甜菜丛根病是1978年在我国内蒙地区发现的一种新病害。1979年笔者从该病病株根表皮细胞中发现甜菜多粘菌(polymyxa betae)的寄生,并与甜菜毛根坏死病(后定名为丛根病)的发生有密切关系。随后用三年时间(1980～1982年)在研究“甜菜丛根病发生及防治”的同时,对该菌的形态及其生活史进行一些观察,本文将阐述对polymy-xa betae的观察结果,仅供参考。 Beet root disease is a new disease discovered in Inner Mongolia in 1978. In 1979, the author found the parasitism of polymyxa betae from root epidermal cells of the diseased plant and was closely related to the occurrence of beet root necrosis (later named rhizomania). In the next three years (1980-1982), we studied the occurrence and prevention of root disease of sugar beet, and observed the morphology and life history of the fungus. In this paper, the results of the observation of polymy-xa betae, for reference only.