论文部分内容阅读
【目的】生物土壤结皮(Biological soil crusts,BSCs)对于遏制土壤荒漠化、恢复荒漠地区生态环境起着重要作用。BSCs形成和发展的关键角色是微生物。但关于BSCs中微生物组成的认识还不够全面和系统,特别是对其中的古菌鲜有研究报道。【方法】通过构建和分析古菌16S rRNA基因克隆文库,揭示浑善达克沙地BSCs中古菌多样性和系统发育类型组成,并比较它们夏季和冬季的变化。【结果】BSCs样品颜色为褐色,厚度较薄,所含氮和磷营养养分不高;8月份和11月份的BSCs古菌16S rRNA基因文库覆盖度均达95%以上,代表性强;两个文库共得到可用的142条古菌16S rRNA基因序列,以0.03为Cutoff值、这些序列分入10个OTUs中,两个季节的最优势种群相同;8月份和11月份的古菌均属于奇古菌门,但群落结构存在很大的不同,即各自所独有的种群分别有1个和4个;BSCs中古菌多样性均不高,但11月份的明显高于8月份的。【结论】温带沙地浅色型BSCs中古菌的主要为奇古菌、多样性低,其群落结构随季节变换而有较大变化。本研究为系统认识BSCs古菌的多样性及其生态作用提供了基础。
【Objective】 Biological soil crusts (BSCs) play an important role in curbing soil desertification and restoring the ecological environment in desert regions. The key role of BSCs in their formation and development is microbes. However, the understanding of microbial composition in BSCs is not yet comprehensive and systematic, especially for archaea rarely reported. 【Method】 The archaeal 16S rRNA gene cloning library was constructed and analyzed to reveal the diversity and phylogenetic composition of archaea in BSCs of Hunshandake sandy land and their changes in summer and winter were compared. 【Result】 The BSCs samples were brown in color and thin in thickness with low nutrient content of nitrogen and phosphorus. The coverage of 16S rRNA gene library of BSCs reached more than 95% in August and November, with strong representativeness. A total of 142 available sequences of archaeal 16S rRNA genes were obtained from the library. Cutoff values of 0.03 were used. These sequences were divided into 10 OTUs. The most dominant species in the two seasons were the same. The archaea in August and November all belonged to Oddok However, the community structure is quite different, that is, there are one and four populations respectively. The diversity of archaeal bacteria in BSCs is not high, but in November it is obviously higher than that in August. 【Conclusion】 The archaeal bacteria of light-colored BSCs in temperate sandy land are mainly Archaea, with low diversity and large changes in community structure with seasons. This study provided the basis for systematic understanding of the diversity of archaeal organisms and their ecological effects.