Climate change caused drought stress to become a critical challenge in maize (Zea mays L.) production, surpassing other environmental stresses. Understanding drought resilience mechanisms in maize is essential for breeding drought-tolerant varieties. This study evaluated the drought tolerance of two maize hybrids, Sancia and Agrister, under greenhouse conditions with four irrigation regimes: 90%, 75%, 50%, and 25% of field capacity (FC). Under severe drought (25% FC), the hybrid Agrister showed reductions in shoot length, leaf area, biomass, and chlorophyll content by 13.9%, 29.86%, 30.76%, and 13.7%, respectively, compared with well-watered conditions (90% FC). In both hybrids, electrolytic conductivity increased under drought, indicating membrane stress. Agrister, however, maintained lower levels of hydrogen peroxide (H₂O₂) than Sancia, signaling a better antioxidative balance. A higher catalase and peroxidase enzyme activity marked Agrister’s response to drought, alongside increased phenolic compounds, strengthening its antioxidant defense system. The study concludes that Agrister’s superior drought tolerance makes it a promising candidate for cultivation in Tunisia’s arid regions, highlighting its potential in breeding programs focused on resilience to water scarcity.

Keywords: Maize (Z. mays L.), drought stress, chlorophyll content, biochemical traits

Key findings: Maize (Z. mays L.) hybrid Agrister excelled the hybrid Sancia under water-deficit conditions and showed better development of aerial parts and a higher drought tolerance. The genetic variability between the two maize hybrids highlights the potential for breeding drought-resistant maize.