Development of β-Carotene Rich Maize Hybrids through Marker-Assisted Introgression of β-carotene hydroxylase Allele

Development of vitamin A-rich cereals can help in alleviating the widespread problem of vitamin A deficiency. We report here significant enhancement of kernel beta-carotene in elite maize genotypes through accelerated marker-assisted backcross breeding. A favourable allele (543 bp) of the beta-carotene hydroxylase (crtRB1) gene was introgressed in the seven elite inbred parents, which were low (1.4 mu g/g) in kernel beta-carotene, by using a crtRB1-specific DNA marker for foreground selection. About 90% of the recurrent parent genome was recovered in the selected progenies within two backcross generations. Concentration of beta-carotene among the crtRB1-introgressed inbreds varied from 8.6 to 17.5 mu g/g - a maximum increase up to 12.6-fold over recurrent parent. The reconstituted hybrids developed from improved parental inbreds also showed enhanced kernel beta-carotene as high as 21.7 mu g/g, compared to 2.6 mu g/g in the original hybrid. The reconstituted hybrids evaluated at two locations possessed similar grain yield to that of original hybrids. These beta-carotene enriched high yielding hybrids can be effectively utilized in the maize biofortification programs across the globe.