Prunus species plantlets could be regenerated from root callus on a medium defined by Quirin and Lepoivre. The calli were formed on the roots of plantlets derived from meristem culture containing 6-benzylaminopurine and Gibberellic acid. Micropropagation of Rosa hybrida L. cultivars is also described on this medium. Quoirin & Lepoivre medium has several differences in comparison to Murashige & Skoog. The ammonium ion concentration is strongly reduced, the calcium ion concentration is -increased and the chlorine ions are almost eliminated. This formulation avoids vitrification problems.