Abstract: Agrobacteriurn tumefaciens-mediated transformation system was used to study the factors influencing transformation in cassava. Histochemical GUS assay showed that the transient expression rate was significantly improved by using the following transformation conditions: GV3101 as A.tumefaciens strains, infection time 30-45 min, co-culture time 3-4 d, engineering bacterium concentration (OD₆₀₀) 0.45 and application of 200 μmol·L^-1 AS. However, pre-culture showed negative influence on the transient expression rate. Eight transgenic cassava plants from 453 explants were obtained in this study and the integration of glgC336 transgene was confirmed by PCR and Southern blot analysis. The transformation frequency was 1.77%.

Key words: cassava(Manihot esculenta Crantz), agrobacterium-mediated, transformation