平菇锈斑病发病症状识别及病原菌的形态特征鉴定

Identification of Pathogenesis and Pathogen Characterization Caused Rusty Spot Disease for Pleurotus ostreatus

为了准确识别平菇锈斑病的发病症状及明确病原菌的分类地位,笔者以初步鉴定为托拉斯假单胞杆菌的平菇锈斑病病原菌为材料,通过形态学特征、培养性状等方法对其进行进一步病原菌鉴定;采取自然发病和接种发病相结合的方式,观察病害前中后期的症状。结果表明:平菇锈斑病病原菌为革兰氏阴性,极生鞭毛1根或数根,在KB培养基上菌落圆形、乳白色,边缘整齐,微凸起,产生黄绿色荧光,进一步验证了该病原菌种属分类地位为托拉斯假单胞杆菌(Pseudomonastolaasii)。该病原菌在发病初期时子实体表面出现呈淡黄色或铁锈色针尖状大小病斑,发病重的地方病斑大,常以圆形、椭圆形或梭形出现,或菌盖表面呈现一片淡黄色,病斑周围有锈黄色晕圈;发病中期病斑凹陷,色泽也不断加深,呈现黄棕色或黄褐色;发病后期,菌褶扭曲,菌盖也会因病斑的逐渐凹陷而起皱开裂。子实体颜色变深,浅色菇变成黄色菇,深色菇转为黄褐色或酱色菇。

In order to accurately identify the symptoms and the classification status of pathogenic bacteria Caused Rusty Spot Disease for Pleurotus ostreatus,In this paper, the author use the pathogen which infected the Pleurotus ostreatus as the material and the pathogen was indentified as Pseudomonastolaasii preliminarily, and the morphological characteristics and culture traits were used to identify the pathogens; To observe the symptoms of the early middle and late stage of the disease by combining the natural pathogenesis and the symptoms of inoculation.The results showed that the pathogen coused Rusty spot disease for the Pleurotus ostreatus was gram-negative and the flagellum was one or several . The colonies were round, milky and white on the KB culture medium, and the edges were neat and slightly raised to produce kelly fluorescence, which further confirmed that the genus Phytophthora species is Pseudomonastolaasii.the pathogen＇s sporocarp appeared pale yellow or rusty needle-shaped size of the lesion at the beginning of the disease. The incidence of heavy spot lesions, often round, oval or fusiform appearance, or the pileus surface showing a pale yellow, around the lesion rust yellow halo; the incidence of disease in the middle of the depression, the color is also deepening, showing Yellow brown or yellowish brown ; late onset, gill distortion, the pileus will be due to the gradual depression of the lesion and wrin- kle Cracked. The color of Sporocarp becomes dark, light-colored mushrooms into yellow mushrooms,dark mushrooms into yellow or dark reddish brown mushrooms.