SUSCEPTIBILITY OF SOME BRAZILIAN SOYBEAN GENOTYPES TO 3 STRAINS OF AGROBACTERIUM-TUMEFACIENS

Twenty-six soybean (Glycine max (L.) Merrill) genotypes were screened for susceptibility to three strains of Agrobacterium tumefaciens. The genotype Peking, the most susceptible cultivar known, was used as the control. The strains of A. tumefaciens used included: C-58 (nopaline), Bo-542 (agropine), and Ach-5 (octopine). The cultivars were evaluated in the greenhouse in a randomized complete block design, with two rep lications. The genotypes IAC-5, IAC-14, and Peking were the most susce ptible to strain C-58; IAC-4 IAC-10, and Peking were susceptible to st rain Ach-5; and IAC-5 IAC-7 and IAC-12 were the most susceptible to st rain Bo-542, with susceptibility greater than for Peking. Strong and s ignificant interaction between genotypes and strains of A. tumefaciens was also observed.