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研究黄河三角洲光板地和4种盐生植被(翅碱蓬、獐茅、白茅和罗布麻)下土壤细菌群落组成,揭示其与盐生植被演替的关系。利用细菌16S r DNA基因文库方法,构建系统发育树,在5个文库中各挑选180个阳性克隆子进行序列测定,并对数据进行统计分析。从光板地、翅碱蓬、獐茅、白茅和罗布麻5个文库中分别得到121、132、150、159、155条有效序列。重盐土壤(翅碱蓬土壤、獐茅土壤)细菌有着最高的Shannon指数和最低的Simpson优势度指数。土壤中检测到变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、酸杆菌门(Acidobacteria)等,共8门。其中变形菌门在5种土样中相对丰度为21.06%,拟杆菌门为11.16%,其他细菌相对丰度皆未超过10%。5种覆被类型下土壤细菌在种群组成上差异明显,但均匀度与丰富度差异较小,变形菌为所研究5种土壤中的优势菌群。当盐生植被处于相同演替阶段时,土壤细菌群落结构具有更大相似性;在不同演替阶段时,土壤细菌群落结构差别较大。
The composition of soil bacteria community in the plateau of the Yellow River Delta and four halophytes (Suaeda stenoptera, Pomacea, Imperata cylindrica and Apocynum venetum L.) was studied to reveal its relationship with the succession of halophyte vegetation. The phylogenetic tree was constructed by bacterial 16S r DNA gene library, and 180 positive clones were selected from 5 libraries for sequence analysis and the data were statistically analyzed. 121,132,150,159,155 validated sequences were obtained from 5 libraries of light plate, Suaeda stenoptera, Pomacea, Plum and Apocynum. The bacteria in the heavy salt soil (Suaeda scripus soil, solanum terrestris soil) had the highest Shannon’s index and the lowest Simpson’s dominance index. A total of 8 Proteobacteria, Bacteroidetes, Acidobacteria were detected in soils. Among them, the relative abundance of Proteobacteria was 21.06% in 5 kinds of soil samples and 11.16% in Bacteroidetes. The relative abundance of other bacteria did not exceed 10%. The five types of soil cover bacteria showed obvious difference in population composition but little difference in evenness and richness. Proteus was the dominant bacteria in the five kinds of soil studied. When halophytes were in the same succession stage, the bacterial communities in soil had a greater similarity. In different succession stages, the bacterial community structure varied greatly.