English

Abstract

Being a tropical country, Vietnam has an exceptional diversity of medicinal plants, particularly in the highland provinces (for example, Lam Dong, Daklak and Kontum provinces). However, a list of many rare medicinal plants are recorded in the Vietnamese Red Data Book and most of them are globally threatened. In this study, the effect of the type of culture media and the concentration of phytohormones on germination, shoot height and shoot number derived from Codonopsis javanica (Blume) Hook f. & Thomson synthetic seeds were evaluated under laboratory conditions. The germination rate and shoot-formatting potential of C. javanica artificial seeds were greatly affected by the components of plant tissue culture media after 40 days of sowing. Particularly, germination rate of Codonopsis artificial seeds was maximum when they were sown in hormone-free Murashige and Skoog (MS) medium in comparison with other culture media (1/2 MS, 1/2 Schenk and Hide-brandt (SH), and SH). Addition of 1.0 mg l-1 N-6-benzyladenine (BA) and 0.1 mg l-1 naphthaleneacetic (NAA) into MS medium led to increased shoot height, shoot number and germination percentage of the synthetic seeds compared to other concentrations of these phytohormones. The height of shoots derived from the synthetic seeds was inhibited according to the increase of supplemented abscisic acid (ABA) concentration in MS medium. The best planting medium to use to germinate the artificial seeds of C. javanica and to increase their shoot-forming potential was the MS supplemented with 1 mg l-1 BA and 0.1 mg l-1 NAA. The study is expected to provide new insights into the application of synthetic seeds in rapid multiplication of Vietnamese C. javanica, establishing the traditional herbal medicine resource for human demands. Key words: Medicinal plant, Codonopsis javanica, artificial seed, plant tissue culture medium.