Food and
Agriculture Organization (FAO) of United Nations estimates 40 countries have
large amount of food insufficient for their population. This account almost 1
out of 7 billion of total population of world. In one part of the world
excessive food and obesity is becoming a serious problem day by day, in other
part (developing and least developed countries) people are dying out of hunger.
In contrary to this, human population is growing and mouths to feed has
increased, at the same time, land to grow is becoming limited. It comes with a
challenging situation to plant science to develop high yielding and
disease/pest resistant crops.
A series of
improvement in plant sciences has been found. Since the beginning of
civilization and domestication of agricultural practices, selection of crops
for better traits and high productivity continued. This was noticed clearly
after Mendel’s work in nineteenth century. By then, selection was the
established method for improvement in crop breeding. A good example here comes
from Corn (Zea mays), which is a
modern crop introduced from years long selection process of Teosinte (Zea Mexicana). Now corn is totally
dependent on humans for survival. Selection is still a prominent and effective
method of crop improvement in plant breeding.
Early part of
twenty century in United States was a productive era in plant breeding science.
This led to development of high yielding varieties, which need higher doses of
fertilizers, pesticides, mechanization and irrigation. Transformation for these
technologies continued to developing countries over past 40 years, which led to
higher productivity in agriculture production system. This achievement is known
as Green Revolution.
Dr. Norman
Borlaug led green revolution was possible due to development of high-yield
varieties. Development and extension of dwarf strain of wheat in Mexico (by
CYMMIT) and rice in Philippines (IRRI).
At the same time disease-resistant varieties of crops which are able to
stand against many bacteria, fungi, viruses and nematodes were developed. It was a breakthrough in agricultural science,
the benefit of this spread away to Asia and Africa too. Countries like India,
Pakistan and china were benefited largely by this.
Green revolution
was not a miracle without high rate of input supply. Thus, there came some
problems, mostly in developing countries. Critics blame green revolution as a
costlier technique and environmentally not safe. More on this, genetic
diversity of the plants are also eroded. As there needed high dose of
pesticides and fertilizer, adequate irrigation and high mechanization,
developing part of the world suffered from inadequacy. This lead to salinity in
soil.
Solution to
problem led by green revolution should start from the part of the world where
population is very high. Development in improved irrigation system, organic
fertilizers, biological control of pest and diseases may reduce the negative
impact of green revolution by a large part.
Erosion of
genetic diversity starts from monoculture practices. Monoculture is growing the
same crop year after year in a large region. Not only crop, this has narrowed
down to some selected varieties of crops only. For example, half of the wheat acreage
in the United States is planted with just nine varieties of wheat. Sustainable agriculture on other hand consist
of mixture of annual and perennial crops, which can be harvested for a number
of years without replanting.
As traditional
varieties ( land races) are abandoned and replaced with modern , high yielding
varieties and as habitat destruction brings about the extinction of wild
relatives, valuable genetic heritage is lost forever, which is known as genetic
erosion. This erosion can be reduced by gene or seed banks. In U.S. seed bank
is located at National Centre for Genetic Resources Preservation in Fort
Collins, Colorado under USDA in 1958. More than 500,000 seed samples
representing 8,000 species are housed there.
Liquid nitrogen under at very low temperature is used as preservative.
Heirloom varieties or traditional varieties are encouraged to cultivate for their
preservation.
Germplasm is the encoded
information of a plant, the genetic instructions that dictate not only the type
of the plant but also all the traits unique to an individual plant. Germplasm
is the center of an international controversy, the question of ownership. In June 2004, the international Treaty of
Plant Genetic Resources for Food and Agriculture was enacted to protect
valuable genetic resources. Ratified by 55 nations, the treaty defines plant
genetic resources as “any genetic material of plant origin of actual or potential
value for food and agriculture.”
FAO has
identified some of the potential alternative crops. Alternative crops can be
brought to the attention of global agriculture and can be diversify the world’s
food sources. Quinoa is one of them, which is found in South America. Grain amaranth is another new world crop
under development for world market. A South
America legume called Tarwi has been taken in interest in recent days. Similarly Tamarillo and naranjilla two
relatives of tomatoes are also identified as good alternative to vegetables
supply. Tamarillo is tree tomato. Oca is a tuber crop as of wheat potato, which
is from Andes.
