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为研究我国重要经济树种喜树根际分泌物对根际微生物群落的影响,以及喜树在控制林业有害植物紫茎泽兰生物入侵的可行性,采用传统培养技术和分子生物学技术PCR-单链构象多态性(SSCP)、末端限制性片段长度多态性(tRFLP)和16S rDNA文库相结合对喜树(Ca)、紫茎泽兰(Ea)和二者混栽体系(CE)根际土壤中的真核微生物和真细菌微生物群落结构进行了比较.计数结果表明,喜树、二者混栽以及紫茎泽兰根际中的真细菌数量依次减少,而真核微生物数量依次增多.PCR-SSCP分析显示,紫茎泽兰根际土壤中真核微生物条带数量(多样性)远高于喜树和混栽根际,对部分条带克隆测序表明喜树根际中Meristolohmanniaspp.为主要优势种群;tRFLP对真细菌结构分析表明,3种根际中真细菌群落多样性丰富,但没有差别,对喜树根际真细菌16S rDNA文库测序比较分析,共包含了10个已分类的门,其中Proteobacteria门为优势菌群,占24.71%(其中δ-Proteobacteria占17.65%),Acidobacteria门占16.47%,Bacteroidetes门占10.59%.另外,色谱分析发现喜树和混栽根际土壤中分别含有较低浓度喜树碱和羟基喜树碱,而紫茎泽兰根际二者均检测不到.由此可见,紫茎泽兰的扩散和蔓延依赖于特有的真核微生物群落结构模式,并不改变真细菌群落的结构,喜树能够通过根系分泌物改变紫茎泽兰根际真核微生物群落结构模式,进而制约其外延.本研究为喜树在紫茎泽兰生物替代中提供了理论基础.
In order to study the effect of rhizosphere secretions on rhizosphere microbial communities in the important economic tree species of our country and the feasibility of controlling the biological invasion of the harmful plant Phoebe Eupatorium in the forestry industry by using the traditional culture technology and molecular biology technique PCR- (CaCP), Eupatorium adenophorum (Ea) and the root of the two mixed systems (CE) were determined by SSCP, tRFLP and 16S rDNA libraries. The comparison of eucaryotic microorganism and eubacterial community structure in the rhizospheric soil showed that the number of eubacteria in the rhizosphere of Camptotheca acuminatum, Eupatorium adenophorum and Eupatorium adenophorum decreased and the number of eukaryotic microbes increased .PCR-SSCP analysis showed that the number (diversity) of eukaryotic microorganisms in rhizosphere soil of Eupatorium adenophorum was much higher than that of Camptotheca acuminate and mixed rhizosphere. The cloning and sequencing of some of the bands showed that Meristolohmanniaspp was found in the rhizosphere of Camptotheca acuminata. As the main dominant species. The structural analysis of eubacteria by tRFLP showed that the eubacteria communities in the three kinds of rhizosphere were rich in diversity, but there was no difference. The sequence analysis of 16S rDNA of eucalyptus rhizosphere bacteria contained 10 classifieds The door, which Proteobacter ia was dominant, accounting for 24.71% (accounting for 17.65% of which were δ-Proteobacteria), Acidobacteria (16.47%) and Bacteroidetes (10.59%). In addition, chromatin analysis showed that Camptotheca acuminata and mixed rhizosphere soil had lower Concentration of camptothecin and hydroxycamptothecin, whereas neither Eupatorium adenophorum nor rhizosphere could detect it.It can be seen that the proliferation and spread of Eupatorium adenophorum depend on the unique eukaryotic microbial community structure pattern, which does not change The structure of eubacterial community, Camptotheca acuminata can change the eucalyptus adenophorum rhizosphere eucalyptus rhizosphere microbial community structure pattern by root exudates, and then restrict its extension.This study provided the theoretical basis for Camptotheca acuminata in biological substitution of Eupatorium adenophorum.