lunes, septiembre 10, 2007

Sorgo transgénico

Letter to the editor of the Cornell Daily Sun about genetically engineered sorghum

In a recent article in the Sept 7,2007 Cornell Daily Sun (CU Research May Help Farmers Improve Annual Yield by Eve Waters), once again there may be more hype than substance. Ms Waters: "Leon Kochian, the research leader and supervisory plant physiologist at the United States Plant, Soil and Nutrition Laboratory USDA-ARS and a Cornell adjunct professor in plant mineral nutrition, has been working on isolating this gene for over ten years." Mr Kochian and a Brazilian colleague, Jurandir Magalhaes, were able to isolate and clone an aluminum-resistant gene in sorghum plants that allows them to grow in acidic soil. On the surface, this sounds good. There was nothing in the story about intellectual property rights and who "owns the genes and the seeds" and the added costs for ag-inputs.

Doug Gurian-Sherman, Ph.D., Senior Scientist at The Center for Food Safety, International Center for Technology Assessment in Washington, DC, has several points worth noting about this research. His response: "As is usually the case for this kind of research, it is discussed in a vacuum that ignores other approaches and issues. Aside from the soil issues that are not addressed by this approach, it also does not discuss the possibility of using conventional breeding to accomplish the same thing. Since a single gene is responsible for the trait, it would probably not be too difficult to accomplish by traditional breeding. Or marker assisted selection could be used to speed up the process. Sorghum is highly diverse, with many land races, especially in Africa. They may argue that it would be faster to get this gene into different varieties using GE, but that is highly debatable, since much time-consuming screening must be done to find transformation events that do not have undesirable agronomic properties."

The lack of long term studies on the unintended effects of these new technologies poses problems as well. Mr. Gurian- Sherman: "Field trials that are done for current GE crops, despite the assertions of the industry, are mainly to check these agronomic properties, not for environmental safety. There have usually been dozens or hundreds of field trials for new transformation events for the first generation GE crops, largely for this reason.

"Even when this is done, unexpected things are seen after commercialization, like the recently reported higher aphid numbers on Bt corn, or stem cracking of RR soybeans in heat. If the process is cut short, there is a greater chance that such negative properties will go unnoticed. Ecologists know that even many field trials are likely to miss many important unexpected changes in the ecology of the crop."

What benefits exist in replacing the knowledge and seeds that already exist in a region? What about the genetic diversity already in the areas for which these new "technologies" will be replacing, as well as the added cost? If we look at the adoption of bt cotton in India, the problems farmers faced led to massive suicides. Gurian-Sherman: "Look at the adoption of Bt cotton in Warengal India, as documented by Dave Stone. Poor farmers may replace their landraces for the immediate benefit of aluminum tolerance, only to find five years latter that the variety is susceptible to a previously minor insect or pathogen (as is occurring with Bt cotton in China and India)."

Unless the political will exists to improve infrastructure and land reform for poor farmers, it is unlikely that the problem of aluminum soil toxicity and other issues will solve many of the problems farmers must confront. Gurian-Sherman: "I doubt that there would be the effort to make sure that genetic variation would be maintained in poor tropical countries where aluminum soil toxicity is most often a problem." Biotech companies are not interested in assisting farmers as much as they want to profit from and control food production.