BELTSVILLE, Md.—Agricultural Research Service (ARS) researchers and colleagues at Purdue University and the International Maize and Wheat Improvement Center (CIMMYT) have identified two genes in corn that are linked to higher beta-carotene levels, and developed a cheaper and faster way to screen corn plants for more genes that will produce even higher levels of the essential nutrient. The research is expected to at least triple the levels of carotenoids in Africa’s corn and could increase levels in some varieties far beyond that, according to Edward Buckler, a geneticist in ARS’s Robert W. Holley Center for Agriculture and Health in Ithaca, N.Y.
Researchers surveyed the genetic sequences of diverse corn from around the world and found two naturally mutated genes, each producing an enzyme at lower levels than those found in most corn varieties. Plants with either gene mutation have higher levels of beta-carotene, and plants with both mutations have higher levels still.
After genes are identified via association mapping, markers can be developed from these genes to allow for marker-assisted selection, which is much simpler, faster, and “up to 1,000-fold cheaper” than running the types of chemical tests previously used, Buckler said.
Scientists in developing countries now can cross the newly identified high beta-carotene lines with local varieties and, applying the markers developed from these two genes, choose progeny that are adapted to local growing conditions but still retain high beta-carotene. The team hopes supplying corn with high beta-carotene levels will help address the ongoing problem of vitamin A deficiency, a major cause of blindness in children in many developing nations.
