[Biology Class Notes] on Tissue Culture Pdf for Exam

Tissue Culture is a method under which fragments of plants and animal Tissues are cultivated and grown in a laboratory. The organs, many times, are used for Tissue Culture. Broth and agar are the media used for the growth of the Culture. This method is also known as micropropagation. a sterile workplace, a greenhouse, trained manpower, and a nursery are all it requires. It is beneficial for the production of disease-free plants and plants in developing countries. In developing countries, oil palm, banana, plantain, eggplant, pineapple, rubber tree, tomato, sweet potato have been produced by Tissue Culture. 

Following are the main categories of Cultures:-

• Primary Culture:- These model the natural function of the Tissue and are generally mortal. They consist of natural Tissues excised from the living organisms by biopsy.

• Culture of Established Cell Lines:- These are derived from tumor biopsies, or from the primary cells that had undergone mutation and continued to replicate.

Types of Tissue Culture.

Listed below are some types of Tissue Culture techniques:-

• Seed Culture:- In seed Culture,  explants are obtained from an in-vitro derived plant and hence are introduced into a laboratory where they proliferate. To prevent the plants from Tissue damage it should be sterilized.

• Embryo Culture:- Embryo Culture involves the in-vitro development of an embryo. For this process, an embryo is isolated from and living organism, both a mature and an immature embryo can be used. Mature embryos can be obtained from ripe seeds whereas immature embryos are obtained from the seeds that failed to germinate. The ovule, seed, or fruit has already been sterilized, hence there is no need to sterilize them.

• Callus Culture:- A callus can be defined as an unorganized, dividing mass of cells. A callus is the explants are Cultured in a proper medium good. The growth of callus is followed by organ differentiation. This Culture is grown on a gel-like medium composed of agar and specific nutrients which are required for the growth of the cells.

• Organ Culture:- In organ Culture, any organ of the plant such as a shoot, the leaf can be used as an explant. Many methods can be used for the organ Culture such as the plasma clot method, raft method, the grid method, and Agar gel method. This method can be used to preserve the structure and functions of an organism.

• Protoplast Culture:- It can be defined as a cell without a cell wall. The hanging-drop method or micro-Culture chambers can be used to Culture a protoplast. A number of phases can be observed in protoplast Culture, development of cell walls, cell division, regeneration of a whole plant. 

• Suspension Culture:- suspension Culture can be defined as a form of Culture in which single cells or small aggregates of cells mul­tiply while suspended in an agitated liquid medium. It can also be called cell Culture or cell suspension Culture.

• Meristem Culture:- meristems have the main function of the production of new cells and the synthesis of protoplasm. Shoot meristem consists of a group of certain actively dividing cells that are being protected by the developing leaves.

Animal Cell Culture

Cell Culture is the process by which cells are grown in a controlled artificial environment. The cells are taken from the organ of an experimental Animal, for Animal cell Culture. The cells may be removed directly or by mechanical or enzymatic action. Fibroblasts, lymphocytes, cells from cardiac and skeletal tissues, cells from the liver, breast, skin, and kidney, and different types of tumor cells, are some examples of the cells used in the Culture.

Steps of Tissue Culture

Following are the steps of Tissue Culture:-

Initiation Phase:-

This is a stage when the Tissue is initiated into the Culture. To prevent the process from any contamination the Tissue of interest is obtained, introduced, and sterilized.

Multiplication Phase:-

In the multiplication stage, The sterilized ex-plant is introduced into the medium which consists of growth regulators and appropriate nutrients, they are responsible for the multiplication of cells. Hence this undifferentiated mass of cells is known as a callus.

Root Formation:-

This is the stage when the root starts forming. To initiate the formation of root plant growth hormones are added.  Consequently,  complete plantlets are obtained.

Shoot Formation:-

For the formation of the shoot, plant growth hormones are added and growth is observed for a week.

Acclimatization:-

When the plant starts to develop,  the plant is transferred to a greenhouse for it to develop under controlled environmental conditions. Thereafter it is finally transferred to the nurseries for its growth under natural environmental conditions.

Tissue Culture

Tissue Culture is the process of growing Tissues or cells outside of the parent organism in an artificial medium. Micropropagation is another name for this technology. A liquid, semi-solid, or solid growth medium, such as broth or agar, is generally used to aid this. Tissue Culture is a general phrase for the cultivation of animal cells and tissues, whereas plant Tissue Culture is a more specific term for the cultivation of plants. American pathologist Montrose Thomas Burrows invented the term “Tissue Culture. Plant Tissue Culture is based on the ability of plant Tissue to produce an entire new plant when given the right growth media and conditions. The ability of plant cells or Tissues to be totipotent is referred to as “totipotency.”

Process of Tissue Culture for Producing New Plants 

• A little piece of plant Tissue is extracted from the plant’s growth point or tip and deposited on a sterile jelly containing nutrients and plant hormones. Hormones cause the cells in plant Tissue to divide rapidly, producing a large number of cells that create a shapeless lump of material known as a ‘callus.’

• The callus is then placed in another jelly that contains plant hormones that encourage the callus to grow roots.

• The callus with roots is then placed on a jelly containing several hormones that stimulate the growth of new shoots.

• The callus, which has roots and shoots, divides into small plantlets. From a few initial plant cells or Tissue, many miniature plantlets are created in this method.

• The plantlets are then transplanted into pots or into the ground, where they can grow into adult plants.

Advantages of Tissue Culture

• On a large-scale bioreactor, the biochemical engineer can grow plant cells in liquid culture.

• The time it takes to establish consistent homozygous lines and varieties is reduced when dihaploid plants are grown from haploid Cultures.

• The ability to transfer and express new diversity in household crops is increased by crossing distantly related species using protoplast isolation and somatic fusion.

• Cell selection improves the number of people who can be screened in a given program.

• Micropropagation techniques such as meristem and shoot Culture allow for the development of a high number of homogeneous individuals from a small amount of starting material.