Deciphering the physio-biochemical dynamics of wheat (T. T. aestivum L.) genotypes during water deficit stress

Water deficit stress poses a significant challenge to wheat cultivation worldwide, necessitating the identification of indicator traits for plant productivity under such conditions. This study investigated the physiological and biochemical responses of four wheat varieties (C-306, DBW 110, DBW 136, and GW 451)under varying levels of water deficit stress (100%, 75%, and 35% FC). The results indicated that increasing water deficit stress resulted in notable decreases in physiological parameters such as the relative water content (RWC), chlorophyll content, chlorophyll stability index (CSI) and membrane stability index (MSI) at both the booting and grain filling stages. In response to water deficit stress, the plants increased their levels of proline, total soluble sugars (TSS), total phenol and free amino acids (FAA). Furthermore. oxidative damage, indicating that parameters such as proline concentration and malondialdehyde (MDA) content increased. Water deficit conditions markedly promoted the activities of key antioxidant enzymes, including catalase and peroxidase. Among the varieties, C-306 and DBW 110 were less affected by water deficit stress, as shown by significant changes in their physiological and biochemical parameters. These results highlight the importance of assessing physio-biochemical traits related to phenotypic water deficit stress tolerance in wheat varieties, providing valuable insights for breeding programs aimed at developing and selecting drought-tolerant cultivars.