不同盐碱程度盐碱土壤微生物多样性研究

发布时间：2018-03-13 01:03

本文选题：河套灌区　切入点：盐碱土壤　出处：《内蒙古师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：本研究选择内蒙古巴彦淖尔市河套灌区的盐土、强度盐化土和轻度盐化土三种不同盐碱程度的土壤作为研究对象,以磷脂脂肪酸(phospholipid fatty acid,PLFA)、变形梯度凝胶电泳(Denaturing gradient gel electrophoresis,DGGE)和实时荧光定量(Real-time fluorescent quantitative,PCR)等技术为切入点,以盐碱土壤微生物群落结构为主线,探讨了不同盐碱程度土壤的环境特点,及盐碱程度对土壤微生物群落结构、多样性和细菌种类、生态功能的影响等。研究结果如下:(1)通过磷脂脂肪酸(PLFA)法定量分析,表明不同盐碱程度盐碱土壤微生物PLFA总量、表征细菌和真菌的PLFA含量以及多样性指数从大到小依次为轻度盐化土、强度盐化土、盐土。土壤中磷脂脂肪酸标记物与土壤全磷、土壤全氮和土壤有机质之间具有极强的相关性。(2)变性梯度凝胶电泳(DGGE)结果显示,盐土、强度盐化土和轻度盐化土不论在0~20 cm层还是20~30 cm层,土壤细菌群落多样性和丰富度从大到小依次为轻度盐化土、强度盐化土、盐土;0~20 cm层与20-30 cm层的土壤细菌群落之间存在显著性差异,随着土层的加深,土壤细菌群落多样性和丰富度减小。不同盐碱程度盐碱土壤中细菌群落的Shannon-Wiener指数与土壤电导率w(EC)(r=-0.542,P0.05)、pH(r=-0.526,P0.05)和土壤容重(r=-0.523,P0.05)呈显著负相关,与土壤有机碳w(SOC)(r=0.700,P0.01)和w(TP)(r=0.805,P0.01)呈极显著正相关。在一定范围土壤pH、w(EC)和容重越低,土壤w(SOC)、土壤全氮w(TN)和全磷w(TP)越高,土壤细菌群落的多样性和丰富度也越高。w(EC)和pH对盐碱土壤细菌群落结构的影响力最大。变形菌(α-变形菌纲、β-变形菌纲、γ-变形菌纲和δ-变形菌纲)是盐碱土壤的主要类群。DGGE测定盐碱土壤中的菌株主要属于耐盐碱的细菌菌株,并且都是耐硫酸盐细菌。(3)实时荧光定量(PCR)技术结果显示,随着土壤盐碱程度的升高,细菌数量从大到小的顺序依次为轻度盐化土、强度盐化土和盐土。盐碱土壤中细菌的数量与电导率(r=-0.904,P0.01)和p H(r=-0.804,P0.01)呈极显著负相关,细菌的数量与TP(r=0.772,P0.05)和SOC(r=0.732,P0.05)显著相关,细菌的数量与水分(r=-0.786,P0.05)呈显著负相关,与土壤全氮的关系不显著(r=0.481,P0.05)。(4)PLFA和PCR-DGGE结合阐明不同盐碱程度土壤的微生物多样性,是一种有效和互补的途径。PLFA技术并不能在种的水平上说明土壤微生物群落结构发生的变化。而PCR-DGGE法可以揭示具体微生物种群的变化,证实不同盐碱土壤优势细菌类群不同,以变形菌纲为主,主要属于耐盐碱细菌菌株。DGGE多样性指数适合用来讨论盐碱土壤的微生物多样性。土壤w(EC)、pH、土壤容重、w(SOC)、w(TN)和w(TP)是盐碱土壤的主要环境因子,并且盐度和碱度是影响不同盐碱程度盐碱土壤中微生物群落结构显著影响因素。
[Abstract]:In this study, three kinds of saline soil, strong saline soil and mild salinized soil, were selected as the research objects in Hetao Irrigation area of Bayan Nur City, Inner Mongolia. Based on the techniques of phospholipid fatty acidine, denaturing gradient gel electrophoresisn (DGGE) and real-time fluorescence quantitative fluorescent (real-time fluorescent), the environmental characteristics of soils with different salinity and alkali-alkali degree were discussed. The effects of salinity on soil microbial community structure, diversity, bacterial species and ecological function. The results are as follows: (1) quantitative analysis of microbial PLFA in saline-alkali soil with different salinity was made by means of phospholipid fatty acid (PLFA) method. The PLFA content and diversity index of bacteria and fungi were in the order of light salinized soil, strong saline soil, salt soil, phospholipid fatty acid marker and total phosphorus in soil. There was a strong correlation between soil total nitrogen and soil organic matter. (2) denaturing gradient gel electrophoresis (DGGE). The results showed that saline soil, intensively salinized soil and mild salinized soil were in the layer of 20 cm or 20 ~ 30 cm, respectively. The diversity and richness of soil bacterial community were in the order of light salinized soil, intensity salinized soil, soil bacterial community of 20 cm layer and 20-30 cm layer of salt soil, and the soil bacterial community was significantly different with the deepening of soil layer. The diversity and richness of soil bacterial