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70年代以来,大白菜黑腐病在北京、山西、山东等地普遍发生且较严重.1987年8月下旬,我们首先在昌吉市滨湖乡下泉子一队的大白菜田中发现本病,后对昌吉市其他白菜田进行多点调查,均见到本病发生,其中六工乡东五工二队(青杂中丰品种)9月29日发病率为26%,病情指数12.0%,10月22日发病率上升至87.0%.此年本地杂交种大白菜发病率达100%.为此,我们采集病叶、病根进行病原菌分离、回接、鉴定,结果如下.一、症状大白菜黑腐病菌主要侵害植株的维管束部分.据观察,幼苗期发病的植株,根部变细,呈黄褐色,有时呈腐烂状,地上部萎蔫,枯倒;成株期发病,外层叶叶缘常有明显的“V”形黄褐色病斑或不规则形黄色病斑,叶脉由黄逐渐变黑,湿度大时呈湿腐
Since the 1970s, the black rot disease of cabbage has been common and serious in Beijing, Shanxi, Shandong, etc. In late August 1987, we first found this disease in a Chinese cabbage field of a team of Xiaquanzi in Binhu Township, Changji City, Changji City, other cabbage fields for more investigations, are seen of the disease, of which Liu workers Township East Fifth Five teams (Green Zhaofeng varieties) on September 29 incidence of 26%, disease index 12.0%, October On the 22th the incidence rose to 87.0% .In this year the local hybrid cabbage incidence of 100% .To this end, we collected diseased leaves, diseased roots for pathogenic bacteria separation, back, identification, the results are as follows. Pathogen mainly affects the vascular bundle part of the plant.It is observed that the seedling plants in the seedling stage, the roots become thin, yellowish brown, sometimes rotten, the upper part wilting, fall down; adult disease, the outer leaf margin often Obvious “V” -shaped brown spots or irregular yellow lesions, veins gradually darken from yellow, wet when wet