长白山亚高山苔原带土壤微生物研究

发布时间：2018-05-01 11:06

本文选题：苔原带 + 牛皮杜鹃　；参考：《吉林大学》2017年博士论文

【摘要】：本研究采用16S r RNA高通量测序(Illumina Mi Seq)技术、Real-time PCR和高效液相色谱法(HPLC)分别分析长白山亚高山苔原土壤微生物群落结构,碳氮循环功能基因相对丰度和真菌生物量。以长白山北坡苔原带牛皮杜鹃根际土壤作为主要研究对象,分析了不同海拔牛皮杜鹃根际土壤、同一海拔不同植物类型根际土壤以及不同植物群落牛皮杜鹃根际土壤微生物群落结构。结果表明:(1)不同海拔牛皮杜鹃(Rhododendron aureum Georgi)根际土壤理化性质差异显著,海拔2600m土壤总氮(TN)和总有机碳(TOC)含量显著低于其他海拔;海拔≥2300m根际土壤酸性磷酸酶活性显著高于低海拔(2300);不同海拔真菌生物量差异显著,但与海拔梯度没有显著相关性;不同海拔牛皮杜鹃根际土壤碳氮循环功能基因相对丰度具有显著性差异。聚类分析结果表明,高海拔(≥2400m)牛皮杜鹃根际土壤微生物群落结构组成相似。(2)相同海拔不同植被根际土壤理化性质、真菌生物量和碳氮循环功能基因相对丰度差异显著,其中在海拔2200m~2600m牛皮杜鹃根际土壤总有机碳含量显著高于同海拔其他植被处理。同时,对比其他植物,牛皮杜鹃根际土壤具有较高的养分循环功能微生物及真菌生物量。以上结果表明牛皮杜鹃对苔原带根际土壤具有一定改良作用。相关性分析结果表明除氨氧化古细菌外,土壤p H值与其他碳氮循环功能基因相对丰度显著相关;真菌生物量与土壤总有机碳、总氮、微生物量碳和蔗糖酶活性显著正相关。物种相对丰度分析和热图(Heatmap)结果表明,在高海拔2600m不同植物根际土壤微生物群落结构相似,而其他海拔不同植物根际土壤微生物群落组成差异较大。其中在海拔2300m~2500m牛皮杜鹃根际土壤微生物群落组成没有和同海拔其他两种植被处理聚在一起。通过测定牛皮杜鹃与不同植物物种混生根际土壤发现,牛皮杜鹃与草本植物混生(Da+H)其根际土壤总有机碳含量显著低于牛皮杜鹃独立群落(Da)和与木本混生植物群落(Da+S),其他土壤养分含量不同处理间差异不显著。牛皮杜鹃与其他植物混生,根际土壤真菌生物量、固氮和固碳功能基因相对丰度显著低于牛皮杜鹃独立群落(Da)根际土壤。OTU richness分析发现,牛皮杜鹃与草本植物混生,根际土壤微生物多样性显著低于其独立群落(Da)。NMDS结果表明,不同植物群落牛皮杜鹃根际土壤微生物群落结构组成差异不显著。这说明牛皮杜鹃具有自身特有的根际土壤微生物群落结构,受到植物群落变化影响较小。(3)利用结构方程模型(SEM)综合分析不同影响因素和土壤微生物之间的作用关系。结果表明,土壤有机碳(λ=0.51,P=0.002)和植物盖度(λ=0.504,P=0.004)是根际土壤真菌生物量的最直接控制因素;土壤p H是最主要的影响根际土壤微生物多样性(λ=-0.551,P=0.008)和群落组成(λ=0.850,P0.001)的直接作用因素;但从对根际土壤微生物总作用角度上看,海拔因素对根际土壤微生物群落结构总作用最强(λ=0.603),其主要通过影响土壤p H和TOC间接作用根际土壤微生物群落。以长白山西坡小叶章(Deyeuxia angustifolia)上侵为主要研究对象,分析了其上侵对苔原带土壤微生物的影响。结果表明,(1)小叶章上侵长白山西坡苔原带木本和草本植物群落,侵入地土壤理化性质变化显著,但是不同植物群落其变化幅度有所差异。小叶章上侵显著增加了木本植物群落侵入地根际土壤总有机碳和总氮含量,但草本植物群落侵入地其变化不显著。苔原带草本植物侵入地根际土壤有效养分增加幅度高于木本植物侵入地。物种差异分析和NMDS结果表明侵入地木本植物根际土壤微生物群落结构与小叶章侵入前差异显著,并且共有4个细菌门和18个菌属相对丰富度差异显著。而草本植物根际土壤微生物群落结构小叶章侵入前后差异不显著,没有发现相对丰富度有显著性差异的细菌门,共发现2个菌属丰富度差异显著。(2)功能微生物相对丰度差异分析发现,小叶章根际土壤固氮微生物功能基因相对丰度显著高于苔原带本土木本植物根际土壤,而在木本植物侵入地,根际土壤固氮微生物丰富度显著高于小叶章侵入前。苔原带本土植物与小叶章根际土壤微生物群落结构(多样性及群落组成)差异显著,而侵入地与小叶章根际土壤微生物多样性及群落结构没有显著性差异。以上说明小叶章侵入,能够有效改变根际土壤微生物群落,形成与自身生长相似的微生物环境。(3)植物群落调查结果表明,小叶章上侵显著降低了侵入地植物物种多样性和地上生物量。小叶章的侵入能够显著增加地上凋落物厚度,相关性分析也表明侵入地土壤总有机碳变化率与地上凋落物厚度变化率显著正相关。说明小叶章通过带来大量地上掉落物,促进了侵入地根际土壤养分的增加。
[Abstract]:In this study, 16S R RNA high throughput sequencing (Illumina Mi Seq) technology, Real-time PCR and high performance liquid chromatography (HPLC) were used to analyze the soil microbial community structure, the relative abundance of carbon and nitrogen cycle function and the biomass of fungi in Changbai Mountain subalpine tundra, and the main study was the soil of Rhododendron Rhizosphere in the tundra zone on the northern slope of Changbai Mountain. The microbial community structure of rhizosphere soil of Rhododendron rhizosphere at different altitudes, rhizosphere soil of different plant types at the same altitude and different plant communities of Rhododendron rhizosphere soil were analyzed at different altitudes. The results showed that: (1) there were significant differences in soil physical and chemical properties of rhizosphere soil of Rhododendron aureum Georgi at different altitudes, and the total nitrogen (TN) and total nitrogen (TN) at altitude of 2600m The content of total organic carbon (TOC) was significantly lower than that of other altitudes, and the activity of acid phosphatase in 2300m rhizosphere soil was significantly higher than that of low altitude (2300), and there was significant difference in the biomass of fungi