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为准确分析定殖在根际和非根际土壤的细菌类群组成,采用454高通量测序技术,对杨树人工林根际和非根际细菌群落进行对比分析.本次测序共获得原始序列70 081条,过滤后序列总数为44 009条.物种注释结果显示,根际土壤包含145个细菌属,非根际土壤包含141个细菌属.根际和非根际相对丰度>4%的属有8个,它们是Acidobacterium GP1、Acidobacterium GP3、Acidobacterium GP6、Gemmatimonas、Bradyrhizobium、Burkholderia、Streptomyces和Acidobacterium GP4,同一属的细菌类群在根际和非根际土壤中相对丰度存在显著差异(P<0.05).α多样性分析表明,根际土壤细菌群落多样性高于非根际土壤,但差异未达到显著水平.细菌群落排序结果较好地反映了土壤细菌群落从根际到非根际的变化和不同取样点的空间差异,根际效应对细菌群落差异的贡献率占21.2%.β多样性分析表明,杨树人工林根际和非根际土壤样品间细菌群落组成具有较大差异,根际和非根际土壤中各含有一些特有属(根际15个,非根际11个),此外还发现丰度发生显著变化的23个属,主要以纤维素降解菌和固氮菌属为主.本研究表明,根系对根际微生物的选择是导致根际微生物群落组成和结构发生显著差异的重要机制,这将对根土界面碳氮循环产生显著影响.
In order to accurately analyze the bacterial colonies colonized in rhizosphere soil and non-rhizosphere soil, the rhizosphere and non-rhizosphere bacterial communities of poplar plantations were compared using 454 high-throughput sequencing technology.This sequencing obtained a total of original sequence 70 081 and the total number of filtered sequences was 44 009. Species annotation results showed that rhizosphere soil contained 145 bacterial genera and non-rhizosphere soil contained 141 bacterial genera.The relative abundance of rhizosphere and non-rhizosphere> 4% There are 8 genera in this study, which are Acidobacterium GP1, Acidobacterium GP3, Acidobacterium GP6, Gemmatimonas, Bradyrhizobium, Burkholderia, Streptomyces and Acidobacterium GP4. The relative abundance of bacteria in the same genera in rhizosphere and non-rhizosphere soil is significant difference (P < 0.05) .α diversity analysis showed that the diversity of bacterial community in rhizosphere soil was higher than that in non-rhizosphere soil, but the difference did not reach significant level.The sequencing of bacterial community better reflected the change of soil bacterial community from rhizosphere to non-rhizosphere Changes and sampling points of different spatial differences, rhizospheric effects on bacterial community differences accounted for 21.2% of the contribution.β diversity analysis showed that poplar plantations rhizosphere and non-rhizosphere soil bacteria There are some differences in the composition of the community, rhizosphere and non-rhizosphere soil contains some endemic genera (15 rhizosphere, 11 non-rhizosphere), in addition to found significant changes in abundance of 23 genera, mainly in cellulose Degrading bacteria and azotobacter.The results showed that root system selection of rhizosphere microorganisms is an important mechanism leading to significant differences in composition and structure of rhizosphere microbial communities, which will have a significant impact on the carbon and nitrogen cycle of root-soil interface.