The effects of culture conditions on production of Phytophthora infestans crude toxin

The effects of pathogen Phytophthora infestans culture conditions,such as culture medium, light .temperature ,pH value and shaking,on crude toxin production were studied using tomato seed germination as the biologic test of toxicity of crude toxin. The results showed that the favorable culture conditions were rye liquid medium,pH value 6. 0-7. 0,culture temperature 20-22 C with successive darkening and shaking during culture. The production of crude toxin reached the highest level on the 16th day of culture.