稻田土壤固碳功能微生物群落结构和数量特征

发布时间：2018-03-29 14:11

本文选题：稻田土壤　切入点：自养固碳微生物　出处：《环境科学》2017年02期

【摘要】：研究不同类型稻田土壤自养微生物数量和多样性差异及其影响因子,对全面认识稻田生态系统的固碳潜力及其机制具有重要意义.鉴于此,本文选取4种典型稻田土壤,通过室内培养实验对具备卡尔文循环途径碳同化微生物进行了研究.利用荧光定量PCR(qPCR)、克隆文库以及末端限制性长度多态性分析(T-RFLP)技术,研究了卡尔文循环关键酶(1,5二磷酸核酮糖羧化酶/加氧酶Rubis CO)的2种编码基因(cbbL和cbbM)的丰度和多样性.结果表明,与培养前相比,培养45 d后碳同化自养微生物数量有所增加,cbbL基因丰度比cbbM基因高3个数量级.不同稻田土壤中碳同化功能微生物优势种群存在差异,且这些微生物大多不能归类到已知的细菌类群中,部分可归类的与变形菌和放线菌有较高相似度.RDA分析结果显示土壤有机碳(SOC)、阳离子交换量(CEC)、pH、黏粒、粉粒和砂粒含量对碳同化功能微生物群落结构有显著影响.本文的研究结果对于理解微生物在碳循环过程中的作用具有一定的科学意义,也可以为稻田土壤肥力科学化管理和构建低碳农业提供科学依据.
[Abstract]:It is important to study the number and diversity of autotrophic microorganisms in different types of paddy soils and their influencing factors, which is of great significance to fully understand the carbon sequestration potential and its mechanism of paddy ecosystem. In view of this, four typical paddy soils are selected in this paper. The carbon assimilation microbes with Calvin cycle pathway were studied in laboratory culture. The fluorescent quantitative PCR qPCRN, clone library and terminal restriction length polymorphism (TRFLP) technique were used. The abundance and diversity of two coding genes of the key enzymes of Calvin cycle, ribonucleose diphosphate carboxylase / oxygenase Rubis CO), were studied. The results showed that, compared with those before culture, the two coding genes, cbbbL and cbbM, were more abundant and diverse than those before culture. After 45 days of culture, the number of carbon assimilation autotrophic microbes increased by 3 orders of magnitude higher than that of cbbM gene. There were differences in dominant microbial populations of carbon assimilation function in different paddy soils. And most of these microbes can not be classified into known bacterial groups. Some of them have high similarity with Proteus and actinomycetes. RDA analysis results show that soil organic carbon (SOC), cationic exchange capacity (CEC) pH, clay, etc. The content of silt and sand has a significant effect on the structure of microbial community with carbon assimilation function. The results of this paper are of scientific significance in understanding the role of microorganisms in the process of carbon cycling. It can also provide scientific basis for scientific management of soil fertility and construction of low carbon agriculture.
【作者单位】：中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室;中国科学院大学;中南林业科技大学生命科学与技术学院;中国科学院亚热带农业生态研究所公共技术服务中心;
【基金】：国家自然科学基金项目(41522107,41301275)
【分类号】：S154.3

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