Micropropagation of floribunda, ground cover and miniature roses

Abstract

Cultures were initiated from meristems (0.5 mm) of the rose cultivar Queen Elizabeth (floribunda) and from both shoot-tips and nodal explants (3–5 mm) of cultivars Sunburst Red, Toy Clown (miniatures) and Fiona (ground cover). Average proliferations of 5.0, 3.1, 1.3 and 2.5 shoots were obtained per culture cycle respectively on Murashige & Skoog (MS) medium with BA (1.0 mg l-1), NAA (0.1 mg l-1) and GA3 (0.1 mg l-1). With cv. Fiona, the proliferation rate was more than doubled by removal of the shoot apex. The rate of proliferation of cv. Queen Elizabeth was significantly increased by using long shoots (>2 cm in length) and by re-culturing shoots to fresh medium every 3 weeks. In vitro rooting percentage with cv. Queen Elizabeth was enhanced by using long shoots (>2 cm) and by dilution of MS medium to 1/4 strength. Transfer of shoots for direct rooting in compost was significantly improved by pre-culturing shoots for two weeks in vitro in media containing IAA, and by the use of sorbarods.