A scale-up system for Lowbush Blueberry micropropagation using a bioreactor

In an attempt to improve the micropropagation protocol for lowbush blueberry (Vaccinium angustifolium Ait.), a protocol using a bioreactor system combined with a semisolid gelled medium has been developed. Cultures of cultivar Fundy and two wild clones ('NB1' and 'QB1')were established in vitro on a gelled modified cranberry basal medium (BM)containing 5? M zeatin or 10 ? M N6-[2-isopentenyl]adenine. Multiple shoots were obtained within 8 weeks by transferring zeatin-induced shoots from the gelled BM to a bioreactor containing liquid BM with 1 to 4? M zeatin. Genotypes differed significantly with respect to multiplication rate in liquid and gelled BM containing 1? M zeatin with 'NB1' producing 8.5 ± 1.1 and 2.9 ± 0.3 shoots per explant in liquid and gelled media, respectively, after one subculture followed by 'QB1' (7.1 ± 0.6 and 2.6 ± 0.4 shoots per explant, respectively)and 'Fundy' (5.8 ± 0.4 and 2.0 ± 0.2 shoots per explant, respectively). With subculture, there was an increase of shoot multiplication rate for all genotypes. Bioreactor- and gelled medium-proliferated shoots were treated with 39.4 mM indole-3-butyric acid powder, rooted in a 2 peat:1 perlite (v/v)medium, plantlets acclimatized, and eventually established in the greenhouse with 64 percent to 74 percent rooting of microshoots and 90 percent to 99 percent survival of rooted shoots. Results obtained suggested the possibility of large-scale multiplication of lowbush blueberry shoots in bioreactors.