PHOTOAUTOTROPHIC MICROPROPAGATION OF CYMBIDIUM PLB

Abstract

Cymbidium (cv. Lisa rose) PLB (protocorm-like bodies) were cultured in liquid 1/2 MS medium with/without 20 mg g-1 sucrose under continuous lighting conditions. The vessels were shaken at 100 rpm under PPF (photosynthetic photon flux) of 20 and 140 μmol m-2 s-1 and CO2 concentrations outside the vessel (Cout) of 450 and 2000 μmol mol-1 conditions. Photoautotrophic growth was obtained at high PPF and high Cout. The chlorophyll content of the PLB in the medium without sucrose at high PPF and high Cout was almost 3 times that with sucrose at low PPF and low Cout. The number of newly developed PLB with sucrose at low PPF and low Cout was 1.6 times that without sucrose at high PPF and high Cout; the dry weight per unit PLB with sucrose at low PPF and low Cout was almost 3 times that without sucrose at high PPF and high Cout. Photoautotrophic growth of the PLB might be further promoted at higher CO2 concentration (> 1%).