Culture medium, LEDs and bioreactor to improve in vitro propagation of red currant
Currently red currant (Ribes rubrum L.) is commonly propagated by cuttings because there is no suitable method for micropropagation available. This makes the introduction of new cultivars time-consuming. Development of micropropagation methods for red currants would improve the availability of good-quality planting material and also serve as a tool for the cryopreservation of old cultivars. Despite some considerable research efforts, the propagation of red currant by rooting of stem cuttings is still challenging. Our goal was to develop a micropropagation protocol for this species. We compared several different culture medium compositions including different sugar, growth regulator and macronutrient concentrations with in vitro cultures of four Finnish cultivars. The length of the propagation cycle was also examined. G basal medium with fructose and the hormones benzyl adenine (0.5 mg L-1) and indole-3-butyric acid (0.1 mg L-1) gave relatively good multiplication rates and shoot quality estimates for all cultivars. However, the height growth and rooting of the shoots in the experiments were not satisfactory within the solid medium in glass vessels grown under fluorescent lights. Therefore different light-emitting-diode (LED) lights and a Plant Form-based temporary immersion bioreactor were applied to improve height, quality and the acclimatization process of shoots. Combinations of white, red and blue wavelengths had positive impacts on shoot quality. The bioreactor treatment improved significantly shoot height and rooting of the plantlets. Medium requirements, however, were found to differ from solid cultures and further optimization of conditions and medium are needed for bioreactor-based shoot propagation. Nevertheless, a set of protocols which enable propagation, rooting and acclimatization of red currants are now available for application.
Hautsalo, J., Rantala, S., Rantanen, M. and Nukari, A. (2018). Culture medium, LEDs and bioreactor to improve in vitro propagation of red currant. Acta Hortic. 1224, 209-216
temporary immersion, bioreactor, hormones, light quality, micropropagation