2. The culture of plant seeds, organs, tissues,
cells, or protoplasts on nutrient media under
sterile conditions.
3. Two Hormones Affect Plant Differentiation:
◦ Auxin: Stimulates Root Development
◦ Cytokinin: 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
5. In vitro Clonal Propagation.
Micropropagation is the practice of rapidly
multiplying stock plant material to produce a
large number of progeny plants, using modern
plant tissue culture methods.
6. Clone is a plant population derived from a
single individual by asexual reproduction.
Clonal Propagation is the multiplication of
genetically identical individuals by asexual
reproduction.
7. Clonal reproduction
Multiplication stage can be recycled many
times to produce an unlimited number of
clones
Easy to manipulate production cycles
Disease-free plants can be produced
8. Rapid clonal in vitro propagation of plants:
• From cells, tissues or organs
• Cultured aseptically on defined media
• Contained in culture vessels
• Maintained under controlled conditions of
light and temperature
15. Stage I –Establishment
◦ Selection of the explant plant
◦ Sterilization of the plant tissue takes place
◦ Establishment to growth medium
Stage II - Proliferation
◦ Transfer to proliferation media
◦ Shoots can be constantly divided
Stage III – Rooting & Hardening
◦ explant transferred to root media
◦ explant returned to soil
16. Organogenesis
◦ Organogenesis via callus formation
◦ Direct adventitious organ formation
Embryogenesis
◦ Direct embryogenesis
◦ Indirect embryogenesis
Microcutting
◦ Meristem culture (Mericloning)
◦ Bud culture
17. PGRs are prob. the most important factor affecting
organogenesis
◦ cytokinins tend to stimulate formation of shoots
◦ auxins tend to stimulate formation of roots
The central dogma of organogenesis:
◦ a high cytokinin:auxin ratio promotes shoots and
inhibits roots
◦ a high auxin:cytokinin ratio promotes roots and/or
callus formation while inhibiting shoot formation
18. The process of initiation and development of a
structure that shows natural organ form and
function.
The ability of non-meristematic plant tissues to
form various organs de novo.
The production of roots, shoots or leaves.
These organs may arise out of pre-existing
meristems or out of differentiated cells.
This, like embryogenesis, may involve a callus
intermediate but often occurs without callus.
19. Tissue culture maintains the genetic of the cell
or tissue used as an explant.
Tissue culture conditions can be modified to
cause to somatic cells to reprogram into a
bipolar structure.
These bipolar structures behave like a true
embryo - called somatic embryos.
20. An Embryo is made up of actively growing
cells and the term is normally used to describe
the early formation of tissue in the first stages
of growth.
21. The process of initiation and development of
embryos or embryo-like structures from
somatic cells
The production of embryos from somatic or
“non-germ” cells.
Usually involves a callus intermediate stage
which can result in variation among seedlings
22. Somatic embryogenesis is a useful
regeneration pathway for many monocots and
dicots, but is especially useful for the grasses
Types of embryogenesis
◦ zygotic embryogenesis – the result of normal
pollination and fertilization
◦ somatic embryogenesis – embryos from
(cultured) sporophytic cells , that is embryos
arise indirectly
23. The composition of the culture medium
controls the process-
◦ auxin (usually 2,4-D) added causes
induction, the formation of embrygogenic
clumps or proembryogenic masses (PEMs)
(induction medium)
◦ auxin is deleted and the clumps become
mature embryos (maturation medium)
24. Stages of development
◦ early cell division doesn't follow a fixed
pattern, unlike with zygotic embryogenesis
◦ later stages are very similar to zygotic
embryos (dicot pattern)
globular stage (multicellular)
heart-shaped stage (bilateral symmetry) –
bipolarity
torpedo-shaped stage – consists of initial
cells for the shoot/root meristem
25.
26. Somatic Embryogenesis
Stimulation of callus or suspension cells to undergo a
developmental pathway that mimics the development of the
zygotic embryo.
27. • From one to many propagules rapidly.
• Multiplication in controlled lab conditions.
• Continuous propagation year round.
• Potential for disease-free propagules.
• Inexpensive per plant once established.
28. • Specialized equipment/facilities required.
• More technical expertise required.
• Protocols not optimized for all species.
• Plants produced may not fit industry
standards.
• Relatively expensive to set up.
29. • Equipment/facility intensive operation
• Technical expertise in management positions
• Protocols not optimized for all species
• Liners may not fit industry standard
• Propagules may be too expensive
30. • Rapid increase of stock of new varieties.
• Elimination of diseases.
• Cloning of plant types not easily propagated
by conventional methods.
• Propagules have enhanced growth features
(multibranched character;Ficus, Syngonium)
