落叶松枯梢病生防菌的筛选、鉴定及其生物学特性

Screening,Identification and Biological Characteristics of Biocontrol Fungi against Larch Shoot Blight

[目的]为获得落叶松枯梢病的生防菌。[方法]通过对峙实验和发酵液复筛,筛选获得对落叶松枯梢病菌(Neofusicoccum laricinum)具有较强抑制效果的菌株,对筛选得到的菌株进行鉴定,并对其生物学特性展开研究。[结果]筛选得到1株对落叶松枯梢病病原菌有显著拮抗作用的土壤真菌T2,结合形态学以及分子生物学鉴定为钩状木霉(Trichoderma hamatum)。其平板对峙抑菌率达到74.16%,发酵液的抑菌率达到91.29%。发酵液对多种植物病原真菌均具有较强的抑菌作用,对松球壳孢菌、金黄壳囊孢菌、杨灰星叶点霉和立枯丝核菌表现出强抑制作用,抑菌率均为92.00%,对拟枝孢镰刀菌和杨生褐盘二孢菌的抑菌效果较好,分别为79.67%和62.67%。T2能利用多种碳氮源、有广泛的酸碱度适应能力及较高的致死温度。[结论]通过筛选得到的钩状木霉T2对落叶松枯梢病病原菌的拮抗作用显著,抑菌谱广,环境适应力强。本研究可为落叶松枯梢病的防治提供理论研究和基础。

[Objective]The aim of the experiment is to obtain the biological control strain of larch shoot blight.[Method]Strains with strong inhibitory effect on Neofusicoccum laricinum was screened through plate antagonism screening experiments and re-screening with fermentation broth.The screened strains were identified and their biological characteristics were studied.[Result]A soil fungi T2 was screened that had a significant antagonistic effect on Neofusicoccum laricinum,which was identified as Trichoderma hamatum by morphology and molecular biology.Its Inhibition rate of plate experiments reached 74.16%,and fermentation broth experiments reached 91.29%.The fermentation broth had strong inhibition effect on a variety of plant pathogenic fungi,and showed strong inhibition effect on Sphaeropsis sapinea,Cytospora chrysosperma,Phyllosticta populea and Rhizoctonia solani with 92.00%inhibition rate and had better inhibition effect on Fusarium sporotrichioides and Marssonina brunnea with 79.67%and 62.67%inhibition rate,too.T2 can utilize a variety of carbon and nitrogen sources,has a wide adaptability to PH and a high lethal temperature.[Conclusion]The antagonistic effect of T2(Trichoderma hamatum)on Neofusicoccum laricinum is significant,with a wide spectrum of pathogenic inhibition and strong environmental adaptability.This study can provide theoretical research and foundation for the control of larch shoot blight.