Genotype by Environment Interaction in Grain Iron and Zinc Concentration and Yield of Maize Hybrids under Low Nitrogen and Optimal Conditions

Sajjad Akhtar; Tesfaye Walle Mekonnen; Gernot Osthoff; Kingstone Mashingaidz; Maryke Labuschagne

doi:10.3390/plants12071463

Genotype by Environment Interaction in Grain Iron and Zinc Concentration and Yield of Maize Hybrids under Low Nitrogen and Optimal Conditions

Plants (Basel). 2023 Mar 27;12(7):1463. doi: 10.3390/plants12071463.

Authors

Sajjad Akhtar¹, Tesfaye Walle Mekonnen¹, Gernot Osthoff², Kingstone Mashingaidz³, Maryke Labuschagne¹

Affiliations

¹ Department of Plant Sciences, University of the Free State, Bloemfontein 9300, South Africa.
² Department of Microbial Biochemical and Food Biotechnology, University of the Free State, Bloemfontein 9300, South Africa.
³ ARC-Grain Crops, Potchefstroom 2520, South Africa.

Abstract

Maize is the staple food crop for millions of people in sub-Saharan Africa. Iron (Fe) and zinc (Zn) deficiency is a significant health risk that mainly affects low-income populations who rely solely on maize-based diets. This problem can be alleviated by developing micronutrient-rich maize grain. The aim of this study was to determine the adaptation and performance of hybrids for Fe and Zn concentration and grain yield under low soil nitrogen (N) and optimal conditions. Eighteen hybrids derived from lines and testers with low, medium, and high Fe and Zn concentration were grown during the summer rainy seasons of 2017 and 2018 at three locations under low and optimal N conditions. There were significant genotype and environment effects for grain yield, and Fe and Zn concentration, but the genotype by environment interaction effects were the largest, accounting for between 36% and 56% of variation under low N conditions. Low N levels significantly reduced grain yield, and Fe and Zn concentration. Hybrids G1, G2, G4, G7, G10, G11, and G16 were relatively stable, with relatively high mean Fe and Zn concentrations, and low additive main effects and multiplicative interaction (AMMI) stability values and iron stability index (FSI) and zinc stability index (ZSI) under low N conditions. These genotypes can be considered for production under low N stress conditions. Two environments (E4 and E3) were identified for good discriminatory power for genotype performance in terms of Fe and Zn content, respectively. Stable and high-yielding genotypes with high Fe and Zn concentration can be used as biofortified hybrids, which can contribute to a sustainable solution to malnutrition in the region, especially under low N conditions.

Keywords: GEI; biofortification; iron; low N; maize; zinc.

Grants and funding

This study was funded by the National Research Foundation (NRF), South Africa, through the South African Research Chairs Initiative (UID 84647), and The World Academy of Sciences, Italy.