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为了明确拮抗性放线菌Ⅲ-61和A-21在植物病害生物防治中的实用价值,并为其后续的生防制剂的研发提供科学依据,对其在蔬菜枯萎病和灰霉病上的抗病活性进行了研究。其活菌体的抑菌活性检测采用平板对峙法;菌体代谢物的活性测定利用摇瓶发酵后经微孔滤膜过滤制备无菌发酵液,然后用滤纸片扩散法测定抑菌圈,用生长速率法测定对菌落扩展的抑制,用稀释药液凹玻片静置培养法测定对孢子萌发的抑制;温室防病试验采用盆栽接种法。结果显示,两菌株的平板菌落对黄瓜枯萎病菌和番茄灰霉病菌的抑菌带宽达17.5~20.9 mm;27℃,120 r/min摇瓶培养6 d的发酵液抑菌效果最好,其稀释倍数≤5的无菌滤液处理后经120 h对病原菌菌丝生长的抑制率仍达76.5%~100%,对分生孢子萌发的抑制率为100%;100倍稀释液对孢子萌发后的芽管具有致畸作用,使其顶端膨大或呈粗栉齿状而不再继续伸长;平板对峙培养中受抑病原菌菌落边缘的菌丝细胞壁崩解,原生质体外泄,表现出溶菌现象;其4倍稀释液对黄瓜枯萎病的温室盆栽防效分别为65.15%和60.61%,对番茄和辣椒灰霉病的防效为62.49%~89.76%。此研究结果表明这2个菌株具有很好的开发应用前景。
In order to clarify the practical value of antagonistic actinomycetes Ⅲ-61 and A-21 in the biological control of plant diseases and to provide a scientific basis for their subsequent development of biocontrol agents, Anti-disease activity was studied. The antibacterial activity of the live bacterial body was measured by the plate confrontation method; the activity of the bacterial metabolites was determined by using a microfiltration membrane to prepare a sterile fermentation broth after being fermented in a shake flask, and then the inhibition zone was determined by a filter paper diffusion method Growth inhibition was used to measure the inhibition of colonization. The inhibitory effect on spore germination was determined by the stationary culture of dilute chemical solution of concave glass slide. The greenhouse inoculation method was potted inoculation method. The results showed that the antibacterial bands of the two bacterial strains were 17.5-20.9 mm against Fusarium oxysporum and Botrytis cinerea, and the best antibacterial activity was obtained at 27 ° C for 120 days at 120 r / min. The inhibition rate of the mycelial growth of pathogens was still up to 76.5% -100% and the inhibition rate on the conidiospore germination was 100% after 120 h treatment with sterile filtrate with multiples of ≤5. The 100-fold dilution of spores Tube teratogenic effect, so that the top of the swollen or thick combs rather no longer continue to grow; plate confrontation culture inhibition pathogen colonies at the edge of mycelial cell wall disintegration, protoplast leakage, showing the phenomenon of 4; its 4 The control effect of double dilution on greenhouse cucumber blight was 65.15% and 60.61% respectively, and the control effect on tomato and pepper gray mold was 62.49% ~ 89.76%. The results of this study show that these two strains have a good prospect of development and application.