1. Callus culture involves growing undifferentiated plant cells and tissues on a nutrient medium under sterile conditions. This allows for the production of genetically identical clones without seeds or pollination. 2. A callus is an unorganized mass of cells formed from injured or cultured plant tissue. Successful callus culture requires selecting an explant, preparing sterile culture media, and regulating hormone levels to induce cell proliferation. 3. Callus cultures are maintained through periodic sub-culturing to replenish nutrients and prevent toxicity. The growth and characteristics of callus tissue can provide insights into plant cell metabolism, differentiation, and pathways for genetic engineering applications.

1. Callus Culture in Plants
DR. DIVYA SHARMA
ASSISTANT PROFESSOR
A Biodiction (A Unit of Dr. Divya Sharma)

2. Plant Tissue Culture
 Plant Tissue Culture ----- A collection of experimental methods of growing plant cells,
tissues and organs in an artificially prepared nutrient medium static or liquid, under aseptic
conditions
 Also referred to as Micropropagation
 G. Haberlandt was firstly introduced about Plant tissue culture
 The basic key used in plant tissue culture is the totipotency of plant cells, meaning that each
plant cell has the potential to regenerate into a complete plant
 With this characteristics, plant tissue culture is used to produce genetically identical plants
(clones) in the absence of fertilization, pollination or seeds

3. Callus Culture
Callus --------- Undifferentiated mass of cell
 Formed by the proliferation of the parent tissue
 Cells are parenchymatous, amorphous and unorganized. Callus is formed as a result of injury
at the cut ends of a stem or a root
 When tissue on culture produce unorganized mass of callus with no regular form, called Callus
Culture
 Rechinger, 1893 was firstly observed
 Production and maintenance of callus on a solidified nutrient medium under aseptic
conditions

4. Steps of Callus Culture
1. Selection and collection of explant material
2. Selection and preparation of culture media
3. Surface sterilization of explant material
4. Preparation of explant
5. Inoculation (transfer) of explant in culture medium
6. Incubation of culture
7. Sub-culturing of culture
8. Regeneration of plant from callus (Organogenesis and Embryogenesis method)

5. Explant Materials
 Callus may initiate from explants of any multicellular plant
 Explant from stem, root, leaf, flower, fruit or seed etc. may be taken for culture
 Examples of Callus formation are :
Storage parenchyma, pericyclic cells of roots, cambial cells of vascular bundles, perivascular
cells, secondary phloem, pith cells, mesophyll cells and cotyledons

6. Reason of Sub-culturing Callus
CallusCulture
Nutrient
may be
exhausted
CallusCulture
Agar may
be
desiccated
CallusCulture
Cell
metabolites
may
accumulate
and cause
toxicity

7. Callus Culture Medium
Standard media ------------ Murashige and Skoog’s medium
 Kinetin used for initiation and maintaining callus
 Usually required an exogenous supply of hormone for initiation of callus
 According to hormone requirement callus culture are:
 Auxin
 Cytokinins
 Cultures required both Auxin and Cytokinin
 Gibberellin

8. Monitoring of Callus Growth
Fresh weight measurement
(most convenient)
Dry weight measurement
(most accurate)
Mitotic index measurement
(for cell divisional rate)

9. Carrot Root Culture

10. Stages of Callus Culture Development
Callus formation from an explants occur in three stages:
A. Induction stage:
Metabolism is stimulated and the cells prepare to divide. Cell size remains unchanged
B. Cell division stage
Cells divide actively and the cell size decreases. Cell division is mainly periclinal and occurs
towards the periphery giving rise to wound cambial cells

11. Callus Culture Development
C. Differentiation stage:
 Cells differentiate by expansion and maturation
 Rapidly growing the calluses are more or less alike but as the growth rate decrease the
calluses show their characteristic structures and forms
 But all calluses have some similarities
 Contain nodular or sheet meristems in group or scattered throughout the tissue

12. Nature of Callus Tissue
 Some cultures are hard, consists of compactly arranged small cells without intercellular
spaces, composed of lignified cells
 Other callus friable consists of large loosely arranged cells with intercellular spaces
 Friable callus is fragile and easily breaks up
 These are suitable for suspension culture, where the tissue can be dispersed by mechanical
agitation
 The color of the callus also varies and usually depends on the color of the tissue from which it
is taken
 The callus maybe colorless or green containing chlorophyll or yellow carotenoids or flavonoids
or it maybe purple due to the presence of anthocyanin
 Callus may be uniformly or partially colored

13. Significance of Callus Culture
 Determine the total amount of nucleic acids (DNA and RNA) rapidly from callus culture
 By using tracer elements in callus culture the path of various metabolic processes has been
determined
 Friable callus is suitable for cell suspension culture

14. Thank you
A Biodiction (A Unit of Dr. Divya Sharma)