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141.
Soil samples were collected from three plots under different land utilization patterns including degradation,farming,and restoration.The abundances of methanotrophs were quantified using real-time polymerase chain reaction(PCR)based on the pmoA and 16S rRNA genes,and the community fingerprint was analyzed using denaturing gradient gel electrophoresis(DGGE)aiming at pmoA gene.Significantly lower 16S rRNA and pmoA genes copies were found in the degradation treatment than in farming and restoration.Higher abundances of Type Ⅰ than those of Type Ⅱ methanotrophs were detected in all treatments.The treatment of farming was clearly separated from degradation and restoration according to the DGGE profile by cluster analysis.The lowest diversity indices were observed in the F(farming plot),suggesting that the community structure was strongly affected by farming activities.There were significantly positive correlations between the copy numbers of pmoA also Type Ⅱ-related 16S rRNA genes and soil available K content.Strong negative and positive correlations were found between Type Ⅰ and soil pH,and available P content,respectively.We concluded that the vegetation cover or not,soil characteristics including pH and nutrients of P and K as a result of anthropogenic disturbance may be key factors affecting methanotrophic communities in upland soil. 相似文献
142.
采用针对16SrRNA和18SrRNA基因的引物,对武汉东湖不同营养水平湖区的浮游生物宏基因组进行凝胶电泳分析(PCR-DGGE)的指纹分析,并探讨宏基因组与环境重金属的关系.结果表明,PCR-DGGE分析共获得82条谱带,其多态率为82.9%,特有谱带占31.7%.I~V站点的谱带分别为36,34,44,50,56条.5个站点浮游生物群落PCR-DGGE指纹结构的聚类分析(UPGMA)分成两大类:I、II、Ⅲ站为一类,IV、V站为一类,这与重金属(铅、铬、汞、镉、砷、铜)浓度对各站点的聚类分枝关系相一致.相关分析显示,变性梯度凝胶电泳(DGGE)谱带所代表的分类单元数(OTUs)与镉、铬的浓度存在较明显的相关性,其相关系数分别为-0.942(P0.05)和-0.928(P0.05). 相似文献
143.
Plankton community composition in the Three Gorges Reservoir Region
revealed by PCR-DGGE and its relationships
with environmental factors 总被引:1,自引:0,他引:1
To explore the relationships between community composition and the environment in a reservoir ecosystem, plankton communities from the Three Gorges Reservoir Region were studied by PCR-denaturing gradient gel electrophoresis fingerprinting. Bacterial and eukaryotic operational taxonomic units (OTUs), generated by DGGE analysis of the PCR-amplified 16S and 18S rRNA genes, were used as surrogates for the dominant "biodiversity units". OTU composition among the sites was heterogeneous; 46.7% of the total bacterial OTUs (45) and 64.1% of the eukaryotic OTUs (39) were identified in less than half of the sampling sites. Unweighted pair group method with arithmetic averages (UPGMA) clustering of the OTUs suggested that the plankton communities in the Xiangxi Rive sites were not always significantly different from those from the Yangtze River sites, despite clear differences in their environmental characterizations. Canonical correspondence analysis (CCA) was applied to further investigate the relationships between OTU composition and the environmental factors. The first two CCA ordination axes suggested that the bacterial community composition was primarily correlated with the variables of NO3^--N, dissolved oxygen (DO), and SiO3^2--Si, whereas, the eukaryotic community was mainly correlated with the concentrations of DO, PO4^3--P, and SiO3^2--Si. 相似文献
144.
Methamidophos was widely used a pesticide in northern China. The potential influences of methamidophos on soil fungal community in black soil were assessed by plate count, 28S rDNA-PCR-DGGE, and clone library analysis. Three methamidophos levels (50, 150, and 250 mg/kg) were tested in soil microcosms. Results from plate count during a 60-d microcosm experiment showed that high concentrations of methamidophos (250 mg/kg) could significantly stimulate fungal populations. DCGE (denaturing gradient gel electrophoresis) fingerprinting patterns showed a significant difference between the responses of culturable and total fungi communities under the stress of methamidophos. Shannon diversity indices calculated from DGGE profiles indicated that culturable fungi in all microcosms with methamidophos treatment increased after 1 week of incubation. However, the diversity indices of total fungi decreased in the first week, as compared to the stimulation of culturable fungi. At the 8th week, however, all the microcosms treated by methamidophos were similar to the control microcosms in community structure as suggested by the Shannon diversity indices for both culturable and total fungi. In contrast, after 1 week the fungal structure of culturable and unculturable both were disturbed to different extent under the stresses of methamidophos by clustering analysis. Clone sequencing analysis indicated the stimulation of pathogenic and unculturable fungal populations by methamidophos treatment, suggetsing potential risks of plant disease outbreak. 相似文献
145.
Analysis of culturable and unculturable microbial community in
bensulfuron-methyl contaminated paddy soils 总被引:1,自引:0,他引:1
To investigate the influence of bensulfuron-methyl(BSM)on culturable microbial quantities and unculturable microbial community structures,conventional and molecular biological methods were employed in five BSM treated soils with three replications,respectively. The results obtained with traditional culture-dependent methods showed that a low-level of BSM had slight and transient effects on culturable microorganisms;nevertheless,high concentration of BSM resulted in a dramatic decrease in bacterial colony fo... 相似文献
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