The effects of growth regulators, carbon sources and salt media were studied on in vitro shoot
proliferation from lateral bud explants obtained from 2- to 5-year-old plants of Rosa hybrida cv.
Baronesse. The final medium adopted included the salt formulation of Quoirin and Lepoivre [Acta
Hortic. 78 (1977) 437], 30 g l1 of sucrose, benzyladenine (3.0 mg l1) and naphthaleneacetic acid
(0.5 mg l1). Under these conditions, a multiplication rate of 30.3 plantlets per explant was
obtained after 180 days. This system was also effective for the multiplication of six out of the other
nine cultivars evaluated with a multiplication rate of 1.85–2.88 plantlets per explant after 60 days in
culture. # 2002 Elsevier Science B.V. All rights reserved.