FAQs on Plant Tissue culture

What is Plant Tissue Culture?

It is the process of producing plants from tissues of the desired plant in an artificial nutrient medium under controlled environment. The plants so produced would be exactly similar to the mother plant in all aspects.

What is totipotency?

Totipotency is a characteristic feature of a plant cell which signifies that a single cell is capable of giving rise to the whole plant i.e. the cell has the inherited capacity of differentiation and dedifferentiation. The term was first coined by Habertland in 1902.

How plant tissue culture/ micro propagation is done ?

A small piece of plant tissue (explant) is taken fr om the donor plant and cultured on a nutrient medium in sterile containers. By altering the composition of the medium and the environmental conditions (temperature, light regime, etc.) the development of this piece of tissue can be directed along different patterns and finally the whole plant can be regenerated. The offspring comes from a single plant and are thus identical to each other and to the mother plant.

Why one should go for tissue culture plants?

Tissue culture plants are qualitatively better as they are produced under aseptic condition and controlled environment. One should go for tissue culture plants for the following reasons.

• Tissue culture raised plants are vigorous and fast growing than conventional plants.
• High degree of uniformity than the conventionally produced plants.
• The tissue culture plantlets are free from diseases/pathogens.
• It is possible to multiply plants that are difficult to propagate by cuttings or other traditional methods.
• Tissue culture plants yield better as they are produced under optimum environment from selected mother plants.

What is an explant? What are the types of explants used in Plant Tissue Culture?

An explant is the part of a plant which has got the regeneration potential and is capable to give rise to the whole plant. There are various types of explants frequently used for regeneration purpose: nodal segments, apical meristems, roots, cotyledons, embryo, leaf disc, leaf blade, pedicle, petiole, anther, ovary etc.

What are the crops being propagated by Plant Tissue Culture commercially?

Banana, Sugarcane, Potato, Bamboo, Ginger, Apple, Black Pepper, Citrus, Vanilla, Anthurium, Teak, Strawberry, Lillium, Cardamom, Mangium, Gerbera, Fig, Jatropha, Carnation, Grape, Turmeric, Orchids etc. are comely used for large scale production for domestic as well as export market.

Whether tissue culture plants are more prone to pest and diseases than plants propagated conventionally?

The tissue culture raised plants are free from disease and pest, if the standard procedures are adopted for production. Tissue culture plants grow faster and better, yet they are as vulnerable as any other plants unless appropriate precautions are taken. However, tissue culture plants are free from soil borne diseases.

Do tissue culture plants yield better than the conventional plants?

As tissue culture plants are uniform, vigorous and disease free, if proper cultivation practices are properly followed, the total yield is expected to be better compared to conventional plants.

What is a mother plant?

Mother plant is the source of explants to be used for further multiplication. (*Note: That the mother plant should be devoid of any bacterial/fungal infections before using for multiplication).

What are the constituents of plant tissue culture nutrient media?

The components of plant tissue culture nutrient media are: Water, Inorganic salts, Plant growth regulators, Vitamins, Amino acids, Carbon sources and Solidifying agents (in case of a solid medium).

How do plant growth regulators affect plant morphogenesis in culture?

Two plant growth regulators affect plant differentiation:
Auxins: Stimulate root development
Cytokinins: Stimulates shoot development
Generally, the ratio of these two hormones can determine plant development:
Auxin> cytokinin = Root development
Cytokinin> auxin = Shoot development
Auxin = Cytokinin = Callus development

What is organogenesis?

Organogenesis: The process of initiation and development of a structure that shows natural organ form and/or function.

What is embryogenesis?

Embryogenesis: The process of initiation and development of embryos or embryo-like structures from somatic cells (somatic embryogenesis).

What is the embryo rescue technique?

It is an in vitro technique in which the embryo (resulting from a wide hybridization where fertilization occurred, but embryo development did not occur) is cultured. Its merits are:

• Rescues F1 hybrid from a wide cross.
• Overcomes seed dormancy, usually with addition of hormone to media (GA).
• Overcomes immaturity in the seed.
• To speed generations in a breeding programme.
• To rescue a cross or self (valuable genotype) from a dead or dying plan

What are the various stages of micropropagation?

Stage 0 – Selection and preparation of the mother plant
Sterilization of the plant tissue takes place
Stage I - Initiation of culture
Explant placed into growth media
Stage II - Multiplication
Explant transferred to shoot media; shoots can be constantly divided
Stage III - Rooting
Explant transferred to root media
Stage IV - Transfer to soil
Explant returned to soil; hardened off

What is an artificial seed?

Artificial seeds are formed by encapsulating the somatic embryos in 0.2% solution of sodium alginate, this solution forms a gel at later stages and acts as seed coat, such type of somatic embryos are called artificial seeds. Such embryos (artificial seeds) are genetically identical and can be stored for long durations before use.

What is photoautotrophic micropropagation?

Photoautotrophic micropropagation is a phenomena in which a plant is grown under in vitro environment without the addition of carbon source in the medium. This allows autotrophic growth (increased photosynthetic efficiency) of the plant which has the advantage of better acclimatization under ex vitro condition than conventional methods.

What are the in vitro parameters affecting plant growth?

The in vitro parameters affecting plant growth are: photoperiods (light and dark cycles), temperature, carbon source, plant growth regulators, macro and micro nutrients, vitamins, water etc.

What are the parameters affecting ex vitro growth of plants?

Parameters affecting ex vitro growth of plants are: temperature, light (quality/quantity), relative humidity, soil characteristic, soil nature etc. These biotic and abiotic factors in combination are responsible for overall growth and development of plant.

Source : National Certification System for Tissue Culture Raised Plants (NCS-TCP)

Related resources

1. Standard Operating Procedures for Tissue Culture Production Facility
2. Plant Tissue Culture : Techno-Commercial Feasibility
3. Crop specific tissue culture standards