Biotechnology is
use of living organism to provide products for humanity. Cell and tissue
culture is one of the established biotechnology technique where whole plant is
developed from a single cells. Small pieces of plant tissues are grown in a
nutrient medium supplemented with plant hormones, after a few days, the cells
begin dividing and produce a small, undifferentiated mass of tissue known as a
callus. Similarly molecular plant
breeding technique uses marker assisted selection process for identification
and incorporation of some special traits that are not identifiable through
phenotype.
The genetic engineering,
especially the recombinant DNA technology is a new and major changing
technology in field of plant breeding.
While traditional methods of plant breeding allows the transfer of
useful genes within a species or closely related species, genetic engineering allows the transfer of useful genes from one
organism to a totally unrelated plant species. Organism with foreign gene are called
transgenic. The development of
transgenic plants begins with the identification and isolation of the useful
trait containing gene and useful vector to transfer that. Use of Plasmids or
gene gun shoot can be done for gene transfer.
Genetic
engineering has two major traits developed in plants. First one is herbicide
resistance. Bacterial gene that confers
resistance to the herbicide glyphosate has been introduced in many plants. However there are lot of cases where farmers
are against the developer of these kind of traits. In 2002, Monsanto a seed
company which developed herbicide resistant wheat variety was objected by
farmers. Country like Japan and South Korea objected those wheat crops
containing herbicide resistant. Insect resistance is another trait that is
developed in crops through genetic engineering. Bacillus thuringiensis (Bt) a common soil bacterium is used for
insect resistance trait.
There is
widespread adoption of Bt corn, as it is resistant to European corn borer. A
study in 1990 at Cornell University charged the Bt corn for harming monarch
butterfly population. There are subsequent studies, which proves that fining was
not correct. However, this controversy is still there. The genetic engineered
golden rice which contains Beta Carotene (converts into Vitamin A) is being
developed as a new tool to eradicate malnutrition problem. Later Bill and Melinda Gates Foundation has
funded for addition of vitamin E, more protein and enhanced iron and zinc
availability in same rice variety.
There are many
crops beyond staple food which are genetically engineered like soybean, alfalfa,
tomato, and canola. New traits like disease resistance is being developed in
genetically engineered crops. Genetic engineering
being used to produce rice plants resistant to a devastating disease called
leaf blight, caused by the bacterium Xanthomonas
oryzae.
The scope of
biotechnology extends beyond food crops. One of the promising use is in
pharmaceuticals to produce many vaccines and medicines. Also, since 1990s,
there are a lot of ongoing greenhouse and field trials of GM trees in 16
countries. In 2010 USDA approved for eucalyptus tree.
There are many
issues with GM crops. Issue on regulation is one of them. In 1992 Food and Drug
Administration (FDA) developed a policy on GE crops, recommending that “developers
consults with FDA about bio-engineering foods under development”. If the FDA feels that GM variety is not safe
for marketing comparing with other non GM food, by testing 120 days before that
food is marketed, there would be ban on marketing. Environmental Protection
Agency (EPA) evaluates any possible effects on non-target organism. The U.S.
Department of Agriculture (USDA) monitors the field crops that are genetically
engineered.
Critics argue
that GM crops are seriously affecting our environment, can harm human health
and benefits only large agribusiness conglomerates. GM crops are questioned all
over the world. Zambia refused US food aid in 2002 with fear of GM. European
countries were more cautious, however, recent days they started to grow GM
crops. There is concerns over transfer of herbicide resistant gees from GM
crops to other related species. Also, natural development resistant in weeds
are also questioned. Use of terminator
gene is also questioned seriously in developing nations, so that same seed cannot
be planted and has to depend on seed companies year after year. So there is
also blame for super insect development and killer weeds development having
developed the resistance against GM. Though there are any issues against GM, the National
Research Council in 2010 resealed a report saying on impact of GM crops in American
farmers. The report has found economic and environmental benefits rather than
harm.
In conclusion,
there are questions against use of Biotechnology. However, biotechnology is found
useful in many ways. It is needed to feed the growing population which signifies there would be
further development in biotechnology in days to come.
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