A genetic preservation serves as an insurance policy for breeders and owners of valuable cattle by enabling them to extend and develop a specific bloodline when additional production is needed or untimely losses or reproductive inabilities occur.
2. introduction
• A genetic preservation is the first step in the cloning process,
allowing you to produce an identical genetic twin or clone,
which will be born at a later place in time.
• Gene preservation is an issue that we are seeing pop up with
strains a new wave of breeders and cultivators emerge ready
to profit off the industry.
• When preserved with tissue culture, genes are in a kind of
animated suspension and can be left in tissue banks can
protect gene lineages from pests, diseases, and other
challenges, without taking up excessive space.
• A genetic preservation serves as an insurance policy for
breeders and owners of valuable cattle by enabling them to
extend and develop a specific bloodline when additional
production is needed or untimely losses or reproductive
inabilities occur.
3. HISTORY
• In 1969, Galzy first report of successful in-vitro storage
of shoot tips of Vitis rupestris wherein at 9° C.
• In 1985, Steponkus cryopreservation at the temperature
of liquid nitrogen (-196°C) offers the possibility for
long-term storage with maximal phenotypic and
genotypic stability.
• In 1980, Withers relatively mature plant pieces can
provide basic information on interaction of freezing and
thawing rates, effects of ultra-low temperature on
storage of tissues and cold-hardening in relation to low
temperature tolerance.
4. types
• In-situ preservation – protecting areas of diversity, which is
generally ideal for wild relatives of crops
• Species with recalcitrant seeds
• Materials used include -
Isolated protoplasts
Cells from suspension or callus cultures
Meristem tips
• Merits
Primary /primitive
Inexpensive
Conserves all plant, animal and microbial communities in a habitat
Warranties the ecological processes, Evolution
Conservation of ecosystems , habitats
5. • Ex-situ preservation – done either in seed banks or field
collection
• In vitro conservation
• Seed gene banks –dried to low moisture content and stored at
low temperature .
• Field gene banks – plants are conserved in fields as living
collections as field plots, nurseries or green houses.
• Merits
Requires little space for maintaining large number of plants
Pest or pathogen free environment
Protection against dangers of environmental hazards
Protection against biotic and abiotic stresses
Genetic integrity
6. IN-VITRO CONSERVATION
• In-vitro system is extremely suitable for storage of plant material,
since in principle it can be stored on a small scale, disease free and
under conditions that limit growth.
• Germplasm storage in vitro is crucial for the future development
and safety of agriculture.
• Advantages
In vitro culture enables plant species that are in danger of being
extinct to be conserved.
In vitro storage of vegetative propagated plants can result in great
savings in storage space and time.
Sterile plants that cannot be reproduced generatively can be
maintained in vitro.
It is possible in vitro to efficiently reduce growth, which decreases
the number of subcultures necessary.
If a sterile culture is obtained, often with great difficulty, then
subculture in vitro is the only safe way of ensuring that it remains
sterile.
7. CRYOPRESERVATION
• Cryopreservation means “preservation in the frozen state”.
• E.g. over solid carbon dioxide (–79°C), in low temperature deep
freezers (–80°C or above), in vapor phase of nitrogen (–150°C).
• Generally the plant material is frozen and maintained at the
temperature of liquid nitrogen (–196°C).
• The cryopreservation of plant cell culture and seeds and eventual
regeneration of plants and it involves the following steps:
Raising sterile tissue cultures
Addition of cryoprotectants and pretreatment
Freezing
Storage
Thawing
Determination of survival/viability
Plant growth and regeneration
9. SLOW GROWTH METHOD
• Cells or tissues can be stored at non-freezing conditions
in a slow growth state rather than at the optimum level
of growth.
• Growing processes are reduced to a minimum by
limitation of a combination of factors like temperature,
nutrition medium, hormones, high osmotics etc.
• By this method, water in the tissue is maintained in the
liquid condition, but all biochemical processes are
delayed.
• All cultures in slow growth are static and therefore
require only shelf space in suitable environments.
10. Applications
• Conservation of genetic material: Large number of plant species
have been successfully maintained by means of cryopreservation
of cultured embryos, tissues, cells or protoplasts.
• Freeze storage of cell cultures: A cell line to be maintained has
to be sub cultured and transferred periodically and repeatedly over
an extended period of time. It also requires much space and
manpower. Freeze preservation is an ideal approach to suppress
cell division and to avoid the need for periodical sub-culturing.
• Maintenance of disease free stocks: Pathogen-free stocks of rare
plant materials could be frozen, revived and propagated when
needed. This method would be ideal for international exchange of
such materials.
• Cold acclimation and frost resistance: Tissue cultures would
provide a suitable material for selection of cold resistant mutant
cell lines, which could later differentiate into frost resistant plants.
11. LIMITATION
• Greater skill in handling and maintenance of cultures is
required.
• Sophisticated facilities are required.
• Plants may show genetic instability.
• Cell/tissues get damaged during cryopreservation.
• Cryopreservation procedures are genotype dependent.
• Cost of maintenance of large collection is very high.
• Slow growth cultures are vulnerable to contamination.