[The spreading of Agrobacterium strains in soft-agar (author's transl)].

In a diluted synthetic medium solidified by 0.17% agar populations of Agrobacterium spread with a velocity of 0 to 20 mm/24 hours. This spreading is a consequence of chemotactic movement and cell division. Different bacterial strains spread with a characteristic velocity each. Loss of the TI-plasmid leaves the spreading behaviour unimpaired. It is changed after the introduction of virulence by Kerr transfer or after prolonged culture in D-amino acids.