木霉菌对白腐真菌所致木材腐朽防效研究

Study on the Control Effect of Trichoderma on Wood Decay Caused by White Rot Fungi

筛选有效抑制白腐真菌生长并降低其对木材腐朽能力的生防菌株,为白腐真菌所致木材腐朽的生物防治提供新思路。以樟子松(Pinus sylvestris)倒木中分离纯化的3株木霉(Trichoderma spp.)作为生防菌株,利用离体对峙培养法测定分离菌株对多种白腐真菌的拮抗效果,结合形态学、分子生物学和系统进化树分析对拮抗效果较好的真菌进行鉴定,并通过检测生防真菌的代谢产物及其与白腐真菌菌丝间的作用关系初步探究其生防机制,最后利用质量损失法检测该生防菌株防治白腐真菌对樟子松木材腐朽的能力。结果表明:筛选得到1株有较好拮抗效果的生防真菌SF2,对峙培养8 d时,该菌株对5种白腐真菌的抑菌率从高到低排序为白囊耙齿菌(Irpex lacteus)>一色齿毛菌(Cerrena unicolor)>粗毛拟革盖菌(Coriolopsis aspera)>彩绒革盖菌(Coriolus versicolor)>裂褶菌(Schizophyllum commune);经过形态观察、ITS1/ITS4 DNA序列扩增比对和系统发育树分析,发现SF2菌株属于长枝木霉(Trichoderma longibrachiatum);生防菌对白腐真菌的抑菌机理显示,菌株SF2可以通过重寄生以及分泌代谢产物对白囊耙齿菌产生抑制;木材接种试验结果表明,接种SF2菌株能显著减少白囊耙齿菌所致樟子松木材质量损失,减少率达46.43%。综上,本研究筛选鉴定的SF2菌株为长枝木霉,其对白腐真菌生长及其所致木材腐朽具有一定的防治效果,本研究为木材白腐病的生物防治奠定理论基础。

In order to screen bio-control strains which could effectively inhibit the growth of white rot fungi and reduce their ability to decay wood,a new idea was provided for the biological control of wood decay caused by white rot fungi.Three strains of Trichoderma isolated from fallen wood of Pinus sylvestris were used as biological control strains.The antagonistic effect of the isolated strains against several white rot fungi was determined by in vitro antagonistic culture method.The strain with good antagonistic effect were identified by morphology,molecular biology and phylogenetic tree analysis.And their biocontrol mechanism was preliminarily explored by detecting the metabolites of bio-control fungi and and their relationship with those of pathogenic white rot fungi,and the ability of biocontrol strain against wood decomposition by white rot fungi was tested by mass loss method.The results showed that the biocontrol strain SF2 with better antagonistic effect was obtained by screening.After 8 days of confrontation culture,the inhibition rate of the strain against five pathogenic white rot fungi was ranked:Irpex lacteus>Cerrena unicolor>Coriolopsis aspera>Coriolus versicolor>Schizophyllum commune.The strain was identified as Trichoderma longibrachiatum by morphological observation,ITS1/ITS4 DNA sequence alignment and phylogenetic tree analysis.During the confrontation culture,strain SF2 could inhibit I.lacteus by parasitism and metabolite production.The results of wood inoculation test showed that the inoculation with SF2 strain could significantly reduce the weight loss of P.sylvestris wood caused by I.lacteus,with a reduction rate of 46.43%.In summary,the SF2 strain in this study was T.longibrachiatum,which had good bio-control application value.This paper provided a basis for the bio-control of wood white rot.