黄瓜枯萎病拮抗芽孢杆菌的筛选、鉴定及其生防潜力.

Cucumber Fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum seriously affects the sustainable development of the cucumber industry. In order to obtain high-efficiency antagonistic Bacillus spp. against cucumber Fusarium wilt and clarify its growth-promoting effect, hte biocontrol strain with a strong antagonistic effect against F. oxysporum were screened from Bacillus with a certain resistance to Fusarium solan, and its morphological, physiological and biochemical, genetic characteristics and plant growth-promoting characteristics were evaluated. The results showed that strain N1、N3 and N6 presented significant inhibitory effects on F. oxysporum, with inhibitory rates of 77.71%, 75.94% and 74.76%, respectively. Three strains were all identified as Bacillus velezensis, all the three strains showed releasing potassium ability, and produced protease, chitinase, pectinase and siderophores. In the seedlings disease-prevention and growth-promotion test, the disease index of inoculated strain N1, N3 and N6 significantly reduced, the control efficiency was 41.93%, 20.97%, and 66.13% respectively on the 18th day after inoculation. Inoculation with N1, N3 and N6 strains effectively promoted the growths of cucumber seedlings compared with single inoculation of F. oxysporum f. sp. treatment, including plant height, stem thickness, leaf area, chlorophyll content and aboveground and subsurface fresh weight, the growth promoting effect of N6 treatment was the most significant. It increased by 21.56%, 56.13%, 47.95%, 76.18%, 222.89% and 70% respectively. Compared with the control, the growth characteristics of treated plants significantly decreased except for the fresh weight of underground parts. Under inoculation F. oxysporum f. sp., the addition of N6 significantly increased the stem thickness and aboveground fresh weight. In conclusion, N6 can be used as potential biocontrol resources to control cucumber Fusarium wilt caused by F. oxysporum f. sp. cucumerinum and promote the growth of seedlings for sustainable and efficient cucumber production. [ABSTRACT FROM AUTHOR]