青藏高原不同类型草地生态系统下土壤可培养细菌数量及多样性分布特征研究  

Features of Soil Cultivable Microorganism Quantity and Diversity Distribution under Different Alpine Grassland Ecosystems in Qinghai-Tibet Plateau

作　　者：陈伟[1] 张威[2] 李师翁[1] 王鹭[3] 贠汉柏[2] 伍修锟[2] 胡平[1] 杨轩[1] 冯虎元[3] 刘光琇[2] 

机构地区：[1]兰州交通大学化学与生物工程学院,甘肃兰州730070 [2]中国科学院寒区旱区环境与工程研究所沙漠与沙漠化重点实验室,甘肃兰州730000 [3]兰州大学生命科学学院,甘肃兰州730000

出　　处：《冰川冻土》2011年第6期1419-1426,共8页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金创新群体项目(40821001);国家自然科学基金项目(30800154;31170465;31100365;40971034);中国博士后科学基金项目(20080430794);甘肃省科技计划(1011FKCA114;1010RJZA009)资助

摘　　要：以青藏高原北麓河不同类型草地生态系统下土壤为研究对象,研究了可培养细菌数量和多样性的季节性变化.结果显示研究区域可培养细菌数量为0.4×107～4.6×107 CFU.g-1,不同类型草地生态系统下可培养细菌具有明显的季节差异:高寒沼泽草甸和高寒沙化草原生态系统下土壤细菌在5月生物量最高,而高寒草甸生态系统下在7月有最高的生物量;可培养细菌分属于α-变形菌(α-Pro-teobacteria),β-变形菌(β-Proteobacteria),γ-变形菌(γ-Proteobacteria),放线菌门(Actinobacteria),厚壁菌门(Firmicutes)5个类群,其中放线菌门为优势类群.不同类型草地生态系统有不同的细菌多样性特征,表明这种细菌多样性变化与相邻区域的差异性符合物种-区域关系,说明随着高山草原的退化,青藏高原各高山草地生态系统间已产生较大的环境异质性,而这种异质性进一步影响到了物种的多样性.结果为利用微生物综合评价高山草地的生态环境,并合理利用微生物资源改良青藏高原高山草原提供了数据基础及特有的微生物资源.Three representative alpine grassland ecosystems in the Qinghai-Tibet Plateau were selected to investigate the seasonal dynamics of their soil cultivable microorganisms.The results show that the amount of soil microorganism ranges from 0.4×107 CFU·g-1 to 4.6×107 CFU·g-1 and differs significantly with season.The amount of soil microorganism is the most in May in alpine sandy grassland and alpine cold swamp grassland,while is more in July in alpine-cold meadow.Based on the 16S rDNA gene sequence and phylogenetic tree,the cultivable bacteria in present study belong to 21 genera and fall into five phylogenetic groups： α-Proteobacteria,β-Proteobacteria,γ-Proteobacteria,Actinobacteria and Firmicutes,among which Actinobacteria is the predominant one.Further analysis shows that the bacteria are characterized by a taxa-area relationship.This relationship is governed primarily by environmental heterogeneity rather than geographic distance or plant composition.All these results present basic data for rationally using microbial resources and improving the Tibetan Plateau alpine grasslands.

关 键 词：青藏高原 高山草地生态系统 可培养细菌 系统发育树 

分 类 号：Q937[生物学—微生物学]