IN VITRO PROPAGATION OF MUSSAENDA (Mussaenda erythrophylla cv. Rosea)

Abstract

This research aimed to develop a protocol for the micropropagation of Mussaenda erytrophylla cv. Rosea. Calcium hypochlorite or sodium hypochlorite (2.5%) was used for the sterilization of bracts segments, with or without previous immersion in alcohol 70%. For callus induction, bracts segments were inoculated on MS medium with different concentrations of BAP and NAA. For buds induction, callus were inoculated on MS medium with different concentrations of cytokinins BAP, 2iP, and KIN (0.0 mg L^-1, 0.5 mg L^-1, 1.0 mg L^-1, and 2.0 mg L^-1). For multiplication, nodal segments from in vitro plants were inoculated in MS medium with BAP, KIN, and 2iP, in the concentrations of 0.0 mg L^-1, 0.5 mg L^-1, 1.0 mg L^-1, and 2.0 mg L^-1. For rooting, nodal segments from in vitro plants were inoculated using two MS medium dilutions: full strength and half strength of MS basal salt mixture (macronutrients salts) and different concentrations of IBA (0.00 mg L^-1, 0.25 mg L^-1, 0.50 mg L^-1, and 1.00 mg L^-1). The best sterilization treatment was achieved by using calcium hypochlorite combined with immersion in alcohol. For callus induction, the MS medium with 0.4 mg L^-1 of NAA plus 4.0 mg L^-1 of BAP was more efficient. Bud multiplication was improved in MS medium with 0.5 mg L^-1 of 2iP or 1.0 mg L^-1 of KIN. The highest percentage of explants with roots without emission of callus was observed in the medium with 50% and 100% of MS salts without IBA.

KEY-WORDS: Disinfection; growth regulator; callus; rooting.