Abstract: Crown gall strains caused by Agrobacterium tumefaciens S-1 702, C-58 have been established from sunflower hypocotyls, tobacco stems and stem pithes,carrot roots and potato tubers. The growth of galls and the appearance of teratomas were investgated. Some crown galls strains changed properties many months after induction. A sunflower crown gall strain changed its shape and growth speed seven months after induction. The teratoma of potato tuber aused by A. tumefaciens S- 1 appeared in the early stage of crown gall induction, but the teratomas arisen from two tobacco unorganized crown gall strains caused by A. tumefaciens 702 about 155 days after induction. Two tobacco crown gall strains caused by different A. tumefaciens strains have different response to phytohomone. Several teratoma strains with different differentiation have been obtained. The reversion of crown galls was investigated by means of induction with phytohormone. Plantlets have been induced from two carrot crown gall strains and two tobacco crown gall strains. All crowngall strains and teratomas produce nopaline. Nopaline was detected from the tobacco plantlet inducted from teratoma.

Key words: induction, culture, plant, crown, calls