水稻纹枯病菌拮抗菌株F_2的抗菌活性

Antimicrobial Activity of An Antagonistic Strain F_2 Against Thanatephorus cucumeris

为探明拮抗菌株F2对水稻纹枯病菌的抗菌活性，采用菌饼法，研究了水稻纹枯病菌拮抗菌株F2的抗菌活性。结果表明：F2菌株发酵滤液中抗菌物质在5-7d 内产生较快，7d 时发酵滤液对水稻纹枯病菌抑菌率达62．5％；随着 F2菌株发酵滤液浓度的增加，其对水稻纹枯病菌的抑菌率呈上升趋势，当发酵滤液浓度为30％时，其对水稻纹枯病菌的抑菌率为74．27％，与0．75％的百菌清（76．47％）相当；PD 培养液发酵培养 F2菌株，其发酵滤液对水稻纹枯病菌的抑菌率最高，其余依次为牛肉膏蛋白胨培养液、LB 培养液、基础培养液和豆芽汁培养液；发酵滤液中抗菌物质对不同酸碱度、紫外线和储存时间的稳定性强，且热稳定性较好。

Antifungal activity of antagonistic strain F2 on T .cucumeris was studied by using fungus plugs method. The results showed that the rapid production period of antifungal substances in F2 fermentation filtrate were 5-7 d,and the 7 d reached the maximum inhibition rate of fermentation filtrate, 62.5% ,which positively correlated with concentration of the fermentation filtrate.The antifungal rate of 30% fermentation filtrate was 74.27%,which was similar to the effect in the 0.75% Chlorothalonil （76. 47%）.Anti T.cucumeris rate of F2 fermentation filtrate reached the peak when the filtrate was derived from PD broth,followed by beef extract peptone,LB,basis and bean sprouts juice broth.Antifungal substances in fermentation filtrate had good stability to pH,UV,storage time and temperature.