In vitro proliferation and ex vitro rooting of microshoots of commercially important rabbiteye blueberry (Vaccinium ashei Reade) using spectral lights

Abstract

Efficient protocols for in vitro shoot growth and ex vitro root formation from in vitro-derived shoots under light-emitting diodes (LEDs) with simple ventilation were developed for rabbiteye blueberry cv. ‘Titan’. Red LEDs promoted shoot elongation while blue LEDs induced short shoots with enhanced accumulation of leaf chlorophyll contents. A combined treatment of 80% red with 20% blue LEDs was found the most suitable for plant growth, and more effective than 50% red mixed with 50% blue LEDs or fluorescent lamps as the control treatment. The use of ventilated vessels with ambient CO2 enrichment from a growth chamber resulted in healthy plants having greatly improved shoot length, leaf expansion, leaf chlorophyll contents and dry weight of both shoots and roots. In vitro-cultured shoots could be directly rooted at 100% under non-sterile conditions using a perlite-peat mixture with careful controls of high humidity. These results suggest that LEDs, particularly when coupled with ventilated vessels, should be used as a primary light source for replacing conventional fluorescent tubes in large-scale production of rabbiteye blueberries.