ISSN 1311-9109 Journal Content

International Symposium
on Production and Establishment of Micropropagated Plants
April 19-24, 2015,
Sanremo, Italy

Propagation of Ornamental Plants
10(4): 227-236, 2010


Quynh Thi Nguyen*, Thang Van Hoang, Hien Nhu Nguyen,
Sy Dinh Nguyen, and Duc Huu Huynh

Institute of Tropical Biology, VAST, Hochiminh City, Vietnam,
*Fax: + 84-8 3897 8791, *E-mail:

Effect of different ventilation rates and light intensities on photoautotrophic growth of Dendrobium ‘Burana White’ were investigated using both natural and forced ventilation methods. All explants were cultured on the sugar-free half strength MS liquid medium without vitamins and plant growth regulators, and supplemented with substrate perlite as supporting material. In the first experiment, all in vitro plants in natural ventilation were put in 370 ml Magenta box-type vessels having two different number of air exchanges, 3.5 or 4.9 h-1, and under three different photosynthetic photon fluxes (PPFs), 50, 80 or 110 µmol m-2 s-1. In the second experiment, in vitro plants were cultures in either natural ventilation system with 370 ml Magenta box-type vessels or forced ventilation system with 7 l vessels (Bio-Safe Carrier box). The number of air exchanges of small vessels was 3.7 h-1, whereas, for the large vessel, the number of air exchanges was regulated from 2.6 h-1 to 13.7 h-1. In vitro plants grown photoautotrophically in the natural ventilation under PPF of 110 µmol m-2 s-1 and in the vessel having high ventilation rate (4.9 h-1) showed the highest increase in fresh and dry weights on day 65. Plants cultured in the treatment of low PPF (50 µmol m-2 s-1) and low ventilation rate (3.5 h-1) showed lower chlorophyll a/b ratio than those in the other treatments. On day 40, the in vitro plants grew faster in forced ventilation with a remarkable increase in fresh and dry weights than in natural ventilation. The net photosynthetic rate, percent dry matter and total chlorophyll contents of the plants cultured in forced ventilation were also significantly higher than those of plants grown in natural ventilation.

Key words: carboxylation, Dendrobium ‘Burana White’, forced ventilation, natural ventilation, photosynthesis, stomatal closure

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