Effects of growth conditions on the physicochemical, mineral, and amino acid profile of polyembryonic maize

Abstract

Background and Objective: Among the methods to improve the quality of maize (Zea mays L.) kernels is crossing with better-quality genotypes and agronomic management. In this study, the quality (lipids, proteins, crude fiber, carbohydrates, ashes, minerals, and amino acids) of polyembryonic (PEm) and nonpolyembryonic (NPEm) maize was evaluated in individual plants (IND) as polyembryonic (PE). Three different genotypes (AE = high polyembryony hybrid maize, NAP = normal-height high polyembryony maize, and CAI = NPEm hybrid) were selected; in addition, maize kernels were obtained under different growth conditions of population density (HD = high density and LD = low density) and fertilization rates (LF = low fertilization [120 N, 60 P, 0 K], and HF = high fertilization [40 N, 90 P, 0 K]). Findings: The results indicate that PEm has higher protein (10.3%) and fat (7.5%) content and lower carbohydrate content (2.0%) than CAI. The highest concentration minerals were P, S, Cl, K, Ca, and Fe in all maize genotypes. In addition, NAP of IND plants had a higher content of serine, tyrosine, phenylalanine, glutamine, and alanine. On the other hand, in the experiments where the effect of population density and fertilization level was evaluated, it was observed that PEm produced with LD showed higher ash, fiber, and carbohydrate content (1.1%, 1.4%, and 2.7%, respectively) and lower fat content (6.0%). In addition, PEm produced in HD showed higher values of fat, protein, fiber, K, P, and S than the control group (CAI). Finally, PEm produced with LF showed higher proportions of fat, protein, fiber, K, and P (5.7%, 8.2%, 1.1%, 5.8 mg/100 g, and 1.6 mg/100 g, respectively) compared to the control group (CAI). In addition, fertilization was observed to influence carbohydrate content, showing an increase of up to 24% in HF and up to 10% in LF. Conclusion: The combined use of corn of polyembryonic genotypes with different agronomic managements such as stocking density (LD and HD) and fertilization rate (LF/HF) during grain production can generate significant changes in grain quality. Significance and Novelty: The use of polyembryonic maize genotypes is an option to improve grain quality. In addition, the results of this study allowed us to observe the effect of agronomic practices such as planting population density and fertilization rate on different variables of interest for grain quality.