Plant Breeding as a tool to cope with drought using the HvFSDI gene

Abstract

Drought stress is a major constraint to wheat and barley production, causing oxidative damage, metabolic disturbances, and reduced crop productivity under changing climatic conditions. Understanding the physiological and biochemical mechanisms associated with drought tolerance is essential for identifying resilient cultivars and supporting the development of climate resilient cereal production systems. The physiological, biochemical and agronomic responses of two varieties of barley to two irrigation periods: P1 - irrigation every 15 days and P2 – irrigation every 20 days) were evaluated in the winter season 2024 at the University of Baghdad, using a randomised complete block design with factorial arrangement and three replications. Growth characters, activities of antioxidant enzymes (CAT, SOD and GPX) and yield attributes and grain yield were measured. Variety 1 was superior to variety 2 in agronomic performance. Variety 2 had significantly higher plant height (79.6 cm), leaf area (10.95 cm2), number of spikes (250.08 spikesm2), kernels per spike (48.9) and grain yield (4.63 t/ha) than variety 1. The second irrigation period (P2) improved plant height, number of spikes, number of kernels per spike and grain yield and the activities of SOD and GPX, indicating better antioxidant responses against oxidative stress. However, CAT activity was higher in P1, indicating higher detoxification of hydrogen peroxide in shorter irrigation intervals. In general, the interaction between Variety 2 and P2 yielded the highest values of growth, antioxidant activity and yield. These results indicated that Variety 2 had better physiological and biochemical mechanisms to cope with drought stress and produced more under prolonged irrigation interval.