Transcript Biotechnological application in Conservation

Biotechnological
Application in Conservation
Prof. (Dr. ) S.C.Santra
Dept. of Environmental Science
University of Kalyani, Nadia,
West Bengal
Modern biotechnology began with the
first recombinant DNA experiment in
1973. But its real application started
after 1980, when the U.S. Supreme
Court held that a genetically engineered
microorganism was patentable, then
biotechnological companies formed to
commercialize
recombinant
DNA
technology.
• In recent decades, a multicentric project on bioprospecting of
biological wealth using biotechnological tools has been launched in
various countries. The overall objective is of characterization,
inventorization and conservation of biodiversity of different
ecogeographical regions and prospecting of nenes and biomecules.
• Economically and medicinally important species are being prospected
for genes and bioactive molecules of therapeutic and agricultural
importance, conservation strategies are being worked out depending
on the species richness.
• Economically important elite varieties have been identifical and the
fingerprinting is being done to compare accession/collection from
different geographical locations.
• This is helping in developing conservation strategies, especially for the
endangered species. Geneprospecting studies have also been
successful and today nearly 25 stress tolerant genes from identified,
characterized and cloned. Studies are also ongoing for transfersing
these genes to other economically important crop plants.
Biotechnology in ex-situ
conservation
Ex-situ (away from the habitats or sites) conservation
method of Biodiversity and Wild life Protection is seldom
sufficient process. Almost any species could be preserved
ex-situ if enough money were devoted to it, but in practice it
is usually high quality species or races, such as relatives of
crops, domestic animals and charismatic species which are
protected in this way. In general ex-situ methods have
proved a very valuable complement to in-situ methods and
a number of species would not have survived without the
synergy between the two.
Collection of species and races for ex-situ
conservation has now become a race against time
and a range of methods have been developed to
collect pure strains, avoid hybridization, and
minimize impacts on wild populations.
There are a number of ex-situ conservation practices
as adopted over the time mentioned as follows:
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Gene bank (DNA bank)
Seed banks,
Tissue culture bank,
Seedling banks.
Conservation strands,
Cryopreservation of ova, sperm or embryo
Advantages and disadvantages of ex-situ conservation methods
Conservation strategy
Advantages
Disadvantages

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Propagules readily available for use,
Minimum work, little space is
required,
Provenance (clinical, geographical)
variation can be conserved provided
species range adequately sampled.
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Minimum space required
Applicable for plants with
recalcitrant or orthodox seed
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Minimum space required
Genetic erosion reduced
Short time required to produce
propagules
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Minimum space is required,
Species with high extinction
potential can be conserved,
Applicable to all kinds of plants &
animals,
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Minimum space is required,
All kinds of plants/animals
components can be preserved
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Seed Banks:
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Pollen Banks:
Tissue Culture
Banks:
DNA Banks or Gene
Banks:
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Cryopreservation of
ovum, sperm or
embryo
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Recalcitrant seed can not be
conserved,
Large seed preservation is
problematic
Dose not conserve associated
species.
Only half of the genome
conserved,
Tricellular pollen storage is
problematic
Sometime sampling is
problematic
Problem some clonal variation
Very costly to maintain the
system
Not a easy method, which
required skilled persons.
Involves freezing, with liquid
nitrogen, very costly method
Viability of healthy clone is
sometime questionable
Ex-situ conservation technology
Sl. No. Methods
Purpose
Examples
1.
Embryo micropropogation
Increasing population Orchids and many
other plants
2.
Somatic embryogenesis
Do
Bamboo, cycads and
others
3.
Clonal propagation of shoot tips
Do
Ornamental plants,
4.
Artificial insemination
Do
Tiger, Giant Panda
5.
Embryo axis cryopreservation
Storage of recal
eitrant species
Quereus sp. (Oak)
6.
Cryopreservation of cell suspession
Do
Orchids
7.
Storage of seeds in moist substrate
Breaking dormancy
Several plant species
8.
Cryopreservation of sperm, ovum,
embryo of animals
Storage of germ
plasm
Several wild animals
9.
