Plant Propagation

Micropropagation is the art and science of plant multiplication in vitro.

Micropropagation is a method of propagating plants that uses very small parts of plants that are grown in sterile culture. There are generally four stages involve in Micropropagation:

STAGE 1 -Preparation of the explant and establishment of the aseptic culture.

STAGE 2 – Shoot Multiplication.

STAGE 3 – In vitro rooting (pretransplanting)

STAGE 4 – Transfer to soil; Transplanting and acclimatization of the plantlets in soil.

The techniques that can be applied to ornamental plants propagated in vitro:

1. Shoot-tip culture

2. Meristem-tip culture

3. Single node culture

4. Axillary bud culture

5. Micrografting

The nutrient medium used for plant tissue culture should consist of:

Inorganic salts (macro and micro elements)
A carbon source (sucrose or glucose
Vitamins (thiamine, nicotinic acid, myo-inositol and others)
Growth regulators (auxin and cytokinins)
*Agar (a gelling agent) is added to the medium if a solid medium is needed, and it is omitted if a liquid medium is used.

What are the advantages of this?

Production of many plants that are clones of each other.
Can be used to produce disease-free plants.
It produces rooted plantlets ready for growth, saving time for the grower when seeds or cuttings are slow to establish or grow.
It is the only viable method of regenerating genetically modified cells.
It is useful in multiplying plants which produce seeds in uneconomical amounts, or when plants are sterile and do not produce viable seeds or when seed cannot be stored.
Produces more robust plants, leading to accelerated growth compared to similar plants produced by conventional methods – like seeds or cuttings.
Some plants with very small seeds, including most orchids, are most reliably grown from seed in sterile culture.
A greater number of plants can be reproduced in a smaller area.

What are the disadvantages?

Micropropagation is not always the perfect means of multiplying plants. Conditions that limits its use include:

It is very expensive, and can have a labor cost of more than 70%
An infected plant sample can produce infected progeny. This is uncommon as the stock plants are carefully screened and vetted to prevent culturing plants infected with virus or fungus.

The major limitation in the use of micropropagation for many plants is the cost of production.