Artificial propagation (tissue culture)

Artificial propagation (tissue culture)

1. 1) a small piece of tissue is taken from the plant to be cloned, usually from the shoot tip. This is called an explant.

   • 2) The explant is placed on nutrient growth medium.
     • 3) Cells in the tissue divide but they do not differentiate. Instead they form a mass of undifferentiated cells called a callus.
       • 4) After a few weeks single callus cells can be removed from the mass and placed on a growing medium containing plant hormones that encourage shoot growth.
         • 5) After a further few weeks the growing shoots are transferred to a medium containing hormones that encourage root growth.
           • 6) the growing plants are then transferred to a greenhouse to be acclimatised and grown further before they are planted outside.

2. Advantages

   • Farmers know what the crop plant produced will be like because it is cloned from plants with known features such as high yield, taste, colour and disease resistance.
   • Farmer's costs are reduced because all the crop is ready to be harvested at the same time.
   • Faster than selective breeding because huge numbers of plants can be generated from a snle valuable plant.

3. Disadvantage

   • Genetic uniformity meaning reduced resistance to disease, pest or environmental change.