Efficient micropropagation protocol for highbush blueberry (Vaccinium corymbosum L.) cv. 'Elliot'

Blueberries have a high nutritional value and strong antioxidant properties, qualities which account for their increasing request on the food and pharmaceutical markets. Cultivar 'Elliot' has a balanced content of active substances. It is also a late ripening cultivar suitable for long Transylvanian winters, which makes it a good candidate for large scale cultivation in this region. Because traditional propagation methods of highbush blueberry have several drawbacks, studies for creating an efficient micropropagation protocol were initiated. Dormant buds were used as initial explants for shoot regeneration while axillary and adventitious microshoots were further used for the proliferation stage. The influence of several plant growth regulators (2-iP, Zeatin, BAP) in relation with the explant positioning into media was investigated in order to ensure the highest proliferation rate. WPM supplemented with zeatin 2 mg l(-1) and 2-iP 5 mg l(-1) along with horizontal microshoot positioning gave the best proliferation rate, with an average of 17.9 shoots/explant. In vitro obtained leaves were tested for their regeneration capacity. The use of 2-iP 10 mg l(-1) produced up to 90% regeneration rate. The best variant consisted in abaxial leaf positioning which resulted in 50% direct regeneration rate and an average of 6.5 shoots/initial explant. The maximum proliferation rate was recorded for adaxial positioning (26 shoots/initial explant). Direct ex vitro acclimatization and rooting in hydroculture were also tested with very good results.