Isolation And Study On Promoting Fuction From Rice Endophytic Bacteria And Polyphasic Taxonomy Of A Few New Strains

This study based on the materials from rice seeds and roots of RMV、RWF、RRP、RRG, with a30-year long-term positioning history from the National Field Research Station of the farmland system,Qiyang of Hunan Province, traditional pure culture methods isolated endophytic bacteria from rice seeds and roots, study the diversity of microorganism, and strain screening for promoting ability. The new taxa bacteria was identified by the method of polyphasic taxonomy.Dilution coated plate method isolated and purified endophytic bacteria of the different green manure crop rotation.The purified strains of 16 S rDNA was amplified with the aid of bacterial universal primer and amplified by means of PCR. 256 strains isolated from rice seeds, including 42、102、58 and44 endophytic bacteria isolated from RMV, RWF, RRP, RRG respectively, were classified into 23 species, 39 genera, the genus Pseudomonass is the predominant genus. 360 strains isolated from rice roots, including 55, 173, 72 and 60 endophytic bacteria isolated from RMV 、 RWF 、 RRP 、 RRG respectively, were classified into 31 species, 50 genera, the genusHerbaspirillum is the predominant genus.Isolated endophytic bacteria of rice seeds from rice soup、Ashby、TSA and 1/4R2 A four different mediums, the results showed that, the number of endophytic bacteria on the RMV was rice soup >Ashby >TSA >1/4R2 A, on the RWF was 1/4R2A> TSA > Ashby > rice soup, on the RRP was 1/4R2A>Ashby > rice soup > TSA, on the RRG was 1/4R2A> rice soup > Ashby > TSAPreliminary screening functional plant growth of selecting 179 strains from predominant species were analyzed by the method of qualitative or quantitative. Results showed that there were 80, 64, 93 strains with phosphate-solubilizing activity, siderophore-producing activity and IAA producing activity.Through the secondary screening of 40 strains, the results showed that there are 28 strains inhibited Fusarium moniliforme and 5 strains with nitrogenase activity. Selected 17 strains for the tube promoting capacity evaluation test based on above results. Results showed that the height, fresh weight and dry weight of rice in the 17 handled strains were all higher than control group. Difference analysis by SPSS software, the results showed that the height, fresh weight and dry weight of rice of 4 strains were outstanding difference than in control group. Than prepared to conduct field experiments with above 4 strains.Polyphasic taxonomy with four strains ZYY112, 1ZS3-5, NEAU-ST5-5 and NEAU-ST5-21 isolated from rice root 、 rice rhizosphere soil and saline-alkaline soils in Songnen Plain, from phenotypic features 、chemotaxonomic features and genotypic features. Including morphological feature、physiological characteristics、biochemical character、nuritional requirement、fatty acid analysis、respiratory quinine analysis、polar lipid analysis and the phylogenetic analysis of 16 S r DNA and housekeeping gene sequence, DNA G+C mol%, DNA-DNA hybrid homology. Results showed that strain ZYY112 belong to Novosphingobium genus, strain 1ZS3-5 belong to Paenibacillus genus, NEAU-ST5-5 and NEAU-ST5-21 were all belong to Pseudomonas genus, and they were all had a significant difference with their own closest species. At last, we confirmed they were the new members of their respective genus.