ATTACHMENT OF AGROBACTERIA TO GRAPE CELLS

The presence of the Ti plasmid favorably influences the attachment of agrobacteria to grape callus cells, especially during the early stages of a 2-h incubation. Agrobacterium strains attached to a similar exte nt to both the crown gall-resistant cultivar (Catawba), Vitis labrusca na, and the crown gall-susceptible cultivar (Chancellor), Vitis sp. At tachment of the virulent strain to grape callus cells is blocked by th e avirulent strain HLB-2 in both the tissue culture cell suspension an d the seedling root systems.