Breeding Tropical Maize with Increased Beta-Carotene Content

Naturally- occurring alleles that help control beta-carotene levels in grain are being bred intro tropical maize, thus increasing as much as five-fold its beta-carotene content. Results of this finding were reported in Nature Genetics online.

 "Maize is a major food crop in Latin America and Africa, serving as a key source of carbohydrates, proteins, and other nutrients, but it's generally poor in pro-vitamin A," said Yan Jianbing, CIMMYT scientist and lead author of the study. "The favorable alleles we found were associated with as much as a five-fold increase in maize grain beta-carotene concentrations over normal levels."

According to a CIMMYT feature article, the research team of 21 international experts from 11 research institutes surveyed naturally-occurring variants of the gene Zea mays β-carotene hydroxylase 1 (crtRB1), which is associated with the conversion of beta-carotene in maize kernels. The pro-vitamin A grain concentrations they found suggest that, with the help of two genes, alleles for crtRB1 and for lycopene epsilon cyclase (lcyε), it will be possible to breed tropical maize varieties with 15 micrograms of beta-carotene per gram of grain.

The CIMMYT feature article on this study is at http://www.cimmyt.org/english/wps/news/2010/apr/vitaminA.htm