| Poplar as a major fast-growing species in China,and in the area of plantation and timber processing increasing attention.Currently,sapstain of poplar wood has caused tremendous losses in the wood processing industry,biological control of poplar sapstain fungi is studied to be very real economic significance.A methods of the tissue and induced isolation were used in this study and 14 isolates sapstain fungi were got from the different sources,sapstain ability determinated and on the morphology of the identification and selection of the 14 strains for a number of biological characteristics;selected a representative of the six kinds of sapstain fungi as a test for the strain,through the confrontation between the flat and fermented liquid antibacterial test,screening antagonistic to the objectives of a change control of indoor wood,and preliminary study of the principles of antimicrobial.Tests include the following aspects.1.Isolated from 14 different sources of the sapstain,fungi,the morphological identification attributable to eight species,namely Lasiodiplodia theobromae(Pat.)Griff. & Maubl.,Lasiodiplodia rubropurpurea Burgess.& Barber.,Lasiodiplodia crassispora Burgess Barber & Pegg.,Fusarium decemcellulare Brick.,Ceratocystis adiposa(Butl.) Moreau.,Chalara urceolata Nag Raj & W.B.Kendr.,Dothiorella gregaria Sacc.and Alternaria sp.respectively,Alternaria of the two strains can not be identified to species。2.Wood sapstain fungi test showed that poplar wood sapstain caused by Lasiodiplodia theobromae,L.rubropurpurea,L.crassispora,they are the most impotanct sapstain fungi and very fast growing,Alternaria sp.as follow,others species are the slowest in wood satain and myceliun gorwth.3.Research of Sapstain fungi of biological characteristics shows that 14 strains are extremely sensitive for acid conditions,the majority strains stop growth in pH2,the suitable range of pH valumes are from 5 to 9,some species can grow under pH11. Temperature tests showed that the majority of sapstain fungi is very sensitive to temperature,the suitable range of temperature are from 10～35℃,the optimum temperature of Alternaria sp.,Dothiorella gregaria,and Fusarium decemcellulare, Ceratocystis adipose to be from 25℃to30℃,Lasiodiplodia theobromae,L.rubropurpurea, L.crassispora from 30℃～35℃;The Fluorescent can promote mycelium growth and formation of fuiting bodies of Lasiodiplodia theobromae,L.rubropurpurea,L.crassispora, Ceratocystis adipose and Dothiorella gregaria in incubation,Fusarium decemcellulare can produce more conidia mass.The same strain from different regions and hosts need to different pH,temperature and light condition in laboratory.4.204 bacterial strains isolated from soil and healthy poplar wood,and use of confrontation between the fungus and bacterium in plate for nine antagonists,and tested six species of sapstain fungi of confrontation can create inhibitory transparent zone with the growth rate of re-screen,antagonistic bacteria B4 inhibitory effect to be the best and the inhibition rate of 90%over,as the object potential biocongtrol bacterium need to further study.5.Through the control test of wood sapstain in laboratory,sap-stain fungi were inoculated on healthy poplar wood weneer of using bacteria broth treatment after 10 days the wood did not change color,while the control group wood occur with varying degrees of sapstain fungi,Sapstain fungi grow around wood and wood chips,but treated wood chips no any mycelium growth.6.The studies on B4 strains antibacterial principle showed that antagonism substance from bacterium B4 strain can inhibit mycelim growth and germination of spores,and the filtrate after fermentation can result in mycelial deformation,protoplast spill,the spores does not germinate,swollen and form a round spherical bubble. |
