The role of natural light within vitro propagation of orchid and banana

The development of high-tech agriculture in Da Lat, Ho Chi Minh City and many other provinces and cities throughout the country placed an increasing demand of growing transplants using in vitro method. In vitro propagation helped to create transplants which were free from disease, highly- resistant and able to produce transplants within great scope quickly and easily. Therefore, in vitro propagation brought about big economic profits.

At the Institute of Tropical Biology, researchers succeeded in providing a comprehensive process for anamorphic in vitro propagation of orchid and banana which were grown under natural light and temperature. When cultivated in nursery garden, the trees adapted to external conditions more quickly than those in a cooling room filled with artificial light.

This method was used not only to reduce production prices without the need to use the light and cooling electricity but also to “temper” the transplants to partially adapt to the natural conditions.

Following previous research results in tissue culture under the natural light, completing anamorphic in vitro propagation of orchid and banana under natural light and temperature was one step to narrow the distance from scientific research results to the farmers, to allow the transfer of technical advances within vitro tissue culture to rural households and to apply technical science for high-tech agricultural production.

The formula of growing in a room lighted by 2000 lux using fluorescent lamp with 8 hours of lighting per day and a temperature of 28°C±3 was clearly different from the formula using natural light at the galery or plastics house. The natural light was different from lamp one in the point that light intensity changed continuously within the day from 500 to 7000 lux. The day and light temperature also changed continuously and the amplitude of fluctuation in natural light was 29°C ±8, much greater than that in cooling room, thus air exchange increased. The stronger air exchange was, the faster and stronger the tree became. However, strong air exchange would create higher infection if the process was not properly supervised. To reduce infection risks, the researchers completely removed sugar from the growing environment and at the same time supplemented starch to make the trees grow quickly and retain growth rate on one hand, and to reduce infection in natural temperature and light on the other hand.


Growing in vitro trees in natural light and temperature in which the sun shines directly onto the trees for some minutes.


The experiments were conducted in a Laboratory of Plant Cell Technology, Ho Chi Minh city, Institute of Tropical Biology, Vietnam Academy of Science and Technology.


The general view of growing plastic house in natural light and temperature researched and carried out by Bio -Agritech Co.,Ltd. The whole house was put under the tree canopy. The sun house was designed in order  in early morning and afternoon could directly shine into tissue culture vases.




Dendrobium in different carbohydrate sources and lighting regimes
A. Natural light + starch          B. Lamp light + starch.
B. Natural light +sugar.        D. Lamp light +sugar.


Dendrobium or Dendrboium orchid under natural light was stronger, greener and fatter than that grown in the room.


60 year-old Doritaenopsis
A. Natural light + starch   B. Lamp light + sucrose sugar.


La Ba banana (Cavendish sp.)


In recent years, the demand of growing tissue cultured banana has been especially developed in Da Lat. La Ba banana, and aromatic banana Cavendish sp. are easy grown with little care and no worry about the output for products.


21-year-old banana


The period of using natural light was the final month before the tree was brought to be grown in a nursery garden. Although this process was shorter than the propagation one, the tree vase amount accounted for 50-70% of total tissue culture vases of the manufacturing unit because transplants were propagated in geometric series.


A banana propagated through in vitro tissue culture grown in nursery garden for 2 months.


For orchid species with slow growth rates, cultivation under natural light and temperature decreased the energy consumption burden, especially in current power conditions. This measure promoted sustainable production.

Especially, for the aromatic banana, Cavendish sp. La Ba genus, the process mentioned above was an important comprehensive step to propagation in industrial scope.


Translated by Hoang Lien
Link to Vietnamese Version

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