what is callus culture
Callus culture is a plant tissue culture technique in which a small piece of plant tissue (an explant) is grown on a nutrient medium under sterile, in‑vitro conditions so that it forms an unorganized, undifferentiated mass of cells called callus.
What is callus?
- Callus is a mass of cells that have lost their normal structure and function (no organized roots, stems, xylem, etc.).
- These cells are usually parenchymatous, soft and amorphous but still alive and actively dividing.
- They are often described as “plant stem‑cell–like” because they can later be induced to form whole organs or even complete plants.
Definition of callus culture
- Callus culture is the in‑vitro cultivation of callus tissue on an artificial, sterile nutrient medium, usually containing mineral salts, vitamins, sugar and plant growth regulators (auxin and often cytokinin).
- The explant (leaf piece, stem, root, seed, etc.) is placed on this medium, where the hormone balance triggers dedifferentiation (loss of specialized structure) and proliferation into callus.
Key steps (quick view)
- Selection of explant (e.g., carrot slice, leaf segment, stem node).
- Surface sterilization to remove microorganisms.
- Placement (inoculation) of the explant onto a solid nutrient medium with an appropriate auxin/cytokinin balance.
- Incubation under controlled temperature, light and humidity until callus appears and grows.
- Periodic subculture onto fresh medium to maintain growth and prevent nutrient depletion or toxicity.
Why is callus culture important?
- Clonal propagation: Produces many genetically identical plants from a small amount of starting material.
- Plant breeding and genetic engineering: Provides a convenient target tissue for transformation and selection of new traits.
- Secondary metabolite production: Callus can be used like a “cell factory” to produce valuable plant chemicals (e.g., medicinal compounds) in controlled conditions.
- Basic research: Helps scientists study plant cell division, differentiation and responses to hormones and stress.
Mini comparison: callus vs other plant cultures
| Type | What is grown? | Main feature |
|---|---|---|
| Callus culture | Undifferentiated cell mass from explants | Unorganized, totipotent tissue, can regenerate whole plants. | [3][5][7]
| Organ culture | Whole organs (root, stem, shoot) | Preserves original structure to study growth and function. | [3]
| Meristem culture | Growing tips (meristems) | Fast, disease‑free cloning of plants. | [3]
| Protoplast culture | Cells without cell walls | Useful for cell fusion and advanced genetic manipulation. | [3]
In simple exam‑style wording
Callus culture is the in‑vitro culture of plant explants on a nutrient medium containing suitable plant growth regulators, leading to the formation and maintenance of an unorganized, proliferating mass of undifferentiated cells called callus, which can later be induced to regenerate whole plants.
Information gathered from public forums or data available on the internet and portrayed here.