Tissue Culture of Gymnaster savatieri K. Using Planting Cell Tray with Solid Supporting Materials

Several kinds of solid supporting materials were compared with agar-solidified medium as supports for plantlets of Gymnaster savatieri K. The most suitable material was 1 : 1 mixture (by vol.) of perlite and vermiculite in trays with planting cells (Hereinafter referred to as PV tray medium). In vitro shoots in PV tray medium grew faster than the control shoots grown in agar-solidified medium, even when the volume of nutrient solution in the PV tray medium was less than that of the control. Of the concentrations tested, the most suitable concentration of macronutrients in the PV tray medium was a 1/1 strength of MS medium (1962), higher than the most suitable concentration in the agar-solidified medium.The most suitable duration of the last-stage of culture for quick growth of the plantlets after transfer to a greenhouse was investigated. Plantlets were cultured either in PV tray medium or on agar-solidified one for 3, 6, or 9 weeks. After the in vitro culture, the PV tray medium with plantlets were removed from the culture vessel and transferred to the green-house. Then, they were misted overhead with water for about 30 min. and grown under an intermittent water mist. The plantlets cultured on the agar-solidified medium were transplanted into plastic trays containing a 1 : 1 : 1 mixture (by vol.) of perlite, vermiculite, and peat moss and were grown under the same mist. The plantlets in the PV tray medium could be transferred efficiently and grown without contamination of the supporting material. After accommodation, the survival of the plantlets cultured in the PV tray medium was the same as that of controls. Regardless the kind of supporting material, plantlets transferred after 3 weeks of culture were largest at the end of accommodation. The plantlets grown in the PV tray medium for 3 weeks and then transferred to the greenhouse grew faster than those grown in the agar control for 6 weeks after transfer. PV tray medium can be used not only as an in vitro culture medium but also for the raising seedling.