The fusion product of protoplasts without nucleus of different cells is called a cybrid.

Secondary Metabolites	Medicinal use
Capsaicin	Rheumatic pain treatment
Vincristine	Anti-carcinogenic
Quinine	Anti-malarial

Macronutrients:
(a) Ammonium nitrate
(b) Potassium nitrate
(c) Calcium chloride
Micronutrients:
(a) Manganese sulphate
(b) Zinc sulphate
(c) Potassium iodide

Redifferentiation	Dedifferentiation
A process by which an already differentiated cell undergo further differentiation to form another cell type	A process of reversion of cells (differentiated cells) to meristem state leading to callus formation is called dedifferentiation it.
Differentiated cell ➝ meristem state ➝ New cells

Cryopreservation (- 195.C)
1. Cryopreservation, also known as Cryo conservation.
2. A process by which protoplasts, cells, tissues, organelles, organs, extracellular matrix, enzymes or any other biological materials are subjected to preservation by cooling to very low temperature of -196^oC using liquid nitrogen.
3. At this extreme low temperature any enzymatic or chemical activity of the biological material will be totally stopped and this leads to preservation of material in dormant status.
4. Later these materials can be activated by bringing to room temperature slowly for any experimental work.
5. Protective agents like dimethyl sulphoxide, glycerol or sucrose are added before cryopreservation Process.
6. These protective agents are called cryoprotectants, since they protect the cells, or tissues from the stress of freezing temperature.

Somatic embryogenesis is the formation of embryos from the callus tissue directly and these embryos are called Embryoids or from the in vitro cells directly form pre-embryonic cells which differentiate into embryoids
Applications:
i. Somatic embryogenesis provides potential plantlets which after hardening period can establish into plants.
ii. Somatic embryoids can be used for the production of synthetic seeds.
iii. Somatic embryogenesis is now reported in many plants such as Allium sativum, Hordeum vulgare, Oryza sativa, Zea mays and this is possible in any plant.

1. The growing of cells including the culture of single cells or small aggregates of cells in vitro in liquid medium is known as cell suspension culture.
2. The cell suspension is prepared by transferring a portion of callus to the liquid medium and agitated using rotary shaker instrument.
3. The cells are separated from the callus tissue and used for cell suspension culture.

Sterilization of Nutrient Media:
1. Culture media are dispensed in glass containers, plugged with non-absorbent cotton or sealed with plastic closures and then sterilized using autoclave at 15 psi (121^o(C)  for 15 to 30 minutes.
2. The plant extracts, vitamins, amino acids and hormones are sterilized by passing through Millipore filter with 0.2 mm pore diameter.
3. Then added to sterilized culture medium inside Laminar Airflow Chamber under sterile condition.
Other techniques used to remove the microbes
(a) Maintenance of aseptic environment
(b) Sterilization of culture room
(c) Sterilization of explants

(a) Murashige and Skoog medium
(b) Gamborg medium
(c) White medium
(d) Nitsch's medium

Sterilization is the technique employed to get rid of microbes such as bacteria and fungi in the culture medium, vessels and explants.

Growing plant protoplasts, cells, tissues or organs away from their natural or normal environment, under artificial condition, is known as Tissue Culture.

Pineapple, banana, strawberry and potato.

Artificial Seed
1. Artificial seeds or synthetic seeds (synseeds) are produced by using embryoids (somatic embryos) obtained through in vitro culture.
2. They may even be derived from single cells from any part of the plant that later divide to form cell mass containing dense cyptoplasm, large nucleus, starch grains, proteins, and oils etc.
3. To prepare the artificial seeds different inert materials are used for coating the somatic embryoids like agrose and sodium alginate.

Basic concepts of Tissue Culture
Basic concepts of plant tissue culture are totipotency, differentiation, dedifferentiation and redifferentiation.
Totipotency
The property of live plant cells that they have the genetic potential when cultured in nutrient medium to give rise to a complete individual plant.
Differentiation
The process of biochemical and structural changes by which cells become specialized in form and function.

Redifferentiation
The further differentiation of already differentiated cell into another type of cell. For example, when the component cells of callus have the ability to form a whole plant in a nutrient medium, the phenomenon is called redifferentiation.
Dedifferentiation
The phenomenon of the reversion of mature cells to the meristematic state leading to the formation of callus is called dedifferentiation. These two phenomena of redifferentiation and dedifferentiation are the inherent capacities of living plant cells or tissue. This is described as totipotency.