Question

Hardening in tissue culture is
(a) Keeping at 30-50C temperature for about 30 minutes
(b) Acclimatisation of tissue culture plants slowly before growing in the field
(c) Plunging the vials into water at 37-40C
(d) None of the above

Answer 1

Hint: Tissue culture is the separate growth of cells and tissues, away from the parent organism. Tissue culture takes place in an artificial growth medium.

Complete Answer:
Plant tissue culture is the assimilation of many techniques that are utilized in the maintenance or growth of plant cells and tissues. Plant tissue culture is carried out under extremely sterile conditions, in a nutrient medium for the growth of the cells or tissues. Micropropagation of plant cells and tissues is a widely used method for the production of clones of various different plants.
Plant tissue culture utilizes the ability of most plant cells that can generate a new plant from a single cell. This ability of generation of an entire plant from a single plant cell is known as totipotency.
Hardening is the incubation of plants in netted plastic pots for 6-8 weeks in a greenhouse. These plants are incubated in a liquid nutrient medium.
Therefore hardening is the acclimatisation of tissue culture plants slowly before growing in the field.

Hence the correct option is (b) Acclimatisation of tissue culture plants slowly before growing in the field.

Note:
The growth medium usually used in tissue culture is either a liquid, solid or semi-solid growth medium. These growth mediums are typically broth or agar. Tissue culture is also known as micropropagation.
The term tissue culture refers to both animal cells and plant cells collectively. The specific tissue culture of plant cells is known as plant tissue culture.