Plant tissue culture is the technique of growing plants cells , tissues ,protoplasts or organs aseptically on artificially prepared nutritive medium in suitable container under controlled environmental conditions .So it is in vitro growth ,development and differentiation of plant cells ,tissues, protoplast or organs. The parts of plants used in tissue culture are called explants. It is widely used to produce clones of a plant in a method known as micro propagation. It is based on the principle of cellular totipotency given by Gottleib Haberlandt.
According to principle of cellular totipotency,“Each somatic cell of a plant has a capacity of development of whole plant’’ .Based upon the principle of cellular totipotency F.C. Stewart developed whole carrot plant from few cells in a cultured medium.
TYPES OF PLANT TISSUE CULTURE
Callus is the mass of undifferentiated and unorganized cells. Callus culture is a process of development of whole plant from callus.
In this process apical or auxillary shoots is used as explants.
In this process embryo of plants kept at nutritive medium is used as explant.Embryo Plants
In this process roots kept in cultured medium is used as explant .
It is a process of development of haploid plant after keeping anther with pollen grains in nutritive media. This process is also called androgenesis.
6. PROTOPLAST CULTURE
7.MERISTEM TIP CULTURE –
It is the technique of development of plant by keeping the tip of apical meristem in nutritive medium.It is highly used in the production of virus free plants.
METHODS OF TISSUE CULTURE
1.Constituents of tissue culture medium
Constituents of cuture medium should be prepared .The tissue culture medium should contain following ingredients.
Inorganic elements = Fe,Cu,Zn,Mb micronutrients
Organic compounds=carbohydrates,protein and amino acids .
In addition to above elements other ingredients required are vitamin , auxin , gibberellins and cytokinin and agar .
2. Preparation of tissue culture medium
Tissue culture medium are prepared in the form of stock solution. For preparation of stock solution distilled water and chemicals of high purity are used. The various concentrations of liquid stock solution are developed by mixing organic compounds , inorganic compounds, semi synthetic compounds, vitamins, plant growth hormones and agar .
3. Selection of tissue culture media
Different types of explants needs different concentrations of stock solution. To select the suitable concentration of stock solution, broad spectrum experiments are set up.
The process of removal of pathogenic agents so as to prevent the the explants from inhabiting its growth and death is called sterilization. It includes various process such as UV radiation, laminar air flow method , sterilization by ethyl solution and various more.
5. Micro propagation
It is the process of development of whole plants from explants . It is also called in vitro clonal propagation.
Young plants is then transferred in the soil of pot. High humidity (90-100%) should be maintain for 15 days.
ADVANTAGES OF TISSUE CULTURE
1.It is used in the production of genetically alike plants.
2.It is used in the production of matured plants.
3.Used in the production of multiples of plants in the absence of seeds or necessary pollinators to produce seeds.
4.Anther culture is useful for genetically analysis and plant breeders to develop haploid plant or homozygous diploid plants by treating colchicine in nutritive medium.
5.Meristem culture is highly used to produce virus free plant
6.Multiple buds are raised directly from the explants without any callus formation by using the technique of tissue culture.
7.The method is used for the propagation of endangeres species .
8.Somatic embryos are embryos that are derived from vegetative cells in tissue culture .The formation of embryo like structure on the cultured callus tissue is practiced by this technique .
9.Usually production of pure line character is a tedious process that involves successive selfing for successive generations. So production of pure line character is practiced by tissue culture.
10.Jinghua 1 ,winter wheat and Guan 18, rice was developed from anther culture.
11.The tolorent cells developed from tissue culture can be used for raising herbicide resistant ,salt resistant ,or toxin resistant plants.
12.Embryo mortality and seed collapse can be prevented by tissue culture.
13.Production of artificial seed is practiced by tissue culture.
14.Production of alkaloids , terpenoids, steroids, anthocynins,etc are due to cell culture.
- Due to continuous self breeding the offspring thus produces are less resistant to diseases than its parent plant.
2 .It requires sophisticated lab which is not always possible in economically backward countries.
3. The quality of product of new plants are comparatively poorer than its parent one