Effects of CO2 concentration, PPFD and sucrose concentration on Cymbidium plantlet growth in vitro

摘要

The effects of CO2 concentration (500 or 1000mol/mol) and photosynthetic photon flux density (PPFD; 50 or 100mol m-2 s-1) on the growth of leafy Cymbidium (cv. Marilyn Monroe) protocorm-like bodies (PLBs), cultured in vitro for 42 days on a half-strength Murashige and Skoog medium with or without sucrose (0 or 30 g/litre), were investigated. On day 15, all plantlets were transferred to new media with or without sucrose. On day 42, fresh weight, dry weight (DW), leaf area per plantlet and net photosynthetic rate (per total DW) were significantly greater under conditions of high CO2 concentrations and high light intensities compared with conventionally grown plantlets (500mol/mol CO2, 50mol m-2 s-1 PPFD and media with sucrose before and after day 15). It was concluded that Cymbidium plantlets could be grown effectively on a medium without sucrose (photoautrophically) under enriched CO2 and high PPFD conditions.