at different altitudes, but there was no significant correlation with the elevation gradient; the relative abundance of carbon and nitrogen cycle function genes in the rhizosphere soil of Rhododendron at different altitudes was significantly different. The results of cluster analysis showed that the composition of microbial community structure in the rhizosphere soil of Rhododendron was similar at high altitude (> 2400m). (2) the relative abundance of fungi biomass and carbon nitrogen cycle function was significant in the soil physical and chemical properties at the same altitude, and the total organic carbon content in the rhizosphere soil of Rhododendron was significantly higher in 2200m ~2600m. Compared with other plants, the rhizosphere soil of Rhododendron had higher nutrient cycling function and fungi biomass compared with other plants. The results showed that Rhododendron had a certain improvement on the rhizosphere soil of tundra. The results of correlation analysis showed that the P H value of soil and other carbon in the soil with ammonia oxidation and oxidation of paleobacteria. The relative abundance of nitrogen cycle function genes was significantly correlated; fungal biomass was significantly correlated with soil total organic carbon, total nitrogen, microbial biomass carbon and invertase activity. Species relative abundance analysis and heat map (Heatmap) results showed that the microorganism community structure in rhizosphere soil of different plants at high altitude of 2600m was similar, and other plant rhizosphere soil at different altitudes. The microbial community composition of soil microbes was very different. The microbial community composition of the rhizosphere soil of Rhododendron rhizosphere at 2300m~2500m altitude was not combined with the other two plants at the same altitude. By measuring the rhizosphere soil of Rhododendron and different plant species, the total organic carbon of rhizosphere soil of Rhododendron and herbage was mixed (Da+H) in the rhizosphere soil of the Rhododendron. The content was significantly lower than the independent community of Rhododendron (Da) and the woody mixed plant community (Da+S), and there was no significant difference between the other soil nutrient contents. The relative abundance of the rhizosphere soil fungi and the relative abundance of nitrogen fixation and carbon fixation genes were significantly lower than the.OTU ric in the rhizosphere soil of the Rhododendron (Da). Hness analysis found that Rhododendron was mixed with herbaceous plants, and the microbial diversity in rhizosphere soil was significantly lower than that of its independent community (Da).NMDS. The results showed that the diversity of microbial community structure in the rhizosphere soil of Rhododendron was not significant. This indicated that the Rhododendron had its own unique microbial community structure in rhizosphere soil. The influence of plant community changes was small. (3) the structural equation model (SEM) was used to synthetically analyze the relationship between different influence factors and soil microorganism. The results showed that soil organic carbon (lambda =0.51, P=0.002) and plant coverage (lambda =0.504, P=0.004) were the most direct controlling factors of fungi biomass in rhizosphere soil; soil P H was the most