用Czapek’s液体培养基培养的不同致病力类型的14个棉花黄萎病菌(Verticillium dahliae Kleb.)菌株进行毒素产生条件的研究。试验结果表明:各菌株的培养滤液中的毒素含量与培养天数、菌丝量有关。各菌株在pH3的Czapek’s培养液中都不生长。其滤液也不含毒素;在pH5～9的Czapek’s培养液中生长良好,产生毒素量明显增加。在相同pH的Czapek’s培养液中培养结果,致病力强的菌株产生毒素量高于致病力弱的菌株。 Fourteen strains of Verticillium dahliae Kleb. Of different virulence types cultured in Czapek’s broth were used to study toxin production conditions. The results showed that the toxin content in the culture filtrate of each strain was related to the days of cultivation and the amount of mycelium. Each strain did not grow in pH3 Czapek’s broth. The filtrate is also free of toxins; it grows well in Czapek’s broth at pH 5-9, with a significant increase in toxin production. As a result of culturing in Czapek’s broth of the same pH, the virulent strain produced a higher amount of toxin than the less virulent strain.