Marker-Assisted Genetic Enhancement of Provitamin A in Parental Lines of Sweet Corn Hybrids

Abstract

Sweet corn is cultivated worldwide in tropical and temperate regions, and it is consumed favorably due to its sweet taste, but it is poor in provitamin A carotenoids. For these reasons, by adopting a marker-assisted backcross breeding (MABB) approach, we aimed to enhance the β-carotene concentration in sweet corn inbreds (USC1-2-3-1, SC1107, and 12039-1), which are the parents of popular sweet corn hybrids. β-carotene-rich inbred lines UMI1230β⁺ crossed with these inbreds and progenies are selected based on the gene-specific markers (foreground selection) and SSR markers (background selection). As a result, four improved lines from each cross, viz., USC1-2-3-1 × UMI1230β⁺, SC1107 × UMI1230β⁺, and 12039-1 × UMI1230β⁺ with high β-carotene concentration and good agronomic performance (>80%) were obtained. These lines were used to produce hybrids with improved vitamin A content. Furthermore, the improved lines were used to develop the hybrids and tested along with the original hybrids. The hybrids produced by crossing improved lines were on par with the original hybrids regarding grain yield and sweetness with an added advantage of β-carotene. These improved β-carotene-rich sweet corn inbreds and hybrids have enormous potential to reduce malnutrition in a sustainable and economical way.