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以腾格里沙漠东南缘沙漠化土壤为研究对象,研究了不同沙漠化修复程度土壤结皮及结皮下微生物分布特征及多样性。结果表明:研究区域可培养细菌数量随沙漠化生态修复进程呈升高趋势,随采样深度呈下降趋势。数量以节杆菌属和芽孢杆菌属为主,其含量随沙漠化修复程度分别呈降低与升高趋势。修复过程中可培养土壤微生物数量与土壤碳、氮含量呈极显著正相关关系,与pH值呈极显著负相关关系,说明微生物数量与沙漠化土壤改良程度密切相关。通过16S rDNA基因测序及构建系统发育树,研究区域可培养细菌归类为18个属,分属于6个系统发育组:高G+C革兰氏阳性类群、低G+C革兰氏阳性类群、α-变形菌、β-变形菌、γ-变形菌和CFB类群,序列比对显示菌株功能多样。
Taking the desertified soil in the southeast edge of Tengger Desert as the research object, the characteristics and diversity of microorganisms in soil crusts and crusts under different degrees of desertification restoration were studied. The results showed that the number of culturable bacteria in the study area increased with the process of ecological restoration of desertification, and decreased with the sampling depth. The quantity was mainly Arthrobacter and Bacillus, and its contents decreased and increased with the degree of desertification. There was a significant positive correlation between soil microbial quantity and soil carbon and nitrogen content in the process of restoration, which showed a significant negative correlation with pH value, indicating that the number of microbes is closely related to the degree of desertification improvement. By 16S rDNA gene sequencing and phylogenetic tree construction, the study area can be divided into 18 genera of bacteria, belonging to 6 phylogenetic groups: high G + C Gram-positive group, low G + C Gram-positive group , Α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria and CFB groups. Sequence alignment showed that the strains were diverse in function.