In vitro high-frequency regeneration of half-highbush ‘Northland’ blueberry

Abstract

An efficient protocol is developed for adventitious shoot regeneration from nodal and leaf explants of the half-highbush blueberry cultivar ‘Northland’. In vitro-derived nodal segments are used to form adventitious shoots on pH 5.0 modified woody plant medium (WPM) containing 4 mg/L zeatin, 0.8% (w/v) agar and 2% (w/v) sucrose. This media is deemed suitable based on adventitious shoot multiplication rate and plantlet number and height, and it also achieves the best adventitious shoot induction from leaf explants. Shoots are rooted on half-strength modified WPM containing indole-3-butyric acid (IBA) or a-naphthaleneacetic acid (NAA) and 0 or 0.2% (w/v) activated charcoal, with 2 mg/L IBA and 0.2% (w/v) activated charcoal found best for easy root induction. Rooted plantlets are transferred to plug trays containing 1:1:1 peat:sand:vermiculite adjusted to pH 4.5 with ferrous sulphate, and readily acclimatized under greenhouse conditions.