In vitro Studies on the Effect of Light Intensity on Plant Growth of Phaius tankervilliae (Banks ex L' Herit.) Bl. and Vanda coerulea Griff

Abstract

The effect of light intensity on plant growth of Phaius tankervilliae and Vanda coerulea was investigated in vitro. Plantlets of P. tankervilliae and V. coerulea with leaves of 2 cm. long were cultured on suitable medium under different light intensities of 28, 37, 56, 74 and 93 µmol m -2 s -1 . Plantlets of P. tankervilliae were cultured on modified Vacin & Went medium, supplemented with 100 g/l of banana without saccharose. Plantlets of V. coerulea were cultured on modified Vacin & Went medium, supplemented with 100 g/l of banana, 100 g/l potato extract and 20 g/l saccharose. The environment for all growth in vitro was maintained at 25° ± 2°C, with a 16-h photoperiod. Plant growth was observed two months after culturing. Dry matter accumulation, plant height, leaf number and leaf area development of these two species of plantlets were best at the light intensity of 74 µmol m -2 s -1 .