INFLUENCE DES CONCENTRATIONS HORMONALES, DU MILIEU DE CULTURE ET D’UN ANTI-OXYDANT SUR LE TEMPS DE DOUBLAGE DES TIGES DE FRAMBOISIERS ’MADAWASKA’ CULTIVES IN VITRO
Our results show that the shoot doubling time is a useful and accurate parameter to characterize the effect of media on the multiplication rate of tissue-cultured raspberry (Rubus idaeus L. ’Madawaska’). We have determined that 1 mg L−1 of BA (benzyladenine) and 0–0.05 mg L−1 IB A (indole butyric acid) resulted in the highest rates of proliferation, with shoot doubling times of 19 and 18 d for MS (Murashige and Skoog) and Anderson medium, respectively. A reduction of 10 d in the shoot doubling time was obtained with the addition of ascorbic acid (50 mg L−1) to both MS and Anderson media. However, this treatment did not reduce yellowing of cultures since the chlorophyll content was not significantly different in presence or absence of ascorbic acid. Generally, the MS medium was superior to Anderson medium.Key words: Raspberry, doubling time, multiplication in vitro, ascorbic acid, Rubus idaeus L.