This presentation include basic Micropropagation protocol: Application and advantages of mass multiplication. Beside this the requirement of tissue culture are there (Nutrient, gelling agent, energy source, vitamins and PGRs) are also included.
Analytical Profile of Coleus Forskohlii | Forskolin .pptx
Mass multiplication procedure for tissue culture and PTC requirement
1.
2. INTRODUCTION
Tissue culture is the in vitro aseptic culture of cells,
tissues, organs or whole plant under controlled
nutritional and environmental conditions often to
produce the clones of plants.
The resultant clones are true-to type of the selected
genotype.
The controlled conditions provide the culture an
environment conducive for their growth and
multiplication. These conditions include proper supply
of nutrients, pH medium, adequate temperature and
proper gaseous and liquid environment.
3. MASS MULTIPLICATION
Plant tissue culture technology is being widely used for large scale
plant multiplication.
Apart from their use as a tool of research, plant tissue culture
techniques have in recent years, become of major industrial
importance in the area of plant propagation, disease elimination,
plant improvement and production of secondary metabolites.
Small pieces of tissue (named explants) can be used to produce
hundreds and thousands of plants in a continuous process. A single
explants can be multiplied into several thousand plants in relatively
short time period and space under controlled conditions, irrespective
of the season and weather on a year round basis.
Endangered, threatened and rare species have successfully been
grown and conserved by micropropagation because of high
coefficient of multiplication and small demands on number of initial
plants and space.
4. STAGES IN THE DEVELOPMENT OF TISSUE CULTURE
PROCESS FOR MASS MULTIPLICATION
Selection of superior clone
Collection of young branches and shoots
Introduction of Explants for in vitro culture
Shoot development from responsive explants
Elongation and Rooting stage
Multiplication of plantlet
6. WHAT CONDITIONS DO PLANT CELLS NEED
TO MULTIPLY IN VITRO?
Tissue culture has several critical requirements:
Optimal protocol for mass multiplication
Appropriate tissue (Explant)
A suitable growth medium containing energy sources and
inorganic salts to supply cell growth needs. This can be
liquid or semisolid.
Aseptic (sterile) conditions, as microorganisms grow much
more quickly than plant and animal tissue and can over run
a culture.
Growth regulators - both auxins & cytokinins.
Frequent subculturing to ensure adequate nutrition and to
avoid the build-up of waste metabolites.
7. APPROPRIATE TISSUE (EXPLANT)
Cell, tissue or organ of a plant that is used to start in
vitro cultures. Many different explants can be used for
tissue culture, but auxillary buds and meristems are
most commonly used.
The explants must be sterilized to remove microbial
contaminants. This is usually done by chemical surface
sterilization of the explants with an agent such as
bleach at a concentration and for a duration that will
kill or remove pathogens without injuring the plant cells
beyond recovery.
8. After tissue injury during dissection, such compounds will
be oxidized by polyphenol oxidases →tissue turn
brown/black.
Phenolic products inhibit enzyme activities and may kill
the explants
Methods to overcome browning:
o Adding antioxidants [ascorbic acid, citric acid, PVP
(polyvinylpyrrolidone), dithiothreitol], activated charcoal
or presoaking explants in antioxidant
o Incubating the initial period of culturing in reduced
light/darkness
o Frequently transfer into fresh medium
9. NUTRITION MEDIUM
When an explants is isolated, it is no longer able to receive
nutrients or hormones from the plant, and these must be
provided to allow growth in vitro.
In addition, the culture must be provided with the ability to
excrete the waste products of cell metabolism. This is
accomplished by culturing on or in a defined culture medium
which is periodically replenished.
A nutrient medium is defined by its mineral salt composition,
carbon source, vitamins, plant growth regulators and other
organic supplements.
pH determines many important aspects of the structure and
activity of biological macromolecules. Optimum pH of 5.0-6.0
tends to fall during autoclaving and growth.
11. MINERAL SALT COMPOSITION
Macroelements: The elements required in concentration
> 0.5 mmol/l
The essential macroelements: N, K, P, Ca, S, Mg, Cl
Microelements: The elements required in conc. < 0.5
mmol/l
The essential microelements: Fe, Mn, B, Cu, Zn, I, Mo, Co
The optimum concentration →maximum growth rate
12. CARBON SOURCES AND VITAMINS
Sucrose or glucose (sometimes fructose), concentration
2-5% (20-40 g/l usually)
An absolute requirement for vitamin B1 (thiamine)
Growth is also improved by the addition of nicotinic
acid and vitamin B6 (pyridoxine)
Some media contain pantothenic acid, biotin, folic acid,
p-amino benzoic acid, choline chloride, riboflavine and
ascorbic acid (C-vitamin)
14. OTHERS
Media formulations
Natural complexes (undefined)
Gelling agent and supporting system
Charcol
Oraganic acid
Antibiotics
Amino acid / organic salts
15. CELLULAR TOTIPOTENCY AND PLANT REGENERATION
Unlike an animal cell, a plant cell, even one that highly
maturated and differentiated, retains the ability to
change a meristematic state and differentiate into a
whole plant if it has retained an intact membrane
system and a viable nucleus.
Totipotency or Totipotent: The capacity of a cell (or a
group of cells) to give rise to an entire organism.
