Lecture 10 Flashcards
glyphosate
member of a class of herbicides that inhibit amino acid biosynthesis
Bt
Bacillus thuringiensis; spore forming bacterium which kills insects
bt-expressing crops
insect resistant crops which produce Bt proteins
what is the most widely grown Bt crop?
transgenic cotton; defends against tobacco budworm and cotton bollworm
what does Bt-crops reduce the need for
insecticide use in agriculture
what is the danger of a diet based on rice
vitamin A deficiency
Beta-carotene transgenic rice
produces increased levels of beta-carotene in the endosperm providing a means of preventing Vitamin A deficiency in humans; 3 genes must be transferred to make this transgenic crop
ISAAA
international service for acquisition of agri-biotech applications; agency that produced 2016 report on biotech information with the goal of sharing info globally to allow countries to have better access to biotech and grow better crops
1st gen biotech crops
1996-2016; single trait; herbicide tolerance, disease and insect resistance; 4 major crops: soybean, cotton, corn, canola
2nd gen biotech crops
2013-2016; double trait; stacked traits; insect resistance AND herbicide tolerance
3rd gen biotech crops
2017-; tolerance to climate and abiotic stressors; enhanced nutritional quality for humans and livestock; reducing food waste; eg. drought tolerant corn; ex. tomatoes traditionally selected for how they look but they have lost nutrients and flavour; now adding back nutrients lost over generation
1996-2016 biotech trends
shirt from first gen to second gen crops; 2014 noticed a shift from herbicide or insect resistant crops to stacked trait crops with both; use in developing nations surpassed developed nations in 2010
biotech crops common in Canada
herbicide resistant canola
herbicide resistant soybeans
herbicide resistant sugar beet
Bt & herbicide resistant corn
biotech crops in USA
same as canada plus Bt cotton and virus resistant Papaya
HR crops
Herbicide Resistant; conventionally you need to spray whole field before seeding, now you can let crop grow then spray only where there are weeds because crop will be safe.
conventional herbicide practice
till field, spray field with herbicide, seed
benefits of HR crops
reduced tilling, reduced erosion, reduced water loss, reduced herbicide use, reduced greenhouse gas emissions
bt corn
different bt proteins protect corn from various species of borer or rootworm, highly specific for particular pests; grown in Ontario and Quebec;
how much has bt corn increased farm income
5 fold since 1997 due to savings from reduced pesticide use and increased yield
how much has bt corn reduced pesticide use
25,000kg/year
SmartStax corn
2 herbicide resistance genes, 3 Bt genes for aboveground insects, 3 Bt genes for below ground insects; 8 transgenes total
benefit of smatstax corn
multiple mechanisms of insect resistance reduces likelihood of insects developing resistance which prolongs the arms race between plant resistance and insect
what increase in yield has smarstax corn resulted in
8.7bushel/acre increase in Ontario and Quebec
ethical considerations of GM crops
some claim gene transfer among organisms is unethical because humans should not alter organisms in such profound ways violating nature; opposite view is that traditional breeding has the same effect
environmental considerations of GM crops
unlikely that transgenic crops will become weeds because the gene alteration is relatively small; slight potential for transgenes to be transferred to wild relatives through interbreeding; herbicide use will eventually select for resistant weeds; pests will eventually become resistant to gm plants
environmental solutions for environmental issues of GM crops
reduce outcrossing of crop with week relatives; integrate weed management by alternating herbicide used and ploughing fields periodically to reduce weed pressure
Refuges
non Bt-plants where susceptible insects can survive to mate with resistant insects reducing the number of resistant insects
pest resistance in US corn belt
2012 problems with corn root worms becoming resistant to Bt corn; vast land area of mono crop corn; same Bt corn used every year with limited refuges producing perfect conditions for selecting resistant root worms
Bt crops effect on non target organisms
kill insects which are prey for many animals and insects. however Bt toxin degrades rapidly in soil, and is specific to certain organisms unlike many pesticides
why won’t transgenes be transferred to humans
stomach acid breaks down food into amino acids, nucleotides, lipids, sugars
could a new gene product be an allergen
unlikely, but genome sequencing could be used on new crops to screen for allergen indicators; to date an allergic reaction has not been linked to gm foods
anti-corporate arguments for GM crops
argument that corporations aren’t interested in human health just profit, but if not for their profit they would not have finances to invest in R&D to make new products that will benefit human health
IPM
integrated pest management system; crop rotations (plant crop resistant to pathogens of previous crop, plant legumes to restore soil fertility), scout for pests and apply pesticide where needed, use of natural predator insects, green manure
intellectual property rights, patenting of genes
DNA is a chemical, chemicals can be patented; without patents, companies would not invest in R&D and no products would be developed outside of universities
can genes be patented In canada
genes can still be patented, this is being challenged in a federal court, manipulation of genes to improve an organism can also be patented
are GMOs allowed in Europe
only 3 European countries allow GMOs; difficult to get approval
how are GMOs regulated in Canada
1993 Federal Framework for regulating Biotech products; plants with new traits assessed regardless of breeding or transgenetics used to develop them
Process of getting a crop approved in canada
- testing crops with novel traits before commercialization–laboratory or greenhouse research–fieldtrials
2 safety assessment and risk management–decisions made by Agriculture Canada–if approved, confined field trials are done–monitoring done for years to ensure safety - unconfined field trials–receives health canada approval for food/feed use
- commercialization
cost of creating a new transgenic crop in N. America
high value traits like HR corn 35-136million USD to meet biotech regulations which prevents small companies from entering the biotech industry
low value traits in developing nations 2million USD
GM crop benefits
increased productivity; reduced cost of production; reduced environmental impact; enhanced farm level economic gain; (less ploughing, fewer pesticides and herbicides, less labour, all result in reduced cost, environmental impact and increased profit.)
how do GM crops reduce CO2 emissions
reduced tilling and herbicide sprays
EIQ
Environmental impact quotient; environmental impact=toxicity*potential for exposure; EIQ can be done for farmer, picker, consumer, environment, only considers toxicity
what do GM crops do to EIQ
reduce the EIQ due to lower insecticide and herbicide use
how do GM crops affect land use
reduction in land use due to increased productivity and yield per hectare
FAO-OECD Outlook Report 2010
Food and Agriculture Organization of the UN; Organization for Economic Co-operation and Development; compared crop production in EU and GM producing countries over several years and predicted 4% increase in European productivity and 15-40% increase in GM countries between 2010-2019
organic farming
natural fertilizers; risk for contamination with human pathogens; no synthetic -icides; no GM seeds, IPM used;
Conventional/Gm farming
synthetic&natural fertilizers; less human pathogen contamination issues; synthetic pesticides are more targeted; use GM seeds; higher average yields
conventional/molecular breeding
limited to exchanges between closely related plants; small chance of obtaining a gene, millions of crosses done and screening of crosses; undesirable genes transferred 7-12years to obtain crop
genetic engineering
direct transfer of 1+gene between close or distantly related species; 2-5 years to obtain crop
