淡紫拟青霉次生代谢物质的抑菌效应

The inhibition effect of secondary metabolite of Paecilomyces lilacinus against Fusarium oxysporum

研究了淡紫拟青霉次生代谢物质不同浓度、不同培养时段、不同培养基培养对尖孢镰刀菌菌落生长与孢子萌发的抑制作用。结果表明：淡紫拟青霉次生代谢物质对尖孢镰刀菌的菌落生长与孢子萌发有显著的抑制作用；对菌丝生长的抑制率随浓度升高而升高，1％浓度处理，第7天的校正抑制率为42．78％，5％处理校正抑制率可达到80．56％；淡紫拟青霉的抑菌活性随培养时间的推延而上升，发酵后期（4～10天）抑菌活性较强，校正抑菌率均可达到70％以上。11天，菌液的活力又有所下降，校正抑菌率仅48．49％；不同培养基对淡紫拟青霉次生代谢物的抑菌活力有一定影响，察培克、PDA、盂加拉红的抑菌活力最高，对菌落的抑制率在72％左右，产孢抑制率达到90％以上。

An investigation was carried out to examine the effect of the secondary metabolite extracted from Paecilomyces lilacinus on Fusariurn oxysporum Schl. The results showed that the secondary metabolite at different concentrations, different culturing terms and cultured by different media would express different inhibiting results against the spore germination and colony growth of Fusarium oxysporum. Judged by appearances, the treated colony grew slowly and badly-distributed on the media. Studied on effect of different concentrations on the inhibition efficiency had been carried out, results showed that the inhibited rates increased along with the concentration increasing. When treated with concentration of 1%, the inhibition rate was 42.78% and treated by 5% secondary metabolite after 7d, the inhibition rate was 80.56%. The inhibition results of the antagonistic secondary metabolite cuhured at a constant term of 1 - 11 d had been investigated. Tests result showed that treated with antagonistic secondary metabolite cultured at a constant term of 4 - 10d, the relative inhibiting rates of all treatments were above 70% at 4% concentration after 7d. But the relative inhibiting rates gone down by 48.49% when treated with 11d secondary metabolite. Another study was conducted to compare the antagonistic efficacy of secondary metabolite cultured by different ＇media against Fusarium oxysporum. When treated with secondary metabolite cultured by Czapek, PDA and Martin-Johnson media, the highest inhibiting rate to colony and sporulation were over 72% and 90% respectively, meanwhile the data tested by LSD there were no significantly differences between the antagonistic result of Czapek culture and hymexazol （400 x ） treated after 7d. It seems that Paecilomyces lilacinus strain NH-PL-03 can be used as biological agent against Fusarium oxysporum.