Direct somatic embryogenesis from leaf, petiole and rhizome explant of Panax vietnamensis Ha et Grushv.

Abstract

Panax vietnamensis is one of the most valuable medicinal plants in Vietnam. In recent years, there has been an increasing interest in propagation and conservation of this plant. This paper attempts to show that direct somatic embryogenesis using the thin cell layer technique is an effective method for micropropagation of P. vietnamensis. This success was mainly resulting from the ability to develop into complete plants, together with the shortening of culture time. In this paper, three sources of explants (leaves, petioles and main roots) of 3-month-old in vitro plantlets of P. vietnamensis were cultured on MS medium supplemented with NAA and 2,4-D at various concentrations (0.1, 0.2, 0.5, 1.0 and 2.0 mg.l-1). After 10 weeks of culture, the results showed that among three types of explants used, leaf explants were optimal for direct somatic embryogenesis. Leaves cultured on MS medium supplemented with 2 mg.l-1 NAA gave the highest frequency of direct somatic embryogenesis. Histological study showed the normal development phases of somatic embryos of P. vietnamensis.