“This [form of breeding] used to take 6-15 years,” says Ismail. “Now we can have a tolerant variety in only 2-3 years.”
And it seems to work. Tests have shown that fields planted with the hybrid that experienced flooding show average yield gains of close to one ton per hectare, says Ismail.
Their submergence-resistant rice has been distributed to farmers in India, Bangladesh, Nepal, Indonesia and the Philippines. IRRI hopes it will reach 5 million farmers in Asia and Africa by 2014 and 20 million farmers by 2017.
Vitamin shake
Increasing the amount of food we produce is one thing. Producing nutritious food is another, according to Yassir Islam, spokesperson for HarvestPlus, a non-profit organisation looking to improve nutrient content in staple foods.
He says the next green revolution will have to be accompanied by a rethink about how nutritious the food is that we put on the table of millions of people every day. Too many people in Asia and Africa already suffer from what HarvestPlus calls “hidden hunger”, or deficiencies in key micronutrients. These people live in parts of the world where their diets are dominated by staples – foods such as rice, wheat, cassava, millet and maize – that are high in calories but lack iron, zinc, vitamin A and other micronutrients. Deficiencies can reduce IQ, lower disease resistance, stunt growth and even cause blindness, which greatly increases a person’s risk of death in the developing world.
The best-known example of boosting nutrition in staple crops is golden rice, which has been engineered with genes from daffodils and bacteria to produce beta-carotene, a nutrient that the body can convert into vitamin A. Developed in the 1990s, and field tested in the 2000s, golden rice is still not available for general use. Some environmental groups, including Greenpeace, fear that this genetically modified strain could contaminate and harm other vital rice strains.
But rather than importing genes from another organism, researchers are now trying to find maize strains that naturally produce high levels of beta-carotene. Torbert Rocheford of Purdue University, Edward Buckler of Cornell University, and their collaborators screened around 300 maize strains, and unearthed some with boosted beta-carotene levels. They then looked for any genes in these maize strains that resembled genes linked to high beta-carotene levels in other plants.
“It’s the sort of process where either you hit a grand slam home run or strike out. There’s nothing in between,” says Rocheford.
They scored, finding a small number of maize varieties that grow in both tropical and temperate climates and which carry a gene variant that slows down the conversion of beta-carotene to other substances, leaving more to make vitamin A. As important, they also found a genetic marker that signals when this sought-after gene variant is in place.
Plant breeders are using the naturally occurring maize plants and those markers to breed new plants. So far, the process has boosted concentration of beta-carotene in the corn from practically nothing to about 8 micrograms per gram – around 53% of HarvestPlus’ target for the micronutrient. The organisation expects to release corn that achieves that target in 3-4 years.
What will really determine its success is if farmers will regularly plant this orange corn in a region where people traditionally eat white corn with no beta-carotene. This year, HarvestPlus, which like the IRRI is funded by the Bill and Melinda Gates Foundation, is releasing the fortified corn in Zambia, where more than half of children experience vitamin A deficiencies. The plan is to eventually adapt the plants to fields elsewhere in Africa, in Latin America and in Asia.
