Effect of concentration, method of auxin application and cultivation conditions on in vitro rooting of bog blueberry (Vaccinium uliginosum L.)

BACKGROUND: Bog blueberry, Vaccinium uliginosum is one of the newer fruit crops. Choosing the most appropriate methods for mass vegetative propagation of V. uliginosum cultivars, including in vitro propagation, is crucial. OBJECTIVE: We investigated the effect of growth regulators and light on in vitro rhizogenesis of V. uliginosum to determine the optimal method of propagation. METHODS: The following cultivation techniques were tested on microshoots of bog blueberry varieties 'Golubaya rossyp', 'Nektarnaya', 'Shegarskaya' and 'Iksinskaya': 1) 1/2 Anderson (A) medium supplemented with 3 and 10 mu Mindole-3-butyric acid (IBA) or indole-3-acetic acid (IAA) and 2) 24-h aqueous treatments of microshoots with 148 mu M IBA or 171 mu M IAA and further cultivation in 1/2 A medium. In addition, we tested precultivation in darkness for 3 d versus a 16/8-h photoperiod. RESULTS: 100% rooting was observed in 'Golubaya rossyp' in all treatments of the experiments and with 'Nektarnaya' on the growth-regulator-free 1/2 A medium and after treating the microshoots with 171 mu M IAA solution. Precultivation in darkness produced a positive effect on rooting in 'Shegarskaya' and 'Iksinskaya.' CONCLUSIONS: Response to in vitro rooting techniques varied between cultivars of V. uliginosum. Treatment of microshoots with auxin solutions improved in vitro rooting.