3株拮抗烟草尖孢镰刀菌的木霉菌筛选鉴定及促生防病效果评价

Screening and identification of three strains of Trichoderma spp.antagonizing Fusarium oxysporum and evaluation of their effects on promoting growth and disease control

【目的】为筛选对烟草镰刀菌根腐病菌具有较好拮抗效果的菌株。【方法】从河南省主要烟叶产区健康烟株根际土壤中,分离纯化对尖孢镰刀菌(Fusarium oxysporum)具有一定拮抗作用的真菌菌株,对筛选出的拮抗菌株进行形态学和分子生物学鉴定,并测定促生作用和防治效果。【结果】分离纯化得到的3株木霉菌分别为棘孢木霉(Trichoderma asperellum)Ta-0101、哈茨木霉(Trichoderma harzianum)Th-0201和毛簇木霉(Trichoderma velutinum)Tv-0207,具有较强的抑菌能力,对尖孢镰刀菌的抑菌率分别为91.24%、84.71%和82.48%。3株木霉菌对烟草种子根长和总长均有显著的促生效果,根长增长率分别为28.89%、25.92%和22.22%,根系活力也显著提高;对烟株最大叶面积和鲜重的促生作用明显,其中棘孢木霉Ta-0101促生效果最显著。3株木霉菌对尖孢镰刀菌的相对盆栽防效分别为78.95%、69.73%和69.73%,均高于70%甲基硫菌灵1000倍液处理的防效。【结论】3株拮抗木霉菌具有较好的抑菌效能和促生防病效果,应用前景良好。

[Background]This study aims to screen out the strains with good antagonistic effects on tobacco Fusarium root rot.[Methods]The fungal strains with antagonistic effect on Fusarium oxysporum were isolated and purified from the rhizosphere soil of healthy tobacco plants in the main tobacco leaf producing areas of Henan Province.The selected antagonistic strains were identified by morphological and molecular biological,and their growth-promoting and disease-control effects were determined.[Results]The three strains of Trichoderma spp.with strong antibacterial ability were identified as Trichoderma asperellum Ta-0101,Trichoderma harzianum Th-0201 and Trichoderma velutinum Tv-0207.Their plate inhibition rates against F.oxysporum reached 91.24%,84.71%and 82.48%,respectively.The three strains of Trichoderma spp.had significant growth-promoting effects on the underground root length and total length of tobacco seeds,and the growth rate of tobacco seedling root length was 28.89%,25.92%and 22.22%,respectively.The root vitality of tobacco seedlings was also significantly higher than that of the blank control group.Their growth-promoting effects on the maximum leaf area and fresh weight of tobacco plants were obvious,in particular the growth-promoting effect of T.asperellum Ta-0101 was the most significant.The pot experiments showed that the relative disease control rates of three Trichoderma spp.strains against F.oxysporum were 78.95%,69.73%and 69.73%,which were all higher than the disease control rateof 70%thiophanate-methyl treated with 1000 times solution.[Conclusion]The three antagonistic Trichoderma strains have good bacteriostatic efficacy,growth-promoting and disease-preventing effects,showing great application prospects.