贵州独山县水稻霜霉病的发生及鉴定方法

Occurrence and Identification of Rice Downy Mildew in Dushan,Guizhou

对贵州独山县感病水稻病害症状观察表明，受害水稻植株矮化，比健壮植株矮1／3～1／2左右，受害株心叶褪绿呈淡黄色或黄白色且严重扭曲畸形。采用组织整体透明法和荧光染色法对感病植株观察鉴定，观察到病组织内有大量孢子囊，根据病害症状特征，病原菌孢子囊特征，可确定此水稻病害为霜霉病。气候条件与育秧方式是水稻霜霉病发病与传播的关键因素。在防治过程中应该把农业防治放在首位，同时辅以必要的药剂防治。

Symptoms of infected rice in Dushan, Guizhou were examined, it showed that infected plants were stunt, 1/3 - 1/2 shorter than healthy plants, and spear leaves chlorosis to pale yellow or yellow-white, twisted and deformity. Tissue transparency and fluorescent stain methods were adopted to indentify the infected plants, big amount of sporangium were observed in infected tissues. And it was identified as downy mildew （Sclerophthora macrospora ） according to the character of symptom and pathogen sporangium. Climatic and seedling raising patterns are the key factors for the occurrence and widespread of rice downy mildew. Agricultural control should be taken as priority, and chemical control could be combined to control the downy mildew.