Oospores of Phytophthora infestans

This paper represents a review on oospores of P. infestans, their formation in vitro, under natural conditions after artificial mating and in the field P. infestans populations. The aspects of oospore morphology, ecology, monitoring, and origin in potato and tomato are discussed. It is concluded that P. infestans from tomato seems to be a potentially dangerous source for late blight of potato under the field conditions of Moscow region. The data on oospores should be used for optimization of forecasting of late blight, as well as protection, and cultivar application strategies.