Study On The Diversity And Application Of Rhizobium Bacteria In Main Peanut Producing Areas Of Liaoning Province

This study collects two kinds of soil in fuxin city and changwu county of Liaoning province,planting nine kinds of legumes:Clover,broad Bean,alfalfa,soybean,peanut,cowpea,Tianjing,mung bean and ziyunying,which proved the diversity of rhizobium in main peanut producing areas.The 23 strains of peanut rhizobia isolated and purified are reconnected and the physiological and biochemical indexes are determined.The subsequent use of 16S r DNA further demonstrats the diversity of rhizobia isolated in the two regions,screening the excellent strain A5 for inoculation under different nitrogen treatments,conducting field application studies.Finally,the best treatment for the test and yield results is N_2/3A5.From the characteristics of growth generation,acid-base production and so on,it can be preliminarily determined that the strain to be tested is slow rhizobium;Through the numerical classification,it is found that the 23 strains under test have80%similarity,and the strains are grouped into 4 groups.Group IV has more strains,and multiple strains from two soils are isolated in this group;Group II,Hequn,is a group of three strains,including strains in two regions;It is proved that different regions have the same rhizobium and have diversity.Through the analysis of the 16S r DNA sequence,the results show that the tested strains belong to Bradyrhizobium,indicating that the dominant rhizobium strain in Liaoning Province is Bradyrhizobium.The 16S r DNA gene is analyzed and a phylogenetic tree is established.The strains to be tested were classified into 5 taxa.In combination with the above,it can be seen that the distribution of 23 strains has certain regularity.The planting environment,soil fertilizer efficiency,geographical location and other factors affect the diversity and distribution of rhizobium.Test set eight processes,Analysis of soil ammonium,nitrate nitrogen,quick-impact phosphorus,quick-impact potassium content and related enzymes in the soil of 0-10cm,10-20cm,20-30cm during the flowering and pod periods,and the determination of various organs of peanut plants.Total nitrogen,total phosphorus,The results of the determination of total potassium content showed that the remaining seven treatments are significantly different from those of CK.The treatment effect is better than that of uninfected nitrogen fertilizer.Ammonium,nitrate nitrogen,available phosphorus,and available potassium content gradually increase with the soil layer,and there is a decreasing trend;The content of total nitrogen and total phosphorus in peanut plants is higher than that of stem,and the content of total potassium is higher than that of leaf.Analysis above,only to achieve a certain proportion of nitrogen application and application of high-efficiency fertilizer,can really reduce the amount of fertilizer in agriculture.In the field experiment of this study,when the same amount of nitrogen fertilizer is used,the number of peanut root tumors is changed compared with the uninoculated ones.The number of root tumors treated without fungicides in each treatment do not change much,but the number is relatively small.The results show that the number of peanut rhizobia from the local area is relatively small,and inoculation of root tumors is beneficial to improving the nitrogen fixation of peanut plants.The test results and yield results of peanut field test are analyzed during the mature period.The results show that the measurement indexes of each treatment are significantly higher than those of CK.In the examination,the results of the indicators of N_2/3A5 are more prominent,followed by N_1/3A5;At the time of the yield survey,it is proved that the treatment of N_2/3A5 have the highest yield and the most obvious effect,24.59%more than the control of Gaochu,and 15.35%more than the uninfected bacteria;The second is the treatment of N_1/3A5,which is 16.19%higher than that of Gaochu,and 9.1%more than that of uninfected bacteria.In combination with the above,bacterial treatment is very important in increasing flower production,and the combination of rhizobium and nitrogen fertilizer in the treatment of N_2/3A5can better increase peanut production.