Optimization of regeneration of red raspberry (Rubus idaeus L.) cultivars ‘Veten’ and ‘Ninni’ using different light qualities

Customizable light technology is becoming commercially available to producers, giving opportunity to increase control in plant production systems. Understanding of how specific light qualities affect different species and cultivars is necessary to develop light application protocols. In this study, the main objective was to optimize a micropropagation protocol for Rubus idaeus (red raspberry) comparing two cultivars, ‘Veten’ and ‘Ninni’. They were propagated through indirect organogenesis. After inoculation of leaf disks and petioles on callus induction media, cultures were subjected to blue, white, red, far red (40 μmol/s-1m-2 for 16 h) compared with darkness for 4-6 weeks. During the subsequent shoot proliferation, all cultures treatments subjected also to the other light treatments. Both cultivars responded positively, with variations, regarding explant types and light quality. Blue and red light can give equal or superior results to that of white light for shoot proliferation. Results also indicate high dependency of results on explant type, cultivar and lights quality, which implies that protocols should be customized to cultivars. ‘Ninni’ had the highest response to varying the explant type and light quality. Further research is needed to investigate applications to regulate morphogenesis and to increase efficiency of micropropagation of R. idaeus