Define the term tissue and explain the concept of tissue culture.

Groups of cells performing the same function are known as tissues.

Plant tissue culture is the production of new plants from small amounts of plant tissue under carefully controlled laboratory conditions. In this method, some plant tissues are taken under sterile conditions and are kept in test tubes containing culture medium, which allows these cells to grow fast and form an unorganised mass of cells called callus. This callus is transferred into another medium containing proper growth hormones for differentiation and organ formation. As a result, small plantlets are formed in the test tubes. These can be later placed in soil where they can grow into mature plants. This technique is called micro-propagation.

Tissue culture

Tissue culture has various applications like:

(i) It is used to produce disease resistant and high yielding varieties of plants.

(ii) Tissue culture is helpful to produce new varieties of plants by fusing two different cells through a technique called germplasm hybridisation and then growing the fused cells through tissue culture. For example: Pomato.

(iii) Tissue culture along with recombinant DNA technology has made it possible to transfer nitrogen fixing genes from bacteria into plants. This has helped these plants to fix atmospheric nitrogen.

(iv) It helps to produce large number of plants in short duration of time and in limited space.

(v) It has made it possible to preserve characteristics of the parent plants.