芽孢杆菌LP-3抗菌物质的初分离及抑菌活性测定

内生芽孢杆菌LP-3对多种植物真菌具有抑制作用,为分析其分泌的抗菌物质的抑菌活性,分别采用5种有机溶剂对抑菌物质进行萃取,比较了抗菌粗提物与两种杀菌剂对梨黑斑病菌的抑菌效果,测定了粗提物对9种植物病原菌的毒力,结果表明,甲醇萃取物对梨黑斑病菌的抑制效果最佳,抑菌率可达68.4%,对病菌菌丝及孢子的EC50分别为1.18mg.L-1和3.61mg.L-1,介于腐霉利和异菌脲之间,显示出良好的抑菌活性,而且该物质抗菌谱广,对9种植物病原菌的EC50在1.18mg.L-1～67.93mg.L-1之间。

Isolation of the Antifungal Substances from Endophytic Bacillus LP-3 and Determination on Its Antifungal Activity

Endophytic Bacillus strain LP-3 could against many kinds of plant pathogens.To study the antifungal activity of the antifungal substance produced by the strain LP-3,the active constituents were extracted with five organic solvents.The antifungal activity of extracts was compared with other two fungicides to A.alternata,the toxicities of the extracts were determined on nine kinds of plant pathogenic fungi.The results showed that the methanol extracts showed a perfect inhibition against A.alternata with 68.4%,and had stronger antifungal activity against filament growth and conidia germination of A.alternata with EC50 of 1.18 mg·L-1 and 3.61 mg·L-1,respectively,which ranged from procymidone to iprodione.The extracts also had a broad antifungal spectrum,which could inhibited the filaments of nine kinds of pathogenic fungi with the EC50 of 1.18~67.93 mg·L-1.