communities decreased. The Shannon-Wiener index of bacterial communities in saline-alkali soils with different salinity levels was negatively correlated with soil electrical conductivity (WEC) -0.542 (P 0.05) and soil bulk density (r ~ + -0.523 ~ (+) P _ (0.05)). There was a significant positive correlation with soil organic carbon (WSC) 0.700 (P0.01) and WTP-0.805 (P0.01). The lower the soil pH value, the lower the bulk density, the higher the soil WSOC, soil total nitrogen and phosphorus (WTPN), and the higher the soil total phosphorus (WTP), the higher the soil total nitrogen (WN) and total phosphorus (WTP). The higher the diversity and richness of soil bacterial community is, the greater the influence of pH and pH on the bacterial community structure in saline-alkali soil. Proteus (伪 -Proteus, 尾 -Proteus, 纬 -Proteus and 未 -Proteus) are the main components of saline-alkali soil. In order to determine the strains in saline-alkali soil by DGGE, they mainly belong to saline-alkali tolerant bacteria. The results of real-time fluorescence quantitative analysis (PCR) showed that with the increase of soil salinization degree, the order of bacteria number from large to small was light salinized soil. The number of bacteria in the saline soil was negatively correlated with the conductivities (P 0.01) and P 0.01 (P 0.01), and the number of bacteria was significantly correlated with TPRN 0.772P 0.05 (P 0.05), and the number of bacteria was negatively correlated with the water content (ru -0.786P 0.05), and the number of bacteria was negatively correlated with the water content (P 0.05), and the number of bacteria was negatively correlated with the concentrations of TPRN 0.772P 0.05 (P 0.05), and the number of bacteria was negatively correlated with the water content (P 0.05), and the amount of bacteria was negatively correlated with the water content (P 0.05). The relationship between soil total nitrogen and soil total nitrogen was not significant. The microbial diversity of soils with different saline-alkali levels was elucidated by the combination of PLFA and PCR-DGGE. PLFA is an effective and complementary approach. PLFA can not explain the change of soil microbial community structure at the species level, but PCR-DGGE method can reveal the change of specific microbial population, and prove that the dominant bacteria groups in different saline-alkali soil are different. The microbial diversity index of saline-alkali tolerant bacteria strain. DGGE is suitable to discuss the microbial diversity of saline-alkali soil. The pH of soil WECN, soil bulk density (WSCC) and WTP-are the main environmental factors of saline-alkali soil, and the main environmental factors of saline-alkali soil are DGGE diversity index (DGGE diversity index). Moreover, salinity and alkalinity were significant influencing factors of microbial community structure in saline-alkali soils with different salinity and alkalinity.
【学位授予单位】：内蒙古师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S156.4;S154.3

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