23 March, 2010, Danstan Kaunda
Variations of a maize gene
A team of scientists in Washington DC has discovered rare variations of maize gene (crtRB1) that can lead to an 18-fold increase in beta-carotene content of maize in an academic research setting, says the HarvestPlus report recently released.
“We are on track to release conventionally-bred vitamin A maize in Zambia by 2012—beyond that, this research could accelerate breeding of maize with even more vitamin A,” said Dr. Howarth Bouis, Director of HarvestPlus.[frax09alpha]
HarvestPlus alongside with the United States funded agency USAID and other organizations are spearheading the research which has reached advantage stage. Under the best scenario, the crtRB1 gene variations can increase concentration of beta-carotene from a little above zero, to about 57% of the micronutrient target (15 micrograms/gram beta-carotene) that HarvestPlus has determined would improve poor people’s nutrition and health mostly in developing countries.
Plant breeders are starting to use these naturally occurring genetic variations to breed maize that can provide more beta-carotene to malnourished people. The body converts beta-carotene into vitamin A.
Millions of people in developing countries are too poor to buy foods rich in beta-carotene, such as fruits and vegetables. This result in vitamin A deficiency, which blinds up to 500,000 children annually scientists predicts. The poor eat cheaper staple foods, such as maize, daily. Increasing the amount of naturally produced beta-carotene in maize can upgrade its status to a ‘superfood’ that provides a valuable nutrient in addition to calories.
Most of the beta-carotene produced in maize is converted into other carotenoids, which make less or no vitamin A. The favorable variations of the crtRB1 gene slow down this conversion process resulting in more beta-carotene, and hence, more vitamin A. The team also identified a molecular marker, essentially a genetic signpost, which makes the most favorable form of the gene easier to find.
“We can now, not only search for this form of the gene in maize using cheap molecular markers, but also breed it into any maize variety in the world,” says Dr. Torbert Rocheford, a member of the team. “This could translate into improving the health of children through better nutrition, especially in Africa where maize is a popular staple food.”
Zambia, like several other countries in the Central and Southern African region, has been hit by a food shortage time again; a situation that has led the government to declare most parts disaster areas.
In 2002 Zambia experienced hunger following a severe drought. The US government offered generticall engineered maize as relief to assistance Zambians but the then republican President Levy Mwanawasa rejected the offer, citing health, environmental, trade and market- share concerns.
His decision came after a team of scientists and economists was sent on a fact-finding mission to South Africa, Europe and the United States.We are on track to release conventionally-bred vitamin A maize in Zambia by 2012—beyond that, this research could accelerate breeding of maize with even more vitamin A,” said Dr. Howarth Bouis, Director of HarvestPlus.
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