烟草尖孢镰刀菌拮抗真菌的筛选鉴定及促生作用研究

Screening and Identification of Antagonistic Fungal against Tobacco Fusarium oxysporum and Its Growth Promotion Effect

为获得烟草镰刀菌根腐病拮抗真菌菌株,试验以河南省豫中烟区烟草根际土壤为试材,以主要致病菌尖孢镰刀菌Fusariumoxysporum为主要靶标,采用稀释涂布平板法分离获得土壤真菌371株,平板对峙培养法测定获得1株具有明显抑制效果的拮抗菌株,利用形态学和分子生物学的方法将其鉴定为棘孢木霉Trichoderma asperellum Tr-0111。抑制效果测定表明,该菌株对尖孢镰刀菌的抑制率最高可达93.13%,对根串珠霉菌、拟茎点霉、链格孢菌等其他8种烟草病原菌均具有较强的抑制效果。促生作用测定结果表明,菌株发酵液使烟草种子萌发率提高5.34%,烟苗根长增长率为62.39%,对盆栽烟草的最大叶面积和地上部鲜重也具有显著的促生效果。为进一步相关机理的研究和生防菌剂的研制奠定了基础。

In order to obtain the antagonistic fungal strains against tobacco Fusarium root rot, 371 fungal strains were isolated from the tobacco rhizosphere soil in the tobacco area of Henan Province by dilution coating plate method. One Trichoderma strain with obvious inhibitory effect against F. oxysporum was obtained by the plate confrontation culture method, and was identified as T. asperellum Tr-0111 by morphological and molecular biology methods. Tr-0111 strain had a maximum inhibitory rate of 93.13% against F. oxysporum, and also had a strong inhibitory effect on 8 other tobacco pathogens, such as Thielaviopsis basicola, Phomopsis sp., Alternaria alternata, etc. The growth-promoting effect test showed that the fermentation broth of the strain increased the germination rate of tobacco seeds by 5.34%, and the increase rate of root length of tobacco seedlings was 62.39%.It also had a significant growth-promoting effect on the maximum leaf area and fresh weight of the above-ground part of potted tobacco. The results laid the foundation for further research on the related mechanisms and development of biocontrol agents.