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利用PYGV、R2A、NB和Czapek 4种培养基,研究了不同海拔下黑河上游祁连山区土壤细菌群落结构的变化规律.结果表明:可培养细菌数量为4.6×106～37.0×106 CFU·g-1,随海拔升高明显减少;基于16SrRNA基因序列分析共发现了7个门、19个属、26种细菌,其中Agreia pratensis,Mucilaginibacter ximonensis,嗜冷冷杆菌(Cryobacterium psychrophilum)和氧化节杆菌(Arthrobacteroxydans)四种细菌是优势种;嗜冷冷杆菌的相对丰度在高海拔地区明显增加,Agreia pratensis的相对丰度随海拔升高而降低;细菌的多样性随海拔升高呈现出先升高后降低的趋势.冗余分析(RDA)显示,可培养细菌数量与海拔呈显著负相关,细菌的多样性与植被指数和土壤理化性质均存在明显的相关关系,说明可培养细菌数量主要受海拔的影响,而植被和土壤理化性质是影响细菌群落多样性的主要因素.
The change of bacterial community structure in the Qilian mountainous area at different altitudes was studied by using PYGV, R2A, NB and Czapek culture media. The results showed that the number of culturable bacteria was 4.6 × 106 ~ 37.0 × 106 CFU · g-1 , With the altitude increased significantly reduced; based on 16SrRNA gene sequence analysis found a total of seven doors, 19 genera and 26 kinds of bacteria, of which Agreia pratensis, Mucilaginibacter ximonensis, cold chain bacteria (Cryobacterium psychrophilum) and Arthrobacter oxydans Four kinds of bacteria were the dominant species. The relative abundance of C. psychrophilis increased significantly at high altitude. The relative abundance of Agreia pratensis decreased with altitude. The diversity of bacteria increased firstly and then decreased with the altitude increasing Trend.RDA analysis showed that there was a significant negative correlation between the number of culturable bacteria and the altitude, and there was a significant correlation between bacterial diversity and vegetation index and soil physicochemical properties, which indicated that the number of culturable bacteria was mainly affected by altitude, Vegetation and soil physical and chemical properties are the main factors affecting the diversity of bacterial communities.