桂西北不同植被恢复阶段土壤氨氧化细菌遗传多样性研究  

GENETIC DIVERSITIES OF SOIL AMMONIA-OXIDIZING BACTERIA AT VARIOUS VEGETATION RESTORATION STAGES IN SOUTHWEST GUANGXI,CHINA

作　　者：梁月明[1,2,3] 苏以荣[1,3] 张伟[1,3] 陈香碧[1,3] 刘淑娟[1,2,3] 黎蕾[1,2,3] 冯书珍[1,2,3] 何寻阳[1,3] 

机构地区：[1]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,长沙410125 [2]中国科学院大学,北京100049 [3]中国科学院环江喀斯特农业生态试验站,广西环江547100

出　　处：《土壤学报》2013年第2期364-371,共8页Acta Pedologica Sinica

基　　金：中国科学院知识创新重要方向项目(KSCX2-YW-JC403);中国科学院战略性先导科技专项(XDA05070403);国家科技支撑计划项目(2012BAD05B03-03);中国科学院西部之光(2009-2011)项目联合资助

摘　　要：以桂西北喀斯特不同植被恢复阶段(草丛、灌木林、次生林、原生林)生态系统为研究对象,运用分子生物学技术分析了土壤氨氧化细菌amoA功能基因多样性,探讨了其与脲酶活性和土壤理化性质的关系。结果显示,随着植被的恢复,土壤氨氧化细菌多样性指数与均匀度指数呈增大趋势(灌木林例外),且土壤中氨氧化细菌群落结构发生了改变:主要表现在因Nitrosospira 3簇种群对铵态氮浓度敏感度差异导致其在3a、3b簇中分布不一致;相关分析表明:土壤脲酶活性与铵态氮浓度呈正相关关系,土壤脲酶可能通过影响铵态氮浓度改变氨氧化细菌多样性,但植被恢复后期土壤铵态氮浓度减少并未降低土壤氨氧化细菌多样性。LIBSHUFF和RDA分析揭示,植被类型和土壤脲酶活性及pH与氨氧化细菌群落结构紧密相关,说明植被和土壤氮素有效性以及pH可能是决定土壤氨氧化细菌多样性的主要因子,为深入理解喀斯特地区土壤氮素循环提供了一定的科学依据。Soil samples were collected from soils under different vegetations, i.e. T （tussock） , S （shrub） , SF （secondary forest） and PF （primary forest）, representing different vegetation restoration stages in the Karst region in Southwest Guangxi, China, for analysis of genetic diversity of ammonia-oxidizing bacteria （AOB） and their relationships with urease activity and physico-chemical properties of the soil. Results show that with the advancement in vegetation res- toration, genetic diversity and Shannon and Evenness indices of AOB in the soil increased except for under tussock, and moreover, AOB community structure altered, with changes embodied in inconsistent distribution of Nitrosospira clusters 3a and 3b populations as a result of variation of the sensitivity of Nitrosospira cluster 3 population to ammonium concentration. Correlation analysis reveals that soil urease activity in the soil was positively related to ammonium content. Hence, soil urease may alter AOB diversity by affecting ammonium content. However, at the late stage of vegetation restoration, the lower ammonium content did not lead to any reduction in AOB diversity. LIBSHUFF and RDA analysis exposed that AOB community structure was closely related to vegetation type, soil urease activity and soil pH, indicating that vegetation, soil N availability and pH may possibly be the main factors affecting soil AOB diversity. These findings may serve as certain scientific basis for further understanding of soil N cycling in Karst region.

关 键 词：氨氧化细菌 喀斯特 脲酶活性 氮素 植被恢复 

分 类 号：S154.3[农业科学—土壤学] Q938.1[农业科学—农业基础科学]