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Sent: 05 June 2002 08:10
Subject: 12: GM canola - herbicide tolerance - pollen
Pollen pollution by genetically modified crops is a growing problem in North America and the problem has not been well-publicized nor has it been fairly addressed by authorities in government. Canola varieties currently marketed in Western Canada include tolerance to glyphosate, glufosinate, bromoxynil, and imidazolinone herbicides. Gene flow between cultivars with different herbicide tolerance traits has already resulted in volunteer canola with multiple resistance in a field situation in western Canada.[Volunteers crops are those that are unintentionally cultivated due to germination of seeds remaining in the ground from the previous season or that spilled at harvest...Moderator]. Canola also has weedy relatives in Canada with which it could form hybrids. For example, birdsrape mustard in eastern Canada, feral Brassica rapa canola in western Canada, and wild radish (Raphanus raphanistrum L.) in parts of both regions could be at risk of forming hybrids with herbicide-tolerant B. napus. These hybrids could serve as a bridge for gene transfer to a subsequent canola crop or else become more difficult to control because of the presence of the herbicide tolerance gene in wild populations.
Multiple herbicide resistant to glyphosate, glufosinate and imazethapyr in volunteer canola was detected in western Canada. Pollen flow between volunteer canola plants was shown to be the manner in which the resistance genes stacked to make the super resistant variety. Sequential crossing of the three individual herbicide tolerant varieties led to the formation of the final multiple resistant variety Last fall the Canadian government acknowledged that the separation distance (175 meters for production of oil and pressed seed cake for feed) between GM canola and adjacent fields was inadequate because the pollen had been observed to spread for at least 800 meters to produce two pollinations per thousand flowers at 400 meters and 7 pollinations per ten thousand flowers at 800 meters. The figure of 7 pollinations per ten thousand flowers may seem inconsequential until it is realized that each plant from a pollinated seed may produce several hundred seeds.
If the herbicide glyphosate is used to kill weeds on a field, that field can rapidly be populated with GM canola. Even without glyphosate exposure, the proportion of GM plants in a field can soon become very significant. Interestingly, the Canadian government had been aware of the problem of extensive pollen flow for some years before acknowledging it to the public. Essentially no canola grown in western Canada can be claimed to be free of gene modification and production of organic canola may not be possible in western Canada. The Canadian Food Inspection Agency that regulates GM crops in Canada seems engaged in complicity in allowing GM crops to spread throughout the farming area.
A further complication was a recent Federal Court decision that patented genes in crops that have arrived on a farmer's field by windborn pollen or seed falling from trucks are the property of the farmer onto whose field the pollen or seed had polluted the farmer's crop. However, since the genes in pollen or seed are patented the farmer whose land has been polluted cannot use the crop. The court judgment seems to allow lawyers from at least three major corporations to try to 'pick the bones' of farmers whose land has been polluted through no fault of the farmers.
Professor Joe Cummins,
University of Western Ontario.
jcummins (at) uwo.ca
Sent: 05 June 2002 09:24
Subject: 13: Re: Fundamental considerations in hazard identification of GMOs
1. Limiting concern to novel traits limits risk assessors' ability to identify hazards. Identifying that an organism was created by recombinant-DNA (rDNA) techniques does not prevent a case-by-case review, but can be an important alert. For example, when reviewing a GMO, risk assessors know immediately that they need to determine if it contains a marker conferring resistance to a medically useful antibiotic, or if it contains uncharacterized DNA, especially if transgenes originated in a pathogen or organism with allergenic properties.
2. Dr. Bradshaw stated that virtually all eukaryotes contain DNA from organisms with which they cannot breed, citing as examples DNA which has been conserved over many thousands of years (mitochondrial and relictual T-DNA) and which could hardly be compared with transgenic DNA from bacteria in corn or human DNA in pigs. GMOs are different from conventionally-bred organisms precisely because they contain exotic DNA and may act as vectors of that DNA to other members of their gene pool.
3. Dr. Bradshaw incorrectly implied that GMOs are not unique in transferring exotic genes because nearly all major crops are grown outside their native geographic range. However, regardless of where they are grown, conventional crops do not contain and cannot transfer genes from incompatible species. Conversely, a GM crop like Bt corn can transfer exotic bacterial genes both to modern corn and landraces. [Bt corn is a variety of corn genetically modified to express one of the toxin-producing genes from the soil bacterium, Bacillus thuringiensis (Bt), that confer insect resistance...Moderator]. This ability to transfer exotic genes across species is the essence of what makes GMOs unique: they are gene vectors.
Dr. Bradshaw correctly pointed out that Agrobacterium moves genes across wide phyletic divisions. However, Agrobacterium inserts its own genes into the genome of host plants; it does not transfer genes which are not its own to a third species. That occurs in the laboratories of genetic engineers, where exotic genes are inserted into Agrobacterium, which is then used to infect plants, and transfer those genes to them.
