Tissue Culture

Tissue culture is a method to grow cells from plants or animals in a lab under sterile and controlled conditions. Small tissue pieces (explants) are placed in a sterile and nutrient-rich medium.

For plants, this is called micropropagation. It helps make many healthy and identical plants fast.

What is Tissue Culture?

Tissue culture is a process where a small piece of a plant is taken. This small piece is called an explant. The explant is placed in a special nutrient-rich medium.

This medium can be gel-like (agar) or liquid (broth) and contains minerals, vitamins, and plant hormones that support tissue growth.

When conditions are just right, the cells start dividing and form new tissues, which can grow into complete plants.

This technique works well because many plant cells can develop into full plants. Even a tiny piece of leaf or stem can produce many healthy new plants through tissue culture.

Types of Tissue Culture

There are different types of tissue culture depending on what is being grown:

Seed Culture - Seeds are grown in sterile conditions to produce clean seedlings.
Embryo Culture - Embryos, either mature or immature, are grown when natural seed germination does not happen properly.
Callus Culture - A soft group of unorganised cells (callus) is formed from a plant part. This callus can later grow into roots or shoots.
Organ Culture - Plant parts like shoots, leaves, or roots are grown while keeping their structure and function.
Protoplast Culture - Protoplasts are plant cells without walls. These are grown to form new cells and plants. This method is useful in experiments and genetic changes.

Other Types:

Pollen or Anther Culture - Used to grow haploid plants from male cells.
Suspension Culture - Cells float and grow in a liquid medium.
Somatic Embryogenesis - Non-reproductive cells turn into embryos and then full plants.

Steps of Tissue Culture

Initiation Phase

A small plant tissue is selected, cleaned, and sterilised to remove germs.

Multiplication Phase

The tissue is placed in a medium that helps cells divide. This forms a callus (a mass of cells).

Shoot Formation

Other hormones are used to help shoots grow. This forms tiny plantlets.

Root Formation

Special hormones are added to help the callus grow roots.

Acclimatization

The plantlets are moved to a greenhouse and slowly adjusted to natural conditions. Later, they are planted in soil to grow normally.

Advantages of Tissue Culture

Many plants can be grown in a short time.
The plants are clean and free from diseases.
Plants can be grown all year round.
Only a small space is needed for large-scale production.
Rare or endangered plants can be saved.
Used to grow beautiful plants like orchids and useful crops like bananas and tomatoes.

Importance of Tissue Culture

Tissue culture is important in many fields:

Agriculture - Helps farmers grow better crops faster.
Genetic Research - Used to add or change traits in plants.
Plant Conservation - Saves plants that are rare or nearly extinct.
Medical Research - Animal tissue culture (a separate process) is used to study cells, test medicines, and produce vaccines.

Summary

Tissue culture is a way to grow plants from tiny parts in a lab. It helps make many healthy, disease-free plants quickly. The process is used in farming, research, and saving rare plants. It can be done year-round under controlled lab conditions. It requires less space compared to field cultivation.