Seed storage at low temperature
(-21°C)
Imposing dormancy
Several crop seeds
Preservation of plants or seed in genebanks
or in vitro cell lines or cloned in tissue
collections under appropriate conditions or
longterm storage often seems to be the
easiest and most preferred mode. Genebank
collections and in fact many breeders
collections are too large for scientist to
intensively investigate and record all traits in
the sereening process.
Net work of Gene banks of some crops
Sl. No.
Crops
Locations
01
Rice -
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Oryza sativa
oryza indica
Wild rice species
IRRI , Philippines
IRRI , Philippines
IRRI , Philippines
02
Wheat -
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Cultivated species
VIR Russia
CNR, Italy
03
Maize -
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New World materials
Asiatic materials
CIMMYT, Mexico
NSSL, USA
04
Millets -
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Cultivated &
Wild species
Minor Millets
ICRISAI, India
NSSL, USA
ICAR, India
05
Oats -
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Cultivated & wild Species
PGR, Cnada
06
Sugarcane -
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Cultivated
ICAR, India
NPGS, USA
07
Potato -
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Wild & cultivated species
CIP, Peru
AVRDC, Taiwan
08
Groundnut -
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Cultivated species
ICRISAT, India
09
Soabean -
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Cultivated species
CIAT, USA
10
Phaseolus -
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Cultivated species
German Seed bank
Threats to Germplasm of crop plants & its conservation need
A technological fact of improved varieties is that they have a tendency to
eliminate the resource that they are based on and from which they have been
derived by breeding. Current elite varieties yield better than the varieties they
displace, and once a displaced variety is no longer planted, its genes are lost to
future generations unless it is conserved. The gene rich ancestral forms are lost
because
of
bad
land
use
planning,
environmental
degradation
and
urbanization. The wholesale loss of plant genetic resources is called genetic
erosion. It is a slow and gradual process.
In the developing world, high yielding varieties (HYV) for the major crop have
come into dominance just within the past three – four decades. The traditional
local germplasm is wiped out and genetic vulnerability could be seed as
consequent events. Thus germplasm conservation became a top priority today
in agriculture.
A better understanding of gene banks requires an
appreciation of the kinds of genetic materials that can be
saved as seed. Germplasm can be organized into five distinct
categories.
•
Varieties of cultivars in current use, often elite varieties;
•
Obsolete cultivars, Often the elite varieties of 20 to 50
years ago and usually formed in the parcentage of
current cultivers;
•
Primitive cultivers
agricultures,
•
Wild and weedy taxa, near relatives of crop plants,
•
Special genetic stocks, including induced mutants.
and
landraces
of
traditional
Inbreeding depression of wildlife and need for germplasm
conservation
Inbreeding depression is a decline in viability and /or fecundity of
indiriduals resulting from mating between close relatives. Inbreeding
is minimized in an idealized population, in which individuals mate
randomly. However populations may depact from this giving a low
genetic variations. If deleterious recessive alleles become
homozygons, pathological conditions result. Wild populations are
seldom sufficiently well known to withness inbreed depression and
this showed high rate of, mortality in their natural habitats.
Germplasm conservation of such population is highly essential.
Some examples of the consequence of inbreeding depression of wild
animals
Sl.
No.
Animals
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Consequences
01
Cheetah (Captive population)
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Low sperm concentration high
vulnerability to infection;
02
Florida panther
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Low sperm quality vulnerable to
microbial parasites
03
Siberian tiger (Captive population)
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Decreased fertility & viability to zoo
04
Golden lion tamarin
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Increased juvenile mortality
05
Common shrend
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Decreased fertility
06
Song sparrow
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Reduced survibility
Thus use of biotechnology tools is conservation
practices are very much essential today, through
there are some adverse impacts of biotechnology on
biodiversity specially with respect to non-target
effects
of GMO in natural ecosystem. Raises the
questions of biosafety issues and also disstatrilization
of dynamicity of natural ecosystem.
Thank You