Enrichment of β carotene content in maize inbred UMI 1201 through marker assisted back cross breeding

Abstract

Maize is a good source of provitamin A for humans. A promising approach to eliminating Vitamin A deficiency (VAD) in developing countries like India is to biofortify maize genotypes with micronutrients like β - carotene. This study was therefore designed to increase the β-carotene concentration in the maize inbred UMI 1201, the female parental line of the popular maize hybrid COH(M)8 by marker assisted backcross breeding (MABB). The crtRB1 enriched β carotene inbred, UMI 1230β⁺, was utilized as the donor parent. In the MABB program, crtRB1 3′TE, the gene-specific marker for β carotene was used for foreground selection and 105 SSR markers were used for background selection. Four enhanced UMI 1201 lines for β carotene concentration were identified with good agronomic performance and recurrent parent genome recovery (RPGR) ranging from 91.0 to 94.0percent. The improved lines outperform the recurrent parent UMI 1201 in terms of β carotene accumulation which ranged from 7.73 to 10.37 µg/g., with UMI 1201β⁺-2 being the most effective. The grain yield of the improved lines ranged from 2308 kg/ha to 2519 kg/ha. Morphological resemblance of the improved lines recorded more than 90% of phenotypic similarity with the recurrent parent UMI 1201 for the traits viz., anthocyanin colouration of the brace roots (present), attitude of leaf blade (straight), leaf width of blade (Narrow), tassel anthocyanin colouration of glume excluding the base (present), tassel anthocyanin of anthers (present), ear anthocyanin coloration of silks (present), ear shape (cylindrical) and kernel row arrangement (straight). The introgressed inbred possessing the crtRB1 allele can be used as donor for β carotene enrichment in the biofortification program.