Diversity Research On The Effects Of Nitrogen Deposition Of Maize Root Black Soil

Soil microorganism is an important component of soil ecosystem,is one of the important evaluation index of soil fertility.Nitrogen deposition affect soil microbial growth and reproduction,the structure and function change,which affects soil material cycle and flow.In Jilin area due to air pollution caused by nitrogen concentration is higher than south,northwest and Tibetan plateau.Air pollution caused by atmospheric nitrogen deposition quantity increase,will cause soil acidification,NH₄⁺nitrification and NO₃^-leaching,consequences,and further affect the soil microbial diversity,soil fertility and ecological system function,etc.Nearly two years,our country have been on soil microbial community structure and diversity of ecosystem response to study,The relationship of microbial-soil-crop is very complex,and each region soil ecosystem in the differences between different crops and soil heterogeneity is bigger,still need a lot of work to specific studies of jilin province for different atmospheric nitrogen deposition and soil microbial community structure and diversity.In view of the existing problems,there are three main points in this research.?1?The soil samples were collected in the typical black soil corn planting belt,the physical properties of the soil were measured,and the nitrogen elements were used as the variables to set different nitrogen gradients to carry out the biological experiment.The experimental soil was collected,DNA fragments were extracted,the pre primers and the primers were set up in the conservative region of the 16S rDNA sequence,and then the samples were added.This specific sequence,finally obtained on sequencing,sequencing data.?2?A classifier is used to classify the sequencing results to form an operation classification unit?OTUs?,and the operation classification unit is analyzed by PCA and three spline interpolation algorithm.The influence of nitrogen deposition on soil microbial community structure was analyzed by analyzing OTU.The analysis objects include:soil microbial abundance,microbial community structure and dominant bacteria type change trend and regularity.?3?On the basis of 16S rDNA analysis,we do the basic work for the construction of the future macro genome research platform:design the clustering algorithm based on the optimized K-MER frequency,improve the efficiency of microorganism classification,save the resources and time,and use the dominant bacteria found in the biological experiment to carry out the macrogenome simulation experiment.The accuracy rate,recall rate,clustering number and running time are all good.