Abstract

Initial acclimatization of in vitro-rooted plantlets of miniature rose (Rosa chinensis var. minima ‘Red Ace’) in high humidity and continuous light (most similar to the in vitro environment) increased plant growth (33% greater root area and 34% greater shoot area) relative to plants acclimatized under intermittent mist during early ex vitro growth stages, but later transfer to standard greenhouse conditions caused a temporary lag in continued growth. Direct transfer from in vitro culture conditions to a greenhouse mist bench inhibited growth during acclimatization, but permitted more rapid growth rate (28 and 30% more shoot and root area, respectively) during transition to the greenhouse growing environment. Direct transplant of in vitro rooted microcuttings to a growing medium containing soil resulted in high survival rate and circumvented the need for an interim potting medium, whereas transplant to Jiffy-9 pellets resulted in the highest plant losses.