拮抗烟草疫霉菌的木霉菌株筛选鉴定及防病促生作用研究

为了获得对烟草黑胫病菌具有较好拮抗效果的木霉菌株，从河南省各烟区烟草根茎类病害发生较重烟田健康烟株的根际土壤中共分离获得疑似木霉菌28株，通过平板对峙培养，筛选出菌株XYPQ-1、ZMD-1和XYLS-5对烟草疫霉菌具有较强抑制作用，5 d后抑菌率达90%以上。利用分子生物学方法分别将其鉴定为绿木霉菌（Trichoderma virens）、拟康宁木霉菌（Trichoderma koningiopsis）和近渐绿木霉菌（Trichoderma paraviridescens）。对其代谢物抑菌活性及防病促生效果进行了初步研究，结果表明，3种木霉菌产生的挥发性和非挥发性代谢物均对疫霉菌具有明显的抑制作用，其中XYLS-5的抑制效果最好，处理后5 d，其挥发性和非挥发性代谢产物的抑菌率分别达61.71%和100.00%。3种木霉菌对烟草黑胫病均具有较好的室内防效，其中XYLS-5的防效最高，达80%以上，且具有促进烟草种子萌发和根系生长的作用，可作为烟草黑胫病生物防治的拮抗菌加以开发应用。

Screening,Identification of Antagonistic Trichoderma spp. against Tobacco Black Shank and Its Growth Promotion Effect on Tobacco

In order to acquire Trichoderma strains with preferable inhibitory effect on tobacco black shank, twenty-eight strains of Trichoderma were isolated from rhizosphere soil of uninfected tobacco plants in Henan province. The strains of XYPQ-1, ZMD-1 and XYLS-5 exhibiting better inhibitory effects on Phytophthora nicotianae were screened out by plate confrontation, with inhibitory rate of more than 90% after five days. Based on molecular biological analysis, the three Trichoderma strains were identified as Trichoderma virens, Trichoderma koningiopsis and Trichoderma paraviridescens, respectively. The antifungal activity of metabolites and the antagonistic effect were also studied. The results showed that both the volatile and non-volatile metabolites of the three Trichoderma spp. had inhibitory effect on P. nicotianae, and the strain XYLS-5 exhibited the optimal inhibitory effect, with its inhibition rate of volatile and non-volatile metabolites achieving 61.71% and 100.00%, respectively. The three Trichoderma strains could control tobacco black shank in greenhouse, among which strain XYLS-5 performed the optimal control efficiency exceeding 80% and could promote seed germination and root growth of tobacco. Results indicated that strain XYLS-5 can be used as antagonist for controlling tobacco black shank.