Research On Tobacco Fields Microbial Diversity Of Different Ecological Condition And Cultivation System

This article uses Bead beating method to extract total DNA in different ecological condition and cultivation system, touchdown PCR was performed using 16S rDNA V3 region consensus primer set, and the products were analyzed by denaturing gradient gel electrophoresis (DGGE). The main results are shown as follows:The DNA-extracting method of Bead beating not only protected DNA from mechanical damage but also ensured the DNA's quality, and the extracted DNA could be directly used in follow enzyme reactions.Single use of organic fertilizer had the biggest effect on soil microbial diversity. Using 75% inorganic fertilizer with 25% organic fertilizer helped increasing soil microbial diversity rapidly. The microbial diversity reduced in single inorganic fertilized rhizosphere soils, meanwhile, increased microbial diversity of non-rhizosphere soils.During the growth phase of tobacco, the change of microbe population in continuous cropping soil was substantial, and the microbial diversity of continuous cropping soil was the highest, soil which interval year is 2 was the second. The microbial diversity in soil which interval year 4 declined. In soils of Altitude 746 meters, the microbial diversity of non-rhizosphere soils higher in the vigorous growing stage than in the harvest growing stage, however, it was completely contradict in rhizospheresoils. The microbial diversity increased from the vigorous growing stage to the harvest growing stage in both soils of Altitude 933 meters and Altitude 1095 meters, and the microbial diversity in Altitude 1095 meters soil was larger than in Altitude 933 meters. Similarity between non-rhizosphere soil and corresponding rhizosphere soil descends as the altitude ascends. The lower the altitude of soil sample, the larger the similarity between vigorous growing stage and harvest growing stage.The microbial diversity of yellow-brown non-rhizosphere soil was the lowest in the transplanting stage, however, rhizosphere soil's microbial diversity was the highest. Microbial diversity of yellow-brown soils > purple soils. The similarity of yellow-brown soils between vigorous growing stage and harvest growing stage was larger than purple soils.