Terminology

Aseptic technique: Procedures performed under sterile conditions to prevent the introduction of microorganisms such as fungi, bacteria, viruses and phytoplasmas into cell, tissue and organ cultures, and cross contamination of cultures.

Callus: An unorganized mass of undifferentiated plant cells.

Cell culture: A culture of cells or their maintenance in vitro including the culture of single cells.

Clonal propagation: Asexual multiplication of plants from a single individual or explant.

Clones: A group of plants propagated from vegetative parts, which have been derived by repeated propagation from a single individual. Clones are considered to be genetically uniform.

Culture: A plant growing in vitro in a sterile environment.

Differentiated: Cells that have developed into specialized structures and organs.

Explant: An excised piece or part of a plant used to initiate a culture.

Ex vitro: Outside glass, for example plants removed from tissue culture and transplanted to soil or potting mixture.

Hormones: Naturally occurring substances, signal molecules, which are secreted by specialised cells that affect the metabolism or behaviour of other cells possessing functional receptors for the hormone. Plant hormones (or plant growth regulators, PGR) can be naturally occurring hormones or chemically synthesised and are used to regulate plant growth.

In vitro: To be grown inside glass, usually a petri dish, test tube or container. Also refers to studies of biological properties that are done in a test tube (i.e. under glass).

In vivo: Refers to studies of biological properties that are performed inside a living organism.

Laminar Flow Hood: An enclosed work area where the air is cleaned using HEPA filters.

Medium: A solid or liquid nutrient solution used for culturing cells.

Micropropagation: Multiplication of plants from vegetative parts by using tissue culture nutrient medium.

Multipotent cell: A cell that has the ability to differentiate to a limited number of cell fates or into a closely related family of cells.

Plant growth regulators: See Hormones.

Pluripotent cell: A cell that has the ability to differentiate into many cell types.

Stem cell: A cell that has not yet acquired a special function. An unspecialized cell that can self-renew by cell division while in an undifferentiated state, and that can give rise to various cell types by cell differentiation.

Undifferentiated cell: See stem cell.