瓦雷兹芽孢杆菌FZB42菌株拮抗两种树木病原真菌及其机理研究

镰刀菌和交链孢菌是导致树木病害的两种常见病原真菌,常导致苗圃植物严重的危害和经济损失。瓦雷兹芽孢杆菌FZB42菌株具有高效生防性能和植物促生活性,为进一步探明该菌株的生防机理,首先测试了FZB42对镰刀菌和交链孢菌的抑制效果。在了解该菌株抑制作用的基础上,进一步构建质粒,通过同源重组的方式构建了FZB42的3个抗生素合成缺损菌株(ΔbmyA,ΔfenA、ΔbmyAΔfenA)。对这3个突变株进一步测试表明,FZB42合成的物质bacillomycin D和fengycin是抑制两种真菌生长的重要原因,且这两种物质的拮抗作用具有明显的协同强化效果。

Study on antagonism and mechanisms of Bacillus velezensis FZB42 strain against two species of tree fungi pathogens

Fusarium and Alternaria are two kinds of common pathogenic fungi which can cause tree diseases, especially harmful to nursery plants, and may lead to serious economic loss. Biological control is a promising and environmentally friendly method to control the phytopathogens. Bacillus velezensis FZB42 strain is a plant growth promoting rhizobacterium with potent biocontrol activity. To explore the spectrum of its antagonistic activity, we tested the effect of FZB42 on two fungi species, Fusarium solani and Alternaria tenuis. The results showed that FZB42 could inhibit the growth of both of the species. Further, we constructed three FZB42 mutants(ΔbmyA, ΔfenA and ΔbmyAΔfenA)via homologous recombination. Using the three mutants we demonstrated that bacillomycin D and fengycin synthesized by FZB42 are important to inhibit the growth of the fungi, and the two antagonistic molecules have significant synergistic effect.