Mitigating the scarcity of Dipterocarp seedlings

Tissue culture has been identified as a solution to achieve enough supply of resilient seedlings in our reforestation project. To understand further on how to achieve The replacement of native populations of trees with cultivated kinds is vitally necessary to fulfil the growing demand for forest products while more forest area is required for non-timber purposes. At the moment, short-rotation intense hardwood cultivation looks to be a good fit for this requirement.

Plantlet development from in vitro cultures of Hopea odorato Roxb. is described. Embryos excised from seeds and cultured on Gamborg's B5 or modified Murashige and Skoog (MS) medium with benzyladenine (BA, 2.2–22.2 μM) produced axillary shoots at cotyledonary and/or stem nodes. Shoot production was greatest in germinated embryos on modified MS medium with 8.9 μM BA. Excised axillary shoots formed few buds when cultured on medium with BA and limited root development occurred on Woody Plant Medium with naphthaleneacetic acid. Nodal explants from aseptically grown plantlets sprouted axillary shoots in modified MS medium with BA.

Plant tissue culture is a technique for cultivating plant cells, tissues, and organs in an aseptic environment on an artificial nutritional medium. A single cell may regrow a whole plant under the correct conditions. Tissue culture is recognized as a significant technique for developing countries in the creation of disease-free, high-quality planting material as well as the quick manufacture of large numbers of homogeneous plants. For large-scale plant multiplication, plant tissue culture technique is frequently utilised. Plant tissue culture techniques have recently gained industrial importance in the areas of plant propagation, disease treatment, plant development, and secondary metabolite synthesis, in addition to their use as a research tool.

2.0 Process of Tissue Culture

Small fragments of a specific plant tissue are used in this procedure. After obtaining the tissue, it is cultivated in the proper medium under sterile conditions to prevent bacteria from interfering with the procedure. A general technique for plant tissue culture is as follows:

• Medium preparation

The suitable combination is combined with distilled water and agitated while the sugar and sugar mixture are added in the right amounts. To alter the pH, sodium hydroxide or hydrochloric acid is employed. The amount of sodium hydroxide or hydrochloric acid used will depend on the plant being cultured and the quantity of tissues to be cultured. Agar is added to the liquid, which is then heated and stirred until it dissolves. The heated medium is put into polycarbonate tubes when it has cooled (to a depth of about 4 cm). The tubes are placed in a pressure cooker with covers on them and sterilised for 20 minutes.

• Plant preparation

Part of the plant should be chopped into tiny pieces about 1 cm across. Parts like the African violet leaves, on the other hand, can be utilised whole. Wash the plant portion for around 20 minutes with detergent and water. Place the plant part in a sterilising Clorox solution, shake for a minute, and then set aside for 20 minutes. Gently dump the Clorox with a lid while keeping the plant portion in the container, then cap the container.

• Transferring plant material to cultured medium

Open the jar and pour enough sterile water to fill it halfway. Cover the container with a sterile cover and shake it for 2 to 3 minutes to wash the tissue and remove the bleach. Pour the water three times and continue the process. Remove the plant portion from the container and place it in a sterile Petri dish using sanitised hands. Cut the plant material into smaller pieces of about 2 to 3 mm across using a sterile blade, avoiding the areas that have been destroyed by bleach. Place a portion of the plant in the medium using sterile forceps.

3.0 Problems of Tissue Culture for Forest Plant

• Browning

The oxidation of phenolic compounds leached out from the cut surface of the explants, which makes the medium dark brown and is poisonous to the tissues, is a major concern when cultivating adult tissues from woody species. Browning is a process in plant tissue culture when explants leak brown compounds or phenolics into the media from their own tissues during dedifferentiation and/or re-differentiation. It lowers the rate of cell division and explant regeneration ability, resulting in the death of cultured tissues and failure of plant tissue culture.

Prevention of browning will require technics ro remove inhibitory chemicals from the medium efficiently, reducing toxic metabolites, phenolic exudation, and brown exudate build up. While phenolic compounds are found in healthy plant tissues and can accumulate in specialised cell types, they are generated in larger quantities and/or released as a defensive response, particularly in the aftermath of tissue wounding or stress. The bulk of tissue culture methods involve wounding the material to extract explants and cultured them in potentially stressful conditions, which frequently results in the synthesis and release of phenolic chemicals. To avoid browning of the medium or explant, the antioxidant lowers the oxidised substrate. Before starting the culturing procedure, make fresh solutions each time.

For more information about our tissue culture and seedlings replication, please email : nirwana@planters.life