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通过模拟试验,利用聚合酶链式反应-变性梯度凝胶电泳法(PCR-DGGE),研究了施入不同碳氮有机物料(秸秆、苜蓿、有机肥、尿素)56d后,有机生产系统菜田土壤细菌群落结构的特征。结果表明,常规和有机生产系统土壤的细菌群落结构有明显差异。由DGGE图谱ShannonWiener多样性指数分析得知,有机背景处理的细菌多样性整体高于常规背景处理,且有机生产系统土壤加秸秆处理(OS)多样性最高,加入尿素后细菌多样性降低,相反,加入苜蓿后细菌多样性升高。非加权组平均法(UPGMA)聚类分析将常规和有机背景土壤分为两大族群。DGGE条带测序和系统进化树表明,30个条带归属为Proteobacteria、Acidobacteria、Actinobacteria、Firmicutes、Verrucomicrobia。常规土壤加苜蓿(CA)处理出现的特征性条带B13与有机背景处理的共有条带B28分别与Bacillus属和Pseudomonas假单胞菌属同源性最高。
Through the simulated experiment, the PCR-DGGE was used to study the effects of different carbon and nitrogen organic materials (straw, alfalfa, organic fertilizer, urea) Characteristics of soil bacterial community structure. The results showed that there were significant differences in the bacterial community structure between the conventional and organic production systems. The analysis of ShannonWiener diversity index of DGGE showed that the bacterial diversity of organic background treatment was higher than that of conventional background treatment, and the diversity of soil plus straw treatment (OS) was the highest in organic production system. The bacteria diversity decreased after addition of urea. On the contrary, After adding alfalfa bacterial diversity increased. Unweighted group averaging (UPGMA) cluster analysis divided the conventional and organic background soils into two major groups. DGGE band sequencing and phylogenetic tree showed that 30 bands belonged to Proteobacteria, Acidobacteria, Actinobacteria, Firmicutes and Verrucomicrobia. The common bands B28 and B28 with the common background of soil and alfalfa (CA) treatment had the highest homology with Bacillus and Pseudomonas sp. Respectively.