Optimizing factors influencing micropropagation of ‘Bluecrop’ and ‘Biloxi’ blueberries and evaluation of their morpho-physiological characteristics during ex vitro acclimatization

BACKGROUND: Blueberry production has generated great commercial expectations, therefore for its agricultural expansion it is necessary to overcome the challenges at the time of mass propagation. OBJECTIVE: Evaluate the effect of a set of factors influencing micropropagation, as well as the influence of substrates on the ex vitro morpho-physiological performance of blueberry seedlings. METHODS: A set of protocols were developed to optimize all stages of micropropagation (aseptic establishment, multiplication, rooting, and acclimatization) of blueberries. RESULTS: Explants immersed in 1.5% NaClO for 8 min and then in 0.1% HgCl2 for 2 min achieved 100% sterility and a viability rate of 86.67% for ‘Biloxi’ and 93.33% for ‘Bluecrop’. At the multiplication stage, the maximum number of shoots of ‘Biloxi’ (3.53) and ‘Bluecrop’ (2.27) were obtained on the medium supplemented with 0.2 and 10 mg L–1 silver nanoparticles (AgNPs), respectively. The percentage of in vitro rooting was significantly improved on media containing activated charcoal, with levels between 80% and 100% . In the acclimatization phase, plants grown in a substrate composed of peat and cocomix® (2:1 ratio) showed greater uniformity and better morpho-physiological behavior. CONCLUSIONS: The present results could be successfully used for large-scale commercial production of blueberries of the varieties ‘Biloxi’ and ‘Bluecrop’.