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.

Enhancing 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.

Unraveling popping quality through insights on kernel physical, agro-morphological, and quality traits of diverse popcorn (Zea mays var. everta) inbreds from indigenous and exotic germplasm.

Popcorn is a specialty corn with worldwide popularity as a snack. Despite having great market demand, genetic improvement in popping quality is limited, which is caused by the limited germplasm utilization and narrow genetic base. An assortment of diverse germplasm, their effective characterization, and integration into popcorn breeding pipeline is the foundation for an efficient breeding program. Here, kernel characteristics, popping quality traits, and agro-morphological traits were evaluated across three locations on a diverse panel of 48 popcorn inbreds derived from diverse landraces and populations of exotic and indigenous origin. The variations due to genotypes, locations, and genotype × location interaction were highly significant. The popping quality traits recorded wide variation with a high coefficient of genotypic determination. The kernel dimensions, kernel density, test weight, and grain yield were negatively correlated with popping quality traits. Genotypes with rice-type kernels exhibited better popping quality than pearl-type kernels. Analysis of genotype × location (G×L) interaction identified two target locations for the key popping quality trait, popping expansion volume. PMI-PC-175, PMI-PC-187, PMI-PC-188, and PMI-PC-189 were identified as superior genotypes over checks for desirable popping quality, agronomic performance, and high grain yield. The contrasting inbreds for popping quality and flake shape (mushroom vs. butterfly) can be utilized for developing mapping populations to enhance our understanding of molecular aspects of popping quality traits. Further, the promising inbreds can be utilized in the genetic improvement of popcorn and crossed to develop superior popcorn hybrids. The results suggest a potential opportunity to establish an efficient popcorn breeding program.

Maize genotypes with favourable dgat1-2 and fatb alleles possess stable high kernel oil and better fatty acid health and nutritive indices.

Diverse uses of maize oil attracted various stakeholders, including food, feed, and bioenergy, highlighting the increased demand for sustainable production. Here, 48 diverse sub-tropical maize genotypes varying for dgat1-2 and fatb genes governing oil attributes, were evaluated in three diverse locations to assess trends of oil content, fatty acid (FA) profile, the effect of environment on oil attributes, the impact of different gene combinations and determine FA health and nutritional properties. The genotypes revealed wide variation in oil content (OC: 3.4-6.8 %) and FA compositional traits, namely palmitic (PA, 11.3-24.1 %), oleic (OA, 21.5-42.7 %), linoleic (LA, 36.6-61.7 %), and linolenic (ALA, 0.7-2.3 %) acids. Double-mutants with both favourable alleles (dd/ff) exhibited 51.6 % higher oil, 33.2 % higher OA, and 30.2 % reduced PA compared to wild-types (d+d+/f+f+) across locations. These double-mutants had lower saturated FA (12.2 %), and higher unsaturated FA (87.0 %), indicating reduced susceptibility to autooxidation, with lower atherogenicity (0.14), thrombogenicity (0.27) and peroxidisability (48.15), higher cholesterolemic index (7.16), optimum oxidability (5.27) and higher nutritive-value-index (3.35) compared to d+d+/f+f+, making them promising for significant health and nutritional benefits. Locally adapted stable novel double-mutants with high-oil and better FA properties identified here can expedite the maize breeding programs, meeting production demands and addressing long-standing challenges for breeders.