Non-invasive phenotyping of drought response in bread wheat genotypes using GM2 and MCARI1 indices

Drought stress poses a significant threat to wheat productivity, necessitating the development of rapid and non-destructive methods for assessing plant responses to water scarcity. This study evaluates four local bread wheat genotypes (Zirva 85, Murov 2, Aran, and Gyzyl bughda), with varying drought tolerances, using remote sensing-based vegetation indices: the Gitelson and Merzlyak Index (GM2) and the Modified Chlorophyll Absorption in Reflectance Index 1 (MCARI1). Seedlings were grown under controlled and drought conditions, and their physiological responses were measured through spectral reflectance. Results showed genotype-dependent variations in GM2 and MCARI1 indices under drought conditions, with drought-tolerant genotypes maintaining more stable chlorophyll content and photosynthetic efficiency compared to drought-sensitive ones. This study highlights the utility of GM2 and MCARI1 indices as effective tools for monitoring drought-induced physiological changes.