SUSCEPTIBILITY OF BRAZILIAN SOYBEAN CULTIVARS TO AGROBACTERIUM-TUMEFACIENS

Transformation of soybean (Glycine max (L.)Merr.) via Agrobacterium is affected by the susceptibility of genotypes to specific Agrobacterium strains. Four Brazilian soybean cultivars were screened with A. tumef aciens strains A281=pZA3, A208 and C58. The tumor frequency and size v aried significantly among cultivars and strains. The relative frequenc y of tumor formation was greatest for strains A208 and C58 on all soyb ean cultivars tested. The cultivar BRAGG was most susceptible. Tumors showed hormone-independent growth. Tumor segments were opine positive. Tumors induced by A281=pZA3 also expressed the reporter GUS gene. The results indicated that some of the Brazilian soybean cultivars, e.g. BRAGG, can be used in Agrobacterium mediated gene transfer experiments .