胶孢镰刀菌产生串珠镰刀菌素的不稳定性

从陕北克山病病区分离到的两株串珠镰刀菌素产生菌株——胶孢镰刀菌(Fusarium subglutinans Wollenw.et Reinking)陕-6号和2-17号进行单孢分离,分别得到23和19个单孢分离株。这些单孢菌株可分为两种培养型:一种形态上与原始菌株相似,产生串珠镰刀菌素,产色素,具有大、小分生孢子,转管八次产毒量有下降;另一种则不产串珠镰刀菌素和孢子,无色素,后者在二株菌的单孢分离菌中所占比例分别为60.9％和15.8％。由此可见,胶孢镰刀菌产毒稳定性受异核体和该菌单核变异性共同影响。

THE UNSTABILITY OF MONILIFORMIN PRODUCTION BY FUSARIUM SUBGLUTINANS

Twenty three and nineteen single spores were obtained from strains Shaan-6 and 2-17 of Fusarium subglutinans respectively, both strains were isolated from Keshan disease region in Shaanxi Province. There were two types in the single spore isolates: one type produced moniliformin, pigment, macroconidia and micro-conidia, the yield of the toxin declined after the eighth transfer; the other type did not produce spores, pigment and moniliformin accounting for 60.9% and 15.8% in the single spore isolates of strains Shaan-6 and 2-17 respectively. It can be concluded that the moniliformin producing stability is influenced by both heterokar-yon and monokaryon variability.