Enhancing kernel oil and tailoring fatty acid composition by genomics‐assisted selection for dgat1‐2 and fatb genes in multi‐nutrient‐rich maize: new avenue for food, feed and bioenergy

Abstract

SUMMARYEnhancing maize kernel oil is vital for improving the bioavailability of fat‐soluble vitamins. Here, we combined favourable alleles of dgat1‐2 and fatb into parental lines of four multi‐nutrient‐rich maize hybrids (APTQH1, APTQH4, APTQH5 and APTQH7) using marker‐assisted selection (MAS). Parental lines possessed favourable alleles of crtRB1, lcyE, vte4 and opaque2 genes. Gene‐specific markers enabled successful foreground selection in BC1F1, BC2F1 and BC2F2, while background selection using genome‐wide microsatellite markers (127–132) achieved 93% recurrent parent genome recovery. Resulting inbreds exhibited significantly higher oil (6.93%) and oleic acid (OA, 40.49%) and lower palmitic acid (PA, 14.23%) compared to original inbreds with elevated provitamin A (11.77 ppm), vitamin E (16.01 ppm), lysine (0.331%) and tryptophan (0.085%). Oil content significantly increased from 4.80% in original hybrids to 6.73% in reconstituted hybrids, making them high‐oil maize hybrids. These hybrids displayed 35.70% increment in oil content and 51.56% increase in OA with 36.32% reduction in PA compared to original hybrids, while maintaining higher provitamin A (two‐fold), vitamin E (nine‐fold), lysine (two‐fold) and tryptophan (two‐fold) compared to normal hybrids. Lipid health indices showed improved atherogenicity, thrombogenicity, cholesterolaemic, oxidability, peroxidizability and nutritive values in MAS‐derived genotypes over original versions. Besides, the MAS‐derived inbreds and hybrids exhibited comparable grain yield and phenotypic characteristics to the original versions. The maize hybrids developed in the study possessed high‐yielding ability with high kernel oil and OA, low PA, better fatty acid health and nutritional properties, higher multi‐vitamins and balanced amino acids, which hold immense significance to address malnutrition and rising demand for oil sustainably in a fast‐track manner.