDNA and Internally Transcribed Spacer ( ITS) sequence were digested with restriction enzymes Hha I , Rsa I and Hhae Ⅲ , Hinf I to obtain terminal restriction fragments. The terminal restriction fragments were matched to bacterial and fungal genera by the T-RFLP Analysis Program, and the community component and similarity of endophyte in Achnatherum inebrians were analyzed. [ Results] The diversity of endophytic bacteria and fungi was the most abundant in root and seed of Achnatherum inebrians. All the predominant bacterial population was Bacillus ( above 29% ) in different organs of Achnatherum inebrians. The predominant fungal population was Mycosphaerella (6. 5% ) , Teratosphaeria (4. 5% ) , Fragum (1. 1% ) , Sebacina (11. 3% ) in seed, leaf, stem and root, respectively. The structure of the bacterial communities in the stem and leaf were similar, whereas the structure of the bacterial communities in the seed and other tissue were different. The structure of the fungi communities in the stem and seed were similar, whereas the structure of the fungi communities in the leaf and other tissue were different. [ Conclusion ] There was abundant endophytic microbial diversity in Achnatherum inebrians.