betae (Key-worth Howell and Bowson) Collins and Jones, two root diseases were sugarbeet crown gall Agrobacterium tumefaciens (Smith and Townsead) Conn and sugarbeet soft root rot Erwinia carotovora subsp carototora (Jones) Bergey et al.

• betae(Keyworth Howell andBowson)Collins and Jones.；两种根病为甜菜根癌病Agrobacterium tume-faciens(Smith and Townsend)Conn