危害禾本科植物的霜霉病菌主要有霜霉科中指梗霉属(Sclerospora)和指疫霉属(Sclerophthora)。本文介绍的禾谷类作物霜霉病是指由指疫霉属中指疫霉[S.macrospora(Sacc.)Thirum et al.]引起的水稻、小麦、大麦和玉米等主要禾谷类作物霜霉病(又称黄化萎缩病)。这种病害在国内发生历史久远,分布亦广。由于这种病害是系统侵染的,病株多不结实,发病率就是损 Downy mildew-threatening Gramineae are mainly Sclerospora and Sclerophthora. The term “downy mildew” for cereal crops introduced in this article refers to the major millet mildew disease of rice, wheat, barley and maize, caused by Phytophthora infestans [S. macrospora (Sacc.) Thirum et al. Also known as yellow atrophy disease). This disease has a long history in the country and its distribution is also wide. As the disease is systemic infection, the disease is not more than strong, the incidence is loss