Significance of wild relatives of cultivated plants and domesticated animals
Domestication is the process by which
Plants, animals and microbes are selected from the wild and adapted to habitats
created by humans. It is also termed as
cultivation in the case of plants and microbes.
Modern livestock breeds and crop species are
bred to be highly productive. Chickens have been bred to maintain a uniform
size for cost effective production, while fruit and vegetables have been bred
to have thick, juicy flesh. To achieve these desirable characteristics, plants
and animals are bred with ever more genetically similar partners, leaving a narrow
and homogeneous gene pool that make their species sensitive to diseases and
environmental changes.
Wild relatives of domesticated plants and
animals are the ancestral species from which crops and livestock have
descended, or their near relatives. The pigs that are raised for food are
descended from wild boar (Sus scrofa)
and chickens are descended from red jungle fowl (Gallus gallus). These wild species are sufficiently closely related
to domestic varieties so that they could crossbreed to increase the genetic
diversity in the domesticated species.
The wild relatives of domesticated species
inhabit the wild areas of nature, the rocky and icebound high mountain ranges,
dense tropical forests and deserts. Genetic diversity helps species survive
into the future. They continued to evolve under natural conditions and might
contain genes that will help them to fight diseases and remain productive in a
changing environment.
As climate changes are resulting in some
growing regions hotter and drier, wild relatives of corn that are
drought-resistant could be crossbred with farmed varieties to make them more resilent.
As new pathogens emerge, wild relatives of cows could crossbreed with cattle to
reinforce their immune defense.
Few of the ancestral species and wild
relatives are common as jungle fowl or wild boar. But wild relatives of a large
number of domesticated plants and animals are either unknown or highly
threatened or even on the verge of extinction. Baer’s pochard (Aythya baeri) is
a critically endangered duck species that is closely related to the domestic
duck. The Kouprey (Bos sauveli) is a wild relative of the cow and may even be
extinct in the wild.
We, humans rely on very few species for
food and use commercially-bred livestock and crops and are gradually losing the
wild relatives (the reservoir of genetic diversity). The threat of climate
change makes these genetic resources increasingly important for surviving the
knock-on effects of climate change on agriculture.
Protecting wild relatives of plants
Crop wild relatives or CWR are wild plant
species genetically related to cultivated crops. They are untended by humans
and continue to evolve in the wild. They are a fantastic source of plant
genetic diversity and are continually developing traits such as drought
tolerance or pest resistance and they can be of use to farmers and breeders to
cross with domesticated crops to produce new varieties.
CWR occur in a wide range of habitats but
are at great risk as habitats are being degraded and lost worldwide. The key to
successful crop improvement is the continued supply of genetic variability and
beneficial traits contained in this diversity.
The wild relatives of modern crops are the source of diversity,
providing genes with improved nutritional quality, resistance to pests and
diseases, drought and extreme temperatures.
The plant genetic resources (PGR) can be
conserved as stored collected material ex situ in gene banks or through in situ
approaches. The in situ conservation allows populations to continue to evolve
and generate new variation in their habitat, but it is a complex and
multidisciplinary process
The Importance of Crop Wild Relatives
·
They are a source of resistance against
pests and diseases
·
They can enhance the nutritional quality
of crops
·
Their traits can provide tolerance to
Extreme temperature, Drought or Salinity
Protecting wild relatives of animals
The modern livestock production is highly
specialized and is based on very few breeds for the intensive production of
meat, milk or eggs in highly controlled conditions. They require intensive and high levels of management and high levels of inputs such as
highly digestible, high-protein feed, medication, etc. The small number of commercial
breeds suited for this kind of intensive production do not offer an adequate
genetic reservoir for the future. The turkey that is mass-produced on farms in
North America and Europe has been selected for a meaty breast and this bird can
no longer breed unassisted. This broad-breasted breed (accounts for 99 % of
turkeys in the US) would become extinct in one generation without human
assistance in the form of artificial insemination.
Several Indigenous livestock breeds often
possess valuable traits such as disease resistance, high fertility, good
maternal qualities, unique product qualities, longevity and adaptation to harsh
conditions and poor quality feed, all desirable qualities for low-input,
sustainable agriculture. The Genetic
diversity in these domestic animal breeds allows farmers to select or develop
new breeds in response to changes in the environment, threats of disease, human
nutrition requirements, changing market conditions and societal needs, all of
which are generally unpredictable.
In 1992, FAO launched a comprehensive
programme for the global conservation of animal genetic resources which
includes:
·
A global inventory of animal genetic
resources including a database to characterize and enumerate all breeds of
livestock available.
·
Action to identify breeds at risk of
extinction as well as ways of protecting them.
· Promotion of programmes in developing
countries to conserve endangered breeds in their native habitats.
·
Improvement of livestock breeding capacities
in the developing world.
Lose of wild relatives of domesticated
animals or plants due to biodiversity loss seriously threatens the resilience
of our food systems, by leaving crops and livestock genetically poorer. A
transformation in our relationship with nature is highly needed. We will need
wild relatives of important food species to ensure that genetic diversity can
enhance food security in an increasingly uncertain future. Conservation of plant and animal genetic
diversity is essential for global food security and to meet the challenges of
the future.
References
http://www.fao.org/3/v1650T0y.htm
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