不同土地利用方式下滨海盐土细菌多样性变化

Changes in Bacteria Diversity of Coastal Saline Soils under Different Land Use Patterns

采用细菌16S rDNA的PCR-RFLP技术,以天津滨海盐土为材料,研究农田(S1和S2)、菜地(S3和S4)和果园(S5)3种土地利用方式下5个土样的细菌多样性。结果显示,基于限制性内切酶HhaⅠ和RsaⅠ的PCR-RFLP分析分别得到93、165、115、158和163个酶切类型,除S1和S3存在一个共同的优势类型,比例分别为33.70%和19.50%外,其余样品没有明显的优势类型;采用α多样性测度对试验结果进行统计分析表明,土壤细菌的多样性指数(H′、Ds)和物种丰富度指数(dMa)均为S2>S5>S4>S3>S1,可见不同土地利用方式下,细菌多样性发生变化;基于16S rDNA核酸序列构建的系统发育树表明,测序的26个序列分属于8个类型,其中酸杆菌所占比例最大(34.62%),其次为变形菌纲(23.08%)、厚壁菌门(15.38%)和放线细菌(11.54%),另外有少量硝化螺旋菌纲、绿弯菌纲、芽单胞菌纲和浮霉菌纲的克隆。可见,不同土地利用方式下,滨海盐土土壤的细菌多样性丰富且彼此间存在显著差异。

The bacteria diversity of coastal saline soil in Tianjin was studied by PCR-RFLP based on 16S rDNA.The three land use patterns were farmland（S1 and S2）,vegetable plot（S3 and S4） and fruit orchard（S5）.The 16S rDNA was digested by HhaⅠ and RsaⅠ.The results showed there were 93,165,115,158 and 163 restriction endonuclease types respectively among five soil samples.A same preponderant RFLP type exists between S1 and S3,whose ratio were 33.70% and 19.50% respectively,while no dominant type exists in S2,S4 and S5.The α indices（H′,Ds and dMa） changed in different soils with an order of S2S5S4S3S1.Phylogenetic tree of 16S rDNA sequences showed that the sequenced clones fell into eight major lineages within the bacteria domain.Among them,members of the Acidobacteria were dominant group,accounting for 34.62%,followed by proteobacteria,firmicutes and actinobacteria division with 23.08%,15.38% and 11.54%,respectively.Nitrospira,chloroflexi,gemmatimonadetes and planctomycetacia were less well represented.Our study revealed that the diversity of bacteria in coastal saline soil was extensive,and the land use patterns had a significant impact on bacteria diversity.