向日葵黄萎病病原鉴定

Identification of causal agent for sunflower Verticillium wilt

从黑龙江、内蒙古东部和西部、河北、陕西、宁夏、新疆向日葵黄萎病发生严重的地块采集有典型症状的200多个病株进行病原物分离,通过常规组织分离法分离到120个菌株。在PDA培养基上,其菌落表现黑色、白色及灰白色。显微镜下观察其营养菌丝透明、有分隔,呈轮状分枝;分生孢子卵圆或椭圆形、单细胞;大多产生黑色微菌核。提取DNA并进行ITS序列分析(ITS1/ITS4),证实该120个向日葵黄萎病菌株均为轮枝孢属大丽轮枝菌(Verticillium dahliae Kleb.)。

More than 200 diseased plants having shown typical Verticillium wilt symptoms were collected from Heilongjiang,Inner Mongolia Autonomous Region,Hebei,Shanxi,Shaanxi,Ningxia Hui Autonomous Region and the Xinjiang Uygur Autonomous Region.120 strains obtained by tissue isolation technics were identified.On PDA,the colonies showed black,white or gray white.The vegetative mycelium was hyaline and septate.Conidia were ovoid or ellipsoid and single-celled.They were borne on phialides,which were produced in a whorl around each conidiophore.Most of these isolates produced black microsclerotia.Genomic DNA was extracted and used as a template for amplification of the internal transcribed spacer（ITS） region of rDNA with primer pair ITS1/ITS4.All of the 120 strains were identified as Verticillium dahliae Kleb.