Somatic embryo formation from the calli was inhibited to various extents by all four
selective agents and was completely inhibited by 75 mg l1 of G418, 50 mg l1 or more of
hygromycin, or 3 mg l1 or more of bialaphos. On the other hand, both cefotaxime and
carbenicillin significantly promoted embryo formation at all concentrations tested.