Microclonal propagation of Vaccinium sp. and Rubus sp. and detection of genetic variability in culture in vitro

Abstract

Five high-bush blueberry, two lingonberry, and six raspberry cultivars were evaluated in terms of their regeneration capacity when propagated in vitro by axillary and adventitious organogenesis. In the high-bush blueberry and the lingonberry, shoots were regenerated from isolated meristems and dormant buds and cultivated on modified Anderson's rhododendron (AN) medium. Shoot formation was induced on medium containing 0.5 mg 1 -1 zeatin. In the high-bush blueberry, the cultivar with the highest shoot proliferation intensity was 'Brigitta', with 14.2 shoots per primary explant. The cultivars with the highest adventitious shoot multiplication were 'Brigitta', with 39.1 shoots/explant, and 'Berkeley', with 18.0 shoots/explant. In the lingonberry, the cultivar with the highest shoot proliferation intensity was 'Red Pearl', with 5.2 shoots per primary explant. The cultivar with the highest adventitious shoot multiplication was 'Red Pearl' with about 44 shoots/explant. In the raspberry, shoots were regenerated from isolated meristems and dormant buds and cultivated on modified MS medium containing 1.0 mg I -1 BAP and 0.1 mg I -1 IBA. The cultivar with the best meristem formation and shoot proliferation was 'Bulharsky Rubin', with 56.6% of the explants producing shoots. Adventitious shoot regeneration was also highest in 'Bulharsky Rubin', with 25.75 of leaf explants producing adventitious shoots on MS medium containing 0.5 mg 1 -1 TDZ and 0.2 mg 1 -1 2,4-D. RAPD proved to be a simple and efficient technique for identifying high-bush blueberry and lingonberry clones, which could easily be distinguished by their characteristic polymorphic banding patterns. However, there were no differences in the DNA profiles of the mother cultivars and any of the clones derived from them. Therefore, either no somaclonal variation occurred during the micropropagation process, or more sensitive techniques are needed to detect it. Flow-cytometry did not detect any changes in ploidy level, which confirms that no relative changes in DNA content took place during the micro-propagation process.