Rapid introduction of early season sweet cherry cultivars through in vitro micropropagation and virus elimination

In vitro propagation techniques were used for the rapid introduction of new imported sweet cherry (Prunus avium L.) cultivars, 17 H 580, 40 E 50 and 106 EB 325. Media for bud establishment, bud shoot proliferation, shoot elongation and rooting were developed for each of them. The cultivars differed in their response to different media compositions. Indexing on several plant indicators under quarantine conditions found the cultivars 40 E 50 and 106 EB 325 to be virus infected. In vitro thermotherapy in combination with shoot-tip culturing was successfully applied. Virus-free cultures were rooted, acclimated and grown under greenhouse and field conditions.