important influence root. The direct action factors of soil microbial diversity (lambda =-0.551, P=0.008) and community composition (lambda =0.850, P0.001), but from the point of view of the total microbial interaction in rhizosphere soil, the total effect of altitude on the microbial community structure of rhizosphere soil was the strongest ([lambda =0.603) ", and its main purpose was to indirectly influence the soil microorganism group by influencing soil P H and TOC. The influence of invading on the soil microorganism in the tundra zone was analyzed with the main research object of Deyeuxia angustifolia in the western slope of Changbai Mountain. The results showed that (1) the invasion of the soil physical and chemical properties of the intrusive soil was significant, but the variation range of the different plant communities was significant. The invasion of herbaceous plant communities intruded the total organic carbon and total nitrogen in the rhizosphere soil of the woody plant community, but the changes in the invasive sites of herbaceous plants were not significant. The increase of effective nutrients in the rhizosphere soil of the tundra with herbaceous plants was higher than that of the invasive sites of woody plants. Species difference analysis and NMDS results showed invasive sites. The microbial community structure in the rhizosphere soil of woody plants was significantly different from that before the intruding of the leaflets, and there were a total of 4 bacterial gates and 18 bacteria phases, but the difference was not significant before and after the invasion of the rhizosphere soil microbes, and there was no significant difference in the relative abundance of bacteria, and 2 of the bacteria found a total of 2. The difference of the abundance of the genus was significant. (2) the analysis of the relative abundance difference of functional microorganisms found that the relative abundance of nitrogen fixing microbial functional genes in the rhizosphere soil was significantly higher than that of the native woody plant rhizosphere soil of the tundra, but the abundance of nitrogen fixing microorganism in the rhizosphere soil was significantly higher than that before the invasion of the lobule. There are significant differences in microbial community structure (diversity and community composition) in soil plants and lobular rhizosphere soil, but there is no significant difference in microbial diversity and community structure between the intruder and the rhizosphere soil. The above indicates that the intruding of the leaflet can effectively change the microbiological community of the rhizosphere soil and form the microorganism similar to its own growth. (3) the results of plant community survey showed that the invasion of the leaflets significantly reduced the species diversity and aboveground biomass of the invasive plants. The invasion of the leaflets could significantly increase the thickness of the litter, and the correlation analysis also showed that the change rate of total organic carbon in the intrusive soil was positively correlated with the variation rate of the aboveground litter thickness. By increasing the number of fallen soil, the nutrient content of the rhizosphere soil was increased.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：Q948.113

【相似文献】