【作者】 席刚俊；

【导师】 韩正敏；

【作者基本信息】 南京林业大学 ， 微生物学， 2008， 硕士

【摘要】 杨树作为我国主要的速生树种,在种植及板材加工领域越来越受重视。目前,杨木板材生物变色已给木材加工业造成了巨大的损失,研究杨木变色菌及其生物防治具有很现实的经济意义。本研究采用了组织分离法和诱导法分离到来源不同的变色菌14株,对这些菌株进行了变色能力测定及形态学鉴定,并做了生物学特性研究;选取了6种有代表性的变色菌作为供试菌株,通过平板对峙法、发酵滤液抑菌试验进行了生防菌的筛选,进行了室内木片变色防治试验,并初步研究了拮抗菌株的抑菌机理。内容如下:1.分离到14个来源不同的变色菌株,经形态学鉴定归属于2亚门3纲3目6属7种,分别为可可球二孢[Lasiodiplodia theobromae(Pat.)Griff.&Maubl.]、Lasiodiplodiarubropurpurea Burgess.&Barber.、Lasiodiplodia crassispora Burgess,Barber&Pegg.、多隔镰刀菌(Fusarium decemcellulare Brick.)、长喙壳[Ceratocystis adiposa(Butl.)Moreau.]、鞘孢菌(Chalara urceolata Nag Raj&W.B.Kendr.)、群生小穴壳菌(Dothiorella gregaria Sacc.)及链格孢(Alternaria sp.),其中链格孢的两个菌株未鉴定到种。2.木片变色试验显示,球色单隔孢属(Lasiodiplodia theobromae,L.rubropurpurea,L.crassispora)的变色菌引起杨木变色的速度最快,链格孢(Alternaria sp.)次之,其余的几种菌变色较慢。3.变色菌生物学特性研究表明,14个菌株对极酸条件都比较敏感,在pH2大部分菌株停止生长,适合生长的pH范围大致为在5～9,在强碱性条件pH11下都能生长。温度试验表明,大部分变色菌对温度非常敏感,生长的温度范围一般在10℃～35℃,其中,链格孢、群生小穴壳、多隔镰刀菌、鞘孢菌和长喙壳其最适生长温度范围为25℃～30℃,而球色单隔孢属(Lasiodiplodia theobromae,L.rubropurpurea,L.crassispora)的三种菌最适生长温度范围为30℃～35℃;光照试验结果表明,光照对Lasiodiplodia theobromae、L.rubropurpurea、L.crassispora、长喙壳和群生小穴壳的生长有促进作用,试验中还发现在全光条件下有利于球二孢产生子实体,也有利于多隔镰刀菌产生粘性孢子团。试验证明分离至不同地区和寄主的相同菌株,其在不同pH、温度及光照下表现出一定的差异,这表明同一菌株在不同的环境下生长,其生物学特性也会发生一些变化。4.从土壤和未变色杨木组织中分离到204株细菌,并采用平板对峙法筛选出9株拮抗菌,它们与6种供试变色菌对峙都能形成拮抗透明带:用生长速率法复筛,拮抗菌B4抑菌效果最好,抑菌率都在90%以上,将其作为进一步研究的对象。5.通过室内木片变色防治试验,用发酵液处理过的木片接种变色菌10d后,木片未发生变色,且接种的菌饼出现了萎缩;而对照组中的木片均发生了不同程度的变色,变色菌在木片上和木片周围生长,但在靠近处理组木片的一侧菌丝生长也受到了抑制。6.B4菌株抑菌机理研究表明,B4菌株的拮抗物质可抑制变色菌菌丝生长和孢子萌发,用发酵滤液处理后,变色菌菌丝变形,原生质外溢,孢子不萌发或萌发产生不正常的芽管或孢子畸形、肿大,形成圆球状泡。更多还原

【Abstract】 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.更多还原