Monday, October 31, 2005

The Color Orange: Key to More Nutritious Maize?

SeedQuest -- CIMMYT maize scientists and colleagues from national programs in the key countries targeted by HarvestPlus reported significant progress in identifying maize with elevated concentrations of iron, zinc, and pro-vitamins A (chemicals the human body can convert to vitamin A) in their elite maize varieties and germplasm collections. The results of two years of work were presented at the second HarvestPlus Maize meeting hosted by EMBRAPA, the national agricultural research program of Brazil at their maize and sorghum research station in Sete Lagoas.

Maize is a key target crop for nutritional enhancement because it is so widely consumed in areas where high malnutrition—especially vitamin-A deficiency—exists. Scientists working in the HarvestPlus program hope eventually to breed high-quality, high-yielding maize with enhanced pro-vitamins A, iron, and zinc content. These micronutrients in maize will have to be in a form that survives processing and can be utilized by the human body.

The first planning meeting for the maize scientists was held in 2003 in Ethiopia. “We’ve come a long way since we first met two years ago,” says Kevin Pixley, the HarvestPlus Maize coordinator and Director of CIMMYT’s Tropical Ecosystems Program. “But we have also realized that this is a very complex subject with many assumptions that have to be validated.”

CIMMYT maize breeder Dave Beck showed the group results of screening of CIMMYT elite highland and transition zone maize germplasm for enhanced levels of pro-vitamins A, zinc, and iron. HarvestPlus nutritionists have set minimum targets for the concentrations of these micronutrients in maize. The good news is that for zinc, CIMMYT has identified material that was already above the threshold. For iron the picture is less promising as existing lines identified have only 60 percent of the required minimum level for iron. For pro-vitamins A CIMMYT has examined hundreds of lines. The best CIMMYT lines have about 75 percent of the minimum requirement, but sources identified by project partners in the USA have the minimum required level of pro-vitamins A. The CIMMYT team is now breeding to enhance pro-vitamins A concentration for highland, transition zone, mid-altitude, and lowland-adapted materials.

A topic of keen interest at the meeting was how to convince people to adopt any nutritionally enhanced maize varieties that might be developed. In much of eastern and southern Africa, white maize is preferred over yellow maize. Scientists in Zambia and Zimbabwe had conducted studies about the acceptability of yellow maize. Both studies found that yellow maize is associated with food aid and that was one reason people did not want to eat it. Scientists know there is a strong correlation between the color of the maize and the total level of carotenoids. Some of these carotenoids are precursors for vitamin A “pro-vitamins A.” Torbert Rocheford, a professor of plant genetics at the University of Illinois, suggested that the debate should not actually be about yellow maize in many parts of Africa. He said what we should be talking about is orange maize—something new that will not carry the stigma of yellow maize but will have high pro-vitamins A content.


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IOL -- The majority of South Africans are unaware that 30 percent of the country's yellow maize and soy bean crops are genetically modified.

This is just one of the concerns raised by international author Jeffrey Smith, who is in the country to deliver a series of talks on genetically modified food.

Smith was addressing a group of people on the topic at the Diakonia Centre in Durban on Thursday.

He is also author of the book, Seeds Of Deception: Exposing Industry And Government Lies About The Safety Of The Genetically Engineered Food You're Eating.

Smith said that genetic engineering involved taking a gene from one species and inserting it into another.

Smith said that most South Africans had no idea that the food they were eating had been genetically modified.

"South Africa is the only country in the world allowing its staple food to be genetically modified and as a result, is putting a large portion of the population at risk," said Smith.

He said that 30 percent of the country's yellow maize and soy bean crops were genetically modified, along with 10 percent of white maize crops.

Smith said that the genetically modified maize grown in South Africa is likely to have been inserted with a gene that would make it produce Bt-toxin, which is a pesticide.

"When this pesticide was fed to mice, the mice developed an immune response equal to that of cholera toxin. They developed allergies, abnormal and excessive cell growth in their small intestines, and a greater susceptibility to allergies," he said.

Smith said the GM Bt-toxin in maize was hundreds and even thousands of times more concentrated than the spray form.

"Farm workers exposed to even the low dose Bt spray showed evidence of allergic sensitivity.

"Preliminary evidence found that 39 Filipinos living next to a Bt maize field developed skin, intestinal and respiratory reactions while the maize was pollinating," he said.

Smith said that farmers who fed their cattle 100 percent GM maize had difficulties.

"Twelve cows died on a German farm, and about 25 farmers in North America said their pigs became sterile, had false pregnancies or gave birth to bags of water."

Smith said that South Africans needed to take a stand and demand to know what goes into the food they are eating.

"We need the leadership of this country, the faith-based leadership, the labour leaders and those who protect the lives of those with HIV/Aids to put a stop to these genetically modified foods.

"Leaders have to go to the government and manufacturers, and tell them that we (the public) are going to get our congregations and organisations to stop eating GM foods, and ask for a list for those which are GM and those which are not," he said.

Smith said that only when the word was out and everyone knew what was genetically modified and what was not, would a revolution begin within the industry.

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