Cultured tissue contain competent cells or cells capable
of regaining competence (dedifferentiation). e.g. an
excised piece of differentiated tissue or organ
Dedifferentiation →callus
Redifferentiation (whole plant) = cellular totipotency.
16. 1957 Skoog and Miller demonstrated that two
hormones affect explants’ 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
17. CLONAL PROPAGATION/MICROPRAPAGATION
“… the art and science of multiplying plants in vitro.”
Commercial production of plants through micropropagation
techniques has several advantages over the traditional
methods of propagation through seed, cutting, grafting and
air-layering etc. It is rapid propagation processes that can
lead to the production of plants virus free.
The success of many in vitro selection and genetic
maniplation techniques in higher plants depends on the
success of in vitro plant regeneration.
A large number of plants can be produced (cloned) starting
from a single individual
18. Micropropagation allows the production of large
numbers of plants from small pieces of the stock
plant in relatively short periods of time. Depending on
the species in question, the original tissue piece may
be taken from shoot tip, leaf, lateral bud, stem or
root tissue.
It is vegetative (asexual) methods of propagation which
can be used to produce 1,000,000 propagules in 6
months from a single plant.
20. STAGES IN MICROPROPAGATION
Micropropagation starts with the selection of plant
tissues (explants) from a healthy, vigorous mother plant.
Any part of the plant (leaf, apical meristem, bud and
root) can be used as explants.
Stage 0: Preparation of donor plant :
Any plant tissue can be introduced in vitro. To enhance
the probability of success, the mother plant should be
ex vitro cultivated under optimal conditions to minimize
contamination in the in vitro culture
21. Stage I: Initiation stage
In this stage an explant is surface sterilized and transferred
into nutrient medium.
Generally, the combined application of bactericide and
fungicide products is suggested. The selection of products
depends on the type of explants to be introduced.
The surface sterilization of explant in chemical solutions is
an important step to remove contaminants with minimal
damage to plant cells. The most commonly used
disinfectants are sodium hypochlorite, calcium hypochlorite,
ethanol and mercuric chloride (HgCl2).
The cultures are incubated in growth chamber either under
light or dark conditions according to the method of
propagation.
22. Stage II: Multiplication stage
The aim of this phase is to increase the number of
propagules [22]. The number of propagules is multiplied by
repeated subcultures until the desired (or planned) number
of plants is attained.
Stage III: Rooting stage
The rooting stage may occur simultaneously in the same
culture media used for multiplication of the explants.
However, in some cases it is necessary to change media,
including nutritional modification and growth regulator
composition to induce rooting and the development of
strong root growth.
23. Stage IV: Acclimatization Stage
At this stage, the in vitro plants are weaned and
hardened. Hardening is done gradually from high to
low humidity and from low light intensity to high
light intensity.
The plants are then transferred to an appropriate
substrate (sand, peat, compost etc.) and gradually
hardened under greenhouse.
24. APPLICATIONS OF MICROPROPAGATION
Screening cells rather than plants for advantageous
characters, e.g. herbicide resistance/tolerance.
Large-scale growth of plant cells in liquid culture
To cross distantly related species by protoplast fusion
and regeneration of the novel hybrid.
Embryo rescue
For production of doubled monoploid plants from
haploid cultures to achieve homozygous lines
As a tissue for transformation, followed by either short-term
testing of genetic constructs or regeneration of
transgenic plants.
In vitro conservation of germplasm
25. ADVANTAGES OF MICROPROPAGATION
Micropropagation offers several distinct advantages not
possible with conventional propagation techniques.
i. Rapid multiplication of genetically uniform plants
ii. The production of multiples of plants in the absence of
seeds or necessary pollinators to produce seeds
iii. The regeneration of whole plants from plant cells that have
been genetically modified.
iv. The production of plants in sterile containers that allows
them to be moved with greatly reduced chances of transmitting
diseases, pests and pathogens.
v. The production of plants from seeds that otherwisehave
very low chances of germinating and growing, e.g. orchids
and nepenthes.
vi. The production of plants throughout the year i.e. not affected
by environmental conditions.
27. REFERENCE
Akin-Idowu, P. E., Ibitoye D.O. and Ademoyegun, O.T. (2009).
Tissue culture as a plant production technique for horticultural
crops. Afr. J. Biotechnol. 8(16): 3782-3788.
George, E.F. (1993). Plant propagation by Tissue Culture. Eastern
Press, Eversley.
Hussain, A., Ahmed, I., Nazir, H., and Ullah, i., (2012). Plant
Tissue Culture: Current Status and Opportunities.
http://dx.doi.org/10.5772/50568
Modi, A. R., Patil, G., Kumar, N., Singh, A. S., Subhash, N., (2012).
A Simple and Efficient In Vitro Mass Multiplication Procedure for
Stevia rebaudianaBertoni and Analysis of Genetic Fidelity of In
Vitro Raised Plants Through RAPD. Sugar Tech (Oct-Dec 2012)
14(4):391–397
Chaturvedi, H.C., Jain, M. and Kidwai, N. R. (2007). Cloning of
medicinal plants through tissue culture - A review. Indian
journal of experimental biology, 45: 937-948.