Friday, July 29, 2011
Field-evolved resistance to Bt maize by western corn rootworm
By Aaron J. Gassmann*, Jennifer L. Petzold-Maxwell, Ryan S. Keweshan, Mike W. Dunbar
(Department of Entomology, Iowa State University)
July 29, 2011
Background: Crops engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) are planted on millions of hectares annually, reducing the use of conventional insecticides and suppressing pests. However, the evolution of resistance could cut short these benefits. A primary pest targeted by Bt maize in the United States is the western corn rootworm Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae).
Methodology/Principal Findings: We report that fields identified by farmers as having severe rootworm feeding injury to Bt maize contained populations of western corn rootworm that displayed significantly higher survival on Cry3Bb1 maize in laboratory bioassays than did western corn rootworm from fields not associated with such feeding injury. In all cases, fields experiencing severe rootworm feeding contained Cry3Bb1 maize. Interviews with farmers indicated that Cry3Bb1 maize had been grown in those fields for at least three consecutive years. There was a significant positive correlation between the number of years Cry3Bb1 maize had been grown in a field and the survival of rootworm populations on Cry3Bb1 maize in bioassays. However, there was no significant correlation among populations for survival on Cry34/35Ab1 maize and Cry3Bb1 maize, suggesting a lack of cross resistance between these Bt toxins.
Conclusions/Significance: This is the first report of field-evolved resistance to a Bt toxin by the western corn rootworm and by any species of Coleoptera. Insufficient planting of refuges and non-recessive inheritance of resistance may have contributed to resistance. These results suggest that improvements in resistance management and a more integrated approach to the use of Bt crops may be necessary.
Tuesday, July 26, 2011
The great food labelling debate
By Lucy Sharratt
July 26, 2011
After 16 years of bitter negotiations, the world reaches agreement on the labelling of genetically modified foods.
While consumer groups around the world celebrated the July 5 United Nations Codex agreement on labelling genetically modified (GM) foods, the biotechnology industry argued that the final document achieved nothing new. In fact, industry came close to denying there was an agreement at all. After 16 years of negotiations, these two radically different responses to the final document can be explained by the high stakes involved, arguably the future of global markets for GM foods.
It is voluntary and now technically “guidance” rather than “guidelines,” but the new international agreement on labelling GM foods, two decades in the making, was bitterly fought over. The biotechnology industry, with its initial power base in the U.S. and Canada, is adamantly opposed to labelling, afraid that, given the choice, consumers around the world will reject GM foods, as seen in Europe. The stakes were so high that the U.S. government – with varying support from Canada and a handful of food exporting countries, including Argentina and Australia – continually tried to stop the Codex negotiations altogether. After two decades, however, food safety regulators from around the world finally agreed upon a few words that have huge global import.
The Codex Alimentarius Commission is the global food standards-setting body of the UN Food and Agriculture Organization and the World Health Organization. Most importantly, it is the reference point for food standards under the World Trade Organization (WTO) and is used in settling trade disputes. According to consumer groups, the new Codex document provides nations with protection from trade challenges over GM food labelling laws.
Saturday, July 23, 2011
Genetically modified crops safety assessments
By Gilles-Eric Séralini, Robin Mesnage, Emilie Clair, Steeve Gress, Joël Spiroux de Vendômois, Dominique Cellier
Environmental Sciences Europe
Purpose: We reviewed 19 studies of mammals fed with commercialized genetically modified soybean and maize which represent, per trait and plant, more than 80% of all environmental genetically modified organisms (GMOs) cultivated on a large scale, after they were modified to tolerate or produce a pesticide. We have also obtained the raw data of 90-day-long rat tests following court actions or official requests. The data obtained include biochemical blood and urine parameters of mammals eating GMOs with numerous organ weights and histopathology findings.
Methods: We have thoroughly reviewed these tests from a statistical and a biological point of view. Some of these tests used controversial protocols which are discussed and statistically significant results that were considered as not being biologically meaningful by regulatory authorities, thus raising the question of their interpretations.
Results: Several convergent data appear to indicate liver and kidney problems as end points of GMO diet effects in the above-mentioned experiments. This was confirmed by our meta-analysis of all the in vivo studies published, which revealed that the kidneys were particularly affected, concentrating 43.5% of all disrupted parameters in males, whereas the liver was more specifically disrupted in females (30.8% of all disrupted parameters).
Conclusions: The 90-day-long tests are insufficient to evaluate chronic toxicity, and the signs highlighted in the kidneys and livers could be the onset of chronic diseases. However, no minimal length for the tests is yet obligatory for any of the GMOs cultivated on a large scale, and this is socially unacceptable in terms of consumer health protection. We are suggesting that the studies should be improved and prolonged, as well as being made compulsory, and that the sexual hormones should be assessed too, and moreover, reproductive and multigenerational studies ought to be conducted too.
Thursday, July 21, 2011
Farmers using even more pesticides with GM crops
By Ken Roseboro
The Organic & Non-GMO Report
July 21, 2011
Proponents of genetically modified crops have long claimed that GM crops would reduce pesticide usage, but government statistics show that claim to be false.
According to the 2010 Agricultural Chemical Use Report released in June by the US Department of Agriculture’s (USDA) National Agricultural Statistics Service (NASS), use of the herbicide glyphosate, associated with genetically modified crops, has dramatically increased over the last several years, while the use of other even more toxic chemicals such as atrazine has not declined. The data show that overall use of pesticides has remained relatively steady, while glyphosate use has skyrocketed to more than double the amount used just five years ago.
The report shows that in the states surveyed, 57 million pounds of glyphosate were applied last year on corn fields. Ten years prior, in 2000, this number was only 4.4 million pounds, and in 2005, it was still less than half of current numbers at 23 million pounds.
GM proponents claim glyphosate reduces the need for farmers to use older, more toxic herbicides such as atrazine. Also not true. In 2000, 54 million pounds of atrazine were applied across surveyed states, by 2005 57.4 million pounds were used, and in 2010, the total dipped slightly to 51 million pounds.
New rules urged on hybrid animal-human experiments
By Ben Hirschler
July 21, 2011
LONDON - Scientific experiments that insert human genes or cells into animals need new rules to ensure they are ethically acceptable and do not lead to the creation of “monsters,” a group of leading British researchers said on Friday.
While humanizing animals in the name of medical research offers valuable insights into the way human bodies work and diseases develop, clear regulations are needed to make sure humanization of animals is carefully controlled.
Extreme scenarios, such as putting brain cells into primates to create talking apes, may remain science fiction, but researchers around the world are constantly pushing boundaries.
Chinese scientists have already introduced human stem cells into goat fetuses and U.S. researchers have studied the idea of creating a mouse with human brain cells — though they have not actually done so.
Such controversial research needs special oversight, according to a report from Britain’s Academy of Medical Sciences on the use of animals containing human material.