The Relations Between Function Bacteria Diversity From Rhizosphere Soil Of Eucalyptus And Against Ralstonia Solanacearunm

With the rapid development of eucalyptus industry in China, the contradiction between lumber forest products supply and demand were alleviated effectively, but the pooly operating, technology and other aspects of the management relating to the eucalyptus industry resulted in the emergence of soil fertility decline, plant and insect pests diseases. These issues should be taken into accounted for the sustainable development of the eucalyptus industry.Through the research of the relationship among eucalyptus rhizosphere function, bacteria diversity, bacterial wilt pathogen and eucalyptus species interaction, this paper tried to disscuss the pathogenesis of eucalyptus bacterial wilt, search for the beneficial bacteria that enhance the soil fertility and inhibit bacterial wilt effectively. The main results are summarized as follows:(1)50strains were separated and purified from the plantation soil of eucalyptus rhizosphere, among them, Y1Y2.Y5. Y8. Y9. Y10and Y13were inorganic phosphorus bacteria, W1W4. W6. W9. W11W16. W17, W18. W28. W29were inorganic phosphorus bacteria, AN3. AN6. AN8. AN11. AN13, AN14, AN16. AN17, AN18, AN19, AN20, AN21. AN22, AN24, AN26, AN28, AN31, AN33, AN34, AN35, AN38, AN40,AN41were ammonifying bacteria and F2. F3, F32, F33. F37. F38. F40. F41. F45. F48were denitrifying bacteria.(2) The number of organophosphorus bacteria, inorganic phosphorus bacteria, ammonifying bacteria and denitrifying bacteria in rhizospheric soil of E. urophyllaxE. grandis^E. grandisxE. urophylla. E. camaldulensis. E. grandis. E. saligna. E. dunnii. E. urophyllaxE. camaldulensis. E. pellita were studied by MPN dilution method. The results showed the number of ammonifying bacterial in rhizosphere soil of eucalyptus is E. urophylla×E. grandis>E. grandis×E. urophylla>E. camaldulensis>E. grandis>E. saligna>E. dunnii>E. urophylla×E. camaldulensis>E. pellita. The number of denitrifying bacterial is E.grandis>E. grandis×E. urophylla>E. saligna>E. dunnii>E. camaldulensis> E. urophylla×E. camaldulensis> E. pellita>E. urophylla×E. grandis. The number of organophosphorus bacterial is E. grandis×E. urophylla>E. urophylla×E. grandis>E. saligna>E. pellita>E. dunnii>E. urophylla×E. camaldulensis. The organophosphate bacteria were not detdected from the rhizosphere soil of E. grandis and E. camaldulensis. The number of phosphorus bacterial is E. grandis×E. urophylla> E. grandis>E. urophylla×E. grandis>E. saligna>E. camaldulensis>E. dunnii>E. pellita>E. urophylla×E. camaldulensis.(3) With the filter paper method, the anti-bacterial activities of functional bacteria against Eucalyptus bacterial wilt showed that9strains, includingY5^Y8. W9. W11. AN20. AN21. AN28. AN35and F38exhibited inhibitory effect.(4) The tolerance experiment of the extract from eucalyptus litter against function bacteria showed that microbial population structure is extremely remarkable influenced by the concentration of1～10-2mg/mL of E.dunnii. E.grandis and E.camaldulensis, within the concentration range10-2～10-4mg/mL, the extract had little effect.In1～10-4mg/mL, the extract of E.dunnii could promote the growth of eucalyptus bacterial wilt, but the effect were weaken with the declined of extract concentration, the E.grandis in1～10～1mg/mL, E.camaldulensis in1～10-2mg/mL could promote the growth of bacterial wilt also, but no significant difference were observed between different concentration.(5)The experiment of beneficial effect of eucalyptus litter on wilt pathogens, antagonistic bacterial showed that E.dunnii could promote the growth of wlland F38; E.grandis did on AN35and F38and E.camaldulensis on W11. AN20. AN28and F38.(6) The volatile components of eucalyptus litter were determinated by the GC-MS technology. The results show that the main composition of E. urophylla, E. camaldulensis. E. pellita> E. urophylla, E. grandis. E. saligna, E.camaldulensis and E.dunnii were Eucalyptcl. borneoK a-terpinok aromadendrene^phellandrene^fenchol> g-terpinene. pinene. carene. a-gurjunene. b-selinene, geraniolene. Eremophilene and so on. Eucalyptol is common chemical composition of the E. urophylla, E. camaldulensis. E. pellita.E. urophylla, E. grandis^E. saligna. The significant difference were observed among the the major volatile oil content of the six eucalyptus litter.