| Drepanostachyum luodianense(Yi et R. S. Wang) Keng f. is an adaptability bamboo species in Guizhou Karst Mountain. On the IUCN Red List D. luodianense is determined to be critically endangered species. It plays an important roles in soil and water conservation and nutrient balance in Karst Mountain area. To investigate soil microbial diversity, rhizosphere soil of D. luodianense in Luodian country was taken as the research object in this paper. Bacteria, fungi and actinomycetes of D. luodianense rhizosphere soil were separated by dilution-plate method and then picking the difference strains of colony morphology. Then phylogenetic tree was constructed by analyzing 16 S rDNA sequence of bacteria and actinomycetes and ITS rDNA sequence of fungi.Also, related physicochemical properties of D. luodianense rhizosphere soil were studied. Thus providing some theoretical basis and technical support in D. luodianense protection and soil microbial diversity investigation in Karst Mountain area.The main research results were as follows:(1) The rhizosphere soil enzyme research of D. luodianense showed that catalase activity was 8.74 mL KMnO4?g-1?min-1, invertase activity 2.64mg?g-1?d-1, urease activity 0.04 mg NH3-N?g-1?d-1, protease activity 0.10 mg NH2-N?g-1?d-1. Alkaline phosphatase activity was7.97 mg P2O5?g-1?d-1, higher than neutral phosphatase activity, 6.11 mg P2O5?g-1?d-1.(2) The microbe quantity was that bacterial number higher than actinomycetes number, and actinomycetes number higher than fungi number. The average quantity of bacterial, fungi and actinomycetes per gram dry soil was 8.32×107 cfu·g-1,2.32×106 cfu·g-1 and 9.19×105 cfu·g-1,respectively.(3) Totally 41 bacterial strains, 20 actinomycetes strains and 33 fungi strains were isolated by dilution-plate method. The results of 16 S rDNA effective sequences BLAST comparing showed that 41 bacterial strains could be classified as 26 taxon, and actionmycetes could be classified as15 taxon which belonged to Streptomyces. The results of ITS rDNA effective sequences comparing showed that fungi could be classified as 24 taxon. Among the isolated strains 1 fungi strains had only 75 percent similarity with BLAST comparing. It might be a new species or genus.The similarity of the rest were both higher than 97 percent. Shannon-Wiener diversity index(H) of bacterial and fungi were 1.0679 and 2.2180 respectively, abundance index(S) were 7 and 12,evenness index(J) 0.5488 and 0.8926, and dominance index 0.5217 and 0.1295.(4) The 16 S rDNA sequences phylogenetic tree of bacterial and actionmycetes showed that29 bacterial strains accounted for 70.73 percent according to species per taxon belonged to Firmicutes, 11 strains accounted for 26.83 percent belonged to Gammaproteobact, and 1 strains accounted for 2.44 percent belonged to Bacteroidetes among which Bacillus are the dominant.Twenty actionmycetes strains isolated belonged to Streptomyces. ITS rDNA phylogenesis analysiarevealed that among fungi community of D. luodianense rhizosphere soil Ascomycetes group was96.97 percent of total fungi strains. Penicillium, Trichoderma, and Aspergillus which had absolute advantage were 51.51 percent of total strains. Only 1 strains which were 3.03 percent of total strains belonged to Perenniporia.(5) Microorganism total amount of D. luodianense rhizosphere soil was numerous. Bacterial number was preponderant. Fungal diversity index was higher. Actinomycetes only had one genus, but it had many sorts. On a whole, Drepanostachyum luodianense rhizosphere soil had abundant microbial diversity... |
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