解淀粉芽孢杆菌gfj-4发酵上清液及其混剂对番茄早疫病菌抑制活性研究

为探究解淀粉芽孢杆菌(Bacillus amyloliquefaciens)gfj-4次级代谢产物及其化学杀菌剂复配剂对番茄早疫病菌(Alternaria solani)抑制活性。文章采用菌丝生长速率法测定接种量、发酵培养时间对抑菌物质的影响及发酵上清液、脂肽粗提物、发酵上清液与化学杀菌剂混配剂的病菌抑制活性。结果表明,种子液最适接种量为0.125%(V/V),最适发酵时间为96 h。生防菌发酵上清液和脂肽粗提物对番茄早疫病菌EC50分别为3.774和0.943μL·m L-1。番茄早疫病菌对咪鲜胺、苯醚甲环唑和丙环唑敏感性较高,其中咪鲜胺对病菌EC50达0.095μg·m L-1。发酵上清液和吡唑醚菌酯混配主要表现为相加和增效作用,其中以8.2比例混配毒性比最高为1.26。研究结果可为番茄早疫病防治措施更新和研制新配方农药提供理论依据。

Study on inhibitory of Bacillus amyloliquefaciens gfj-4 fermentation supernatant and its mixture with chemical fungicides against Alternaria solani

In order to investigate the inhibitory activity of the secondary metabolites of Bacillus amyloliquefaciens gfj-4 and its mixture with chemical fungicides against A. solani, the effects of inoculation amount and fermentation time on the production of antifungal substances, and the antifungal activity of the fermentation supernatant, lipopeptide crude extract and the mixture of fermentation supernatant and fungicides were determined by mycelial growth rate method. The results showed that the optimum inoculation amount of seed liquid was 0.125% (V/V), and the optimum fermentation time was 96 h. The EC50 of the fermentation supernatant and lipopeptide crude extract were 3.774 and 0.943 μL·mL-1for A. solani, respectively. The pathogen had a high sensitivity to ergosterol biosynthesis inhibitors prochloraz, difenoconazole and propiconazole. Among them, prochloraz had the highest inhibitory activity against A. solani with EC50of 0.095 μg· mL- 1. The mixture between Bacillus amyloliquefaciens gfj-4 fermentation supernatant and pyraclostrobin presented the synergistic or additive effects, which the ratio of 8∶2 reached the highest toxicity ratio of 1.26. This study can provide a theoretical basis for updating control measures of tomato early blight and development of new formula pesticides.