烟草青枯病在长江以南烟区普遍发生,有些年份损失达60％以上。它是典型的维管束病,根、茎、叶都可受害,典型症状是枯萎。染病植株萎垂的叶片初期仍为青色,故名青枯病。烟株发病先是茎叶的导管变黑,随后病菌侵入皮层及髓部,外表出现黑色条斑。发病初期一二片 Tobacco bacterial wilt occurs generally in the tobacco area south of the Yangtze River, losing some 60% in some years. It is a typical vascular bundle disease, roots, stems, leaves can be affected, the typical symptoms are withered. Vertically frying leaves of infected plants are still early blue, hence the name of bacterial wilt. The onset of tobacco plant stems and leaves of the catheter darkening, then the bacteria invade the cortex and pith, the appearance of black streaks. One or two early onset