暗黑链霉菌PY-1活性产物分析及其对葡萄霜霉病田间防效评价

为探究暗黑链霉菌Streptomyces atratus PY-1对葡萄霜霉病菌Plasomopara viticola的抑制作用,通过扫描电镜观察PY-1发酵滤液对葡萄霜霉病菌孢子囊的影响,检测PY-1的活性物质种类,并测定其对葡萄霜霉病的田间防效。结果表明,PY-1发酵滤液能够导致葡萄霜霉病菌孢子囊和孢子囊梗出现褶皱、破裂和畸形,进而使其丧失侵染功能。PY-1菌株代谢产物中包含几丁质酶、蛋白酶、嗜铁素、1-氨基环丙烷-1-羧酸脱氨酶、氰化氢、吲哚乙酸,不含纤维素酶。PY-1菌株对葡萄霜霉病具有较好的田间防效,发酵原液对葡萄霜霉病的田间中期防效可达到89.17%以上,末期防效达86.28%以上,比52.5%噁唑菌酮·霜脲氰2 000倍液的防效略低,但显著高于58%甲霜·锰锌1 000倍液的防效;PY-1菌株发酵液稀释700倍后对葡萄霜霉病的末期防效与甲霜锰锌1 000倍液防效相当。表明PY-1菌株具有研制防治葡萄霜霉病生防制剂的潜力。

Study on bioactive metabolite of Streptomyces atratus PY-1 and the field control efficiency against grapevine downy mildew

To explore the inhibitory effect of Streptomyces atratus PY-1 against Plasomopara viticola, the effects of PY-1 strain by filtered broth on sporangium of P. viticola was tested, the bioactive substances were detected using specific medium and the biocontrol effect was evaluated on field experiments. The results showed that sporangium and sporangiophore of pathogen were wrinkled, wizened and fracture after treated with extracts of PY-1 filtered broth. The metabolite of PY-1 strain included chitinase, protease, siderophore, 1-aminocyclopropane-1-caboxylate deaminase, hydrogen cyanide, indole-3-acetic acid, but excluded cellulase. The original fermentation solution of PY-1 had great control effect on grape downy mildew. The metaphase control effect on grape downy mildew was up to 89.17%, and the control effect at the end stage could be above 86.28%. It was slightly lower than the equation-pro WG of 52.5% with 2 000-fold, but significantly higher than 58% metalaxyl-mancozeb with 1 000-fold. When the broth of PY-1 was diluted for 700-fold, the control effect was equal to 58% metalaxyl-mancozeb diluted by 1 000-fold. The results indicated that strain PY-1 could potentially be a biocontrol agents to be developed for controlling grapevine downy mildew.