Diversity Of Bacteria And Archaea In The Soil Of Protected Land

With the expansion protected area in China, the shortcomings of the protection cultivation measures gradually emerged.cultivation for many years, excessive use of fertilizers, high temperature and humidity, evaporation and other major features, soil formation contrary to the physical, chemical and biological properties. Resulting in the acidification of soil compaction, soil nutrient imbalance, soil salinization, soil-borne diseases a serious outbreak, soil microbial flora imbalance in the soil root-knot nematode damage and other serious problems. Soil Microbial in the soil ecosystems have an irreplaceable role .So that soil Microbial imbalance in will directly undermine the biological balance, product a serious impact on soil environment and agricultural production.In this study, Application of 16S rRNA gene cloning library technology research in the protection of cultural facilities to study the district of soil microbial community structure and change of the composition. To provide a theoretical basis for the diversity of soil microorganisms in the soil and the impact to the plants. There is great significance for the sustainable the development of protection agriculture and other issues.Nitrogen is essential nutrition element for plant growth, and a major limiting factor for soil productivity. Soil nitrogen cycle imbalance will affect other important biogeochemical cycles, and global environmental change. Protection of the cultural facilities changed the ecological environment of its coverage of the soil, high temperatures, high humidity, high-fat and higher CO2 concentration, that will directly affect the community structure of the ammonia-oxidizing bacteria and Archaea which are closely related to the nitrogen cycle. Therefore application of ammonia-oxidizing Bacteria and Archaea amoA gene library research the impact of the structure and the composition of soil microbial community in the protection of cultural facilities under the conditions of soil root knot nematode disease occurred areas, for further study nitrogen cycle of farmland and global environmental change is of great significance. The main results were as follows:1.The soil Bacteria and Archaea amoA 16S rRNA gene libraries were generated for the soil of protected cultivation and open field, the diversity and phylogenetic analysis of Bacteria and Archaea in the two soil showed that:(1) Application ARDRA technology on both the soil bacteria and Archaea diversity analysis showed that the bacteria and archaea community composition and diversity in the open field with health of soil are higher than the protection of cultural facilities root knot nematode took place.(2) These observed variations in community composition were statistically compared using∫- Libshuff. The Phylogenetic analysis and comparative analysis showed that: the department of community composed of two soil bacteria is no significant differences, but in the protection of cultural facilities root knot nematode took place,soil Agrobacterium has a larger proportion than the open field . Agrobacterium tumefaciens which can cause cancer of plant has the large numbers. the number of clones of soil Agrobacterium is 3.66 times than the open field; The P values of the two Archaea cloning library are 0.0000 (P <0.05), that calculate with the∫-Libshuff. So that the two Archaea clone libraries exists significant differences between them .The number of clones of the Euryarchaeota in the tow libraries of Archaea 16S rRNA gene are very difference, respectively 19.0 percent and 1.92 percent.(3) Bacteria and archaea diversity of the two soil analysis showed that the soil in the open field were higher than the protection land of biodiversity components. Different types of soil micro-organisms are very different functions, so the reduction of microbial diversity, will directly affect the different functions of the various micro-organisms, and the interaction between themselves. Thus the various soil nutrient cycle, the decomposition of organic matter, plant nutrient absorption and the growth and development will have serious adverse effects.2.The soil Bacteria and Archaea amoA gene library were generated for the soil of protected cultivation and open field, the two soil ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) diversity of the phylogenetic analysis showed that:(1) To assess AOA and AOB diversity within the soil of protected cultivation and open field, the OTUs predicted by richness and Chao1-estimated richness. the analysis showed that: the diversity of ammonia-oxidizing bacteria (AOA and AOB) in the open vegetable fields are significantly higher than the soil of protected cultivation.(2) These observed variations in community composition were statistically compared using∫- Libshuff. The phylogenetic analysis and comparative analysis of the libraries showed that: the P value of two ammonia-oxidizing archaea (AOA) clone libraries are 0.0000 (P <0.05). there is significant differences between the two libraries. the P value of two ammonia-oxidizing bacteria (AOB) clone libraries are 0.0000(P<0.05). two clone libraries also significantly different. All this show that the composition of the community of the AOA and AOB that related to the nitrogen cycle are significant change.(3) the diversity of ammonia-oxidizing bacteria and archaea were significantly higher than that of the protection land. So speculated that because of ammonia-oxidizing bacteria and archaea the diversity of the lower under the conditions of the protected land, the nitrification is likely to become fragile and sensitive. And are susceptible to interference, reduced the efficiency of nitrification, weakened the ability to adapt to the complex environment significantly. Then serious impact nitrogen cycle of normal operation in soil. Thus further to adverse affect soil nutrient cycling and soil ecosystem balance, plant growth and development.