Root induction on in vitro Simmondsia chinensis shoots was improved after 60 days cocultivation with Agrobacterium rhizogenes, with or without 490 mu M IBA simultaneously added. The three strains used (A4, 1601 and 9402) increased the rooting percentage to 80, 73.4 and 73.3%, respectively. IBA produced calli at the base of the stem in similar percentages than 9402 or 1601 strains, but calli was notably reduced when A4 strain or combined treatments (Agrobacterium and IBA) were used. Cefotaxime improved rooting percentage respect to the controls, but this response was significantly increased between 86 to 100% when A4 strain was used, solely or combined with IBA. Root number and root length were significantly enhanced at 523.6 mu M cefotaxime respect to uninfected plants. Combined bacteria-IBA-cefotaxime treatments significantly augmented all studied parameters. Negative opine detection did not let us confirm that the roots formed under the Agrobacterium influence were really transgenic.
