winsem2014-15_cp2186_11-mar-2015_rm01_gm-crops
DESCRIPTION
GM CROPSTRANSCRIPT
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Dr. S. Mohana Roopan
What are GM crops / food? According to ‘World Health Organisation’:“Genetically modified (GM) foods are foods derived from organisms whose
genetic material (DNA) has been modified in a way at does not occurnaturally, i.e. through the introduction of a gene from a differentorganism”. GM Crops are described by many different names –
•Genetically Engineered crops(GE)•Transgenic or Biotech crops•Genetically Modified Organism(GMO)
BT Gene BT Gene inserted into DNA of the crop
Genetically Modified Plant
Injected
Genetically modified crops
Insect Resistance
Herbicide Tolerance
Drought resistance
Yield increase
Nutrient Enhancement
Virus Tolerance
‘Advantages’ of GM Crops 1) Insect Resistance (IR) Insect pests have become an integral part of agricultural crops worldwide
and significantly reduce yield of the plants. So IR trait is inserted into crops.
IR trait is helpful in following ways:•Reduction in Insecticide spraying.•Targeting of the insecticide solely to the plant to be protected .
GM plant
Killed
European Corn Borer
Toxin is Present
European Corn Borer(Insect)
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2) Herbicide ToleranceOver 63% of Gm crops grown globally have herbicide tolerance traits. Herbicide tolerance is achieved through the introduction of a gene from abacterium conveying resistance to some herbicides. In situations whereweed pressure is high, the use of such crops has resulted in a reduction in thequantity of the herbicides used.
GM crop
GM Crop(Unaffected) Weed KilledWeed
Herbicide Spray
Result OfHerbicide Spray
3) Drought Resistant
Genetically Modified Crops requires less
water for their growth , hence are capable
to sustain in drought conditions.
Useful in areas which receive less rainfall.
4) Virus ResistanceVirus resistance makes plants less ‘prone’ to diseases caused by such
viruses, resulting in higher crop yields.
For Example- Hawaiian Papaya- Hawaiian papaya is made resistant to the
devastating effects of Papaya Ring Spot Virus (PRSV).
Hawaiian Papaya Papaya Ring Spot Virus
5) Nutrient Enhancement White rice is a staple food in most countries.
It provides 80% daily calories.
Concern Arises
White rice doesn’t contain beta-carotene which human body converts it
to Vitamin A.
WHO says 5 Lakh people get blind due to vitamin A deficiency every year .
To tackle this beta-carotene is added to white rice to make “Golden Rice”.
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Adding Nutritive Value
Gene added from:-1. Maize or Daffodil Plant2. Common soil bacteria (Erwinia)
Lycopene
Beta-carotene
Yellow-Orange rice grainOr
Golden rice
White Rice
Golden Rice is rich in Vitamin A
6) Yield Increase
Conventional Seeds
Genetically Modified Seeds
Low yield
High yield
Food shell life Increase
TransportationBy variousmeans
Storage
• Spoiling of vegetable decreases.• The first genetically modified crop
approved for sale in the U.S. was the Falvr Savr tomato.
Ware-House
Genetically modified crops
Allergenicity
Gene transfer
Outcrossing
Super Weeds
‘Disadvantages’ of GM Crops
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1) AllergenicityIn India, hundreds of laborers picking cotton and working in cotton ginningfactories developed allergic reactions when handling the BT cotton. Thisdidn’t happen with the non-Bt varieties. [Ashish Gupta et. al., “Impact of BtCotton on Farmers’ Health (in Barwani and Dhar District of Madhya Pradesh),”Investigation Report, Oct–Dec 2005]Hospital records: “ Show that victims of itching have increased massivelythis year, and all of them are related to BT cotton farming.” [The SundayIndian, 10/26/08]
Itching all over the body, eruptions, wounds, discoloration
2) Out-crossing(Gene Transfer)The movement of genes from GM plants into conventional crops or related
species in the wild (referred to as “out crossing”), as well as the mixing of
crops derived from conventional seeds with those grown using GM crops,
may have an indirect effect on food safety and food security.
pollens
Direction of wind
GM Crops Conventional crops
Super Weeds :A wild plant that has been accidentally pollinated by a genetically-modified plant and now contains that plant's abilities to resist herbicides and insects.Glyphosate is the chemical name for an herbicide. Certain invasive grasses and weeds have proven themselves to be resistant to glyphosate, meaning that the herbicide is no longer effective against these plants.Examples of weeds resistant to Glyphosate:
•Common Ragweed•Italian Ryegrass
3) Super Weeds
pollens
WeedGM Crop
Cross Pollination of GM crop With Weeds
Super Weed
Herbicide Spray
GM Crop Super Weed
No Effect of Herbicide Spray
GM Crop
Conclusion GMO’s present both positive and negative aspects to society as a whole.
They are a topic of much deliberation and tension; very prevalent in some
parts of the world and banned in others.
GM crops are required for meeting Food Security in today’s growing
population.
Ultimately, GMO’s are still a relatively premature technology and in the
developmental process. Only time will reveal their ultimate effect on
humans !
(Play)
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