4. Dr. Bradshaw is right that transgenes are not "uniquely" unstable. My statement was that GMOs are "inherently" unstable because of the way they are made: they contain genes removed from regulatory controls; insertional mutations increase the probability of silencing via repair mechanisms; the location and number of transgenes cannot be controlled; and transgenic promoters may activate host genes or retroviral DNA. There are already numerous examples of instability (inconsistent phenotype) in GMOs, the most famous being boll drop and malformation in glyphosate-resistant GM cotton in 1997 in Louisiana.
5. When he points out that mutations have been important in agricultural breeding, Dr. Bradshaw incorrectly implies that the use and implications of mutations in historical and modern breeding and genetic engineering are similar.
Historically, breeders selected plants and animals with useful, but spontaneous mutations. Recently breeders have intentionally created mutations with radiation. With rDNA techniques, mutations are an unintentional but necessary by-product of inserting foreign genetic material into the host genome. Methods which intentionally or unintentionally create mutations are highly inefficient because mutations kill most of the offspring or render them undesirable. Moreover, organisms created this way, even if at first apparently predictable, have a high probability of exhibiting unexpected behavior.
6. Even though Dr. Bradshaw states that there is "no such thing as a promoter gene," conference participants should not get the mistaken impression that promoters do not exist. Promoters are genetic sequences added to GMOs to activate transgenes, and as such are one of the unique features of rDNA techniques which makes it important for risk assessors to know if a new crop or animal is a GMO.
Suzanne Wuerthele, PhD, toxicologist
US Environmental Protection Agency (EPA)
e-mail: Wuerthele.Suzanne (at) epamail.epa.gov
Sent: 05 June 2002 09:33
Subject: 14: Transgene flow to maintain genetic diversity
I am Saturnina C Halos, a molecular geneticist with a plant breeding background providing advice on biotechnology policy and program in the Philippines.
I think that transgene flow from GM varieties to non-GM populations could be exploited by a developing country with limited resources to help maintain genetic diversity. There are possible cases when transgene flow from GM varieties to non-GM populations helps save genetic diversity and exploiting it could make for a cost-effective government program of saving biodiversity. For example, we are currently having problems with a viroid disease called cadang-cadang which is wiping out coconut plantations. Suppose we have a GM-coconut with a gene that protects it from this disease, will it not be to the advantage of the native coconut populations to naturally acquire such a gene? Will it not be a most cost-effective eradication program for government to develop and require the planting of such GM-variety in the middle of different non-GM coconut plantations (coconut is cross pollinating) so that the gene is naturally spread especially since there is no control measure for this disease?
A similar situation exists with our abaca, banana and papaya where natural and cultivated populations are decimated by virus and fungal diseases. In some provinces, a native banana variety is no longer commonly found in backyards where 20 years ago they are a common sight. The papaya industry of one province was already destroyed by a virus disease. What we need to realize is that even natural plantations are in a constant state of flux because of its pests and its environment. In leaving them alone we could eventually lose these populations.
The current practise of transferring a transgene to as many popular varieties as possible also helps maintain genetic diversity at the farm level. It makes sense to adopt this as a government policy. On the other hand, the natural transfer of helpful genes from GM to non-GM varieties would be advantageous to a small farmer since he/she will not incur any additional cost besides giving him/her some peace of mind knowing that his/her crop will provide yield and income.
Saturnina C. Halos
Senior Project Development Adviser
Bureau of Agricultural Research
Tel No. 63(2)920-0239
halos (at) mozcom.com
Sent: 05 June 2002 16:11
Subject: 15: GM crop gene flow - developing countries
As a person from a developing country, Sri Lanka, and having also lived in India for the past five years, I think I can address some issues pertaining to GM crop cultivation in the developing world.
Unlike farmers in US or in Canada, who own hundreds of hectares of land, farmers from the developing countries do their cultivation in small plots. In this scenario, it is not at all possible to prevent gene flow from GM to non-GM crops and there will not be any space left to set up a refuge. Also, the farmers from these countries are poor, and already are under the burden of increasing prices of agricultural inputs in the open economy of these countries. And usually these farmers are living under the pressure of loans borrowed for cultivation. In this context, if a farmer from these developing countries is sued by giant GM seed-producing companies for breach of patents, then these farmers will be helpless and one cannot imagine their plight, how they could bear the penalties or fight the court cases.
Alternatively, we can uplift these poor farmers' living conditions by applying the 'Biovillage Concept' conceived in India. Biovillage is a concept of farm transformation through application of proven biotechnologies at grassroot level, with integration of the best traditional technologies to enhance the livelihood security of rural people. It has been designed for sustainable agriculture and runs on the theme of pro-poor, pro-women and pro-ecofriendly. The biotechnologies involved are micropropagation, biofertilizer, bio-pestcontrol, bioenergy, vermiculture, mushroom culture and aquaculture, floriculture, meat and dairy production. Biovillage programmes have become successful in India and could be applied to other developing countries too.
M.Sc- in Biotechnology
Postgraduate Institute of Agriculture,
University of Peradeniya,
muhunthan_r (at) yahoo.com