根癌病俗称根瘤病、根肿病,在苗圃幼苗中发生较为普遍,病原为根癌土壤杆菌,可侵染苹果、梨、桃、杏等。 该病主要发生在植株根颈部。初期病部形成白色大小不等的瘤状物,内部组织松软,外表粗糙不平。随根系生长,瘤体不断长大,表面由灰白色渐变为褐色至暗 Root cancer commonly known as root nodule disease, clubroot disease occurs more commonly in nursery seedlings, the pathogen for Agrobacterium tumefaciens, can infect apple, pear, peach, apricot and so on. The disease occurs mainly in the root of the plant neck. The initial disease formed white nodules of varying sizes, the internal organization of soft, rough appearance. With root growth, tumor growing up, the surface gradient from gray to brown to dark