Effects of antibiotics on plantlet regeneration via organogenesis in Populus euphratica

Four antibiotics, kanamycin, geneticin, carbenicillin and cefotaxime, were evaluated for their effect on the regeneration of adventitious buds, shoot differentiation, rooting from regenerated shoots of Populus euphratica as well as on their control of Agrobacterium-mediated transformations. Results showed that the optimum concentration ranges of kanamycin and geneticin were 15-20 and 10-15 mg·L^-1 at the stage of transgenic plantlet selection. The inhibitory effects of cefotaxime and carbenicillin varied among different genotypes of Agrobacterium. The inhibition of cefotaxime on Agrobacterium C58 was stronger than that of carbenicillin. The optimum concentration of cefotaxime was 100 mg·L^-1. Cefotaxime and carbenicillin had similar effects on Agrobacterium LBA4404 and their optimum concentrations were both 150 mg·L^-1.