Disease cycle of late blight of potato and tomato caused by phytophthora infestans Sporangium Sporangium Germination Sporangium Oospore Sporangiophore on infected seedling Karyogamy Oogoniun Sporongium porangiophor n infected Germ tub in spring】 on leaf Infected leaf Infected Sexuol reproduction extremely rore in nature Infected plant FIGURE 11-22 Disease cycle of late hlight of potato and tomato caused by Phrytophtora infeDisease cycle of late blight of potato and tomato caused by phytophthora infestans