Screening for durum wheat (Triticum durum Desf.) cultivar resistance to drought stress using an integrated physiological approach

Drought is one of the major abiotic stresses with a detrimental impact on plant growth and development irrespective of the developmental stage. Thus, identifying the physiological mechanisms driving drought resistance in crops remains challenging. Drought tolerance was evaluated in nine durum wheat cultivars (Triticum durum Desf.) at an early stage of plant development using plants grown under hydroponic conditions. Young wheat plants were subjected to three polyethylene glycol (PEG) treatments (0%, 1.8%, and 2.6%) over 21 days. Nineteen morpho-physiological parameters were then measured to monitor the impact of drought stress caused by the presence of PEG. An integrative analysis allowed the identification of genotypes exhibiting various levels of tolerance to drought, also revealing the impact of water deficiency on key phenotypic and physiological markers. Among the nine wheat genotypes, the landrace INRAT 69 was the most tolerant, whereas the commercial cultivar Ben Bechir was the most sensitive. We also found that amino acid, total soluble sugar, proline, and starch contents were the physiological parameters that were the most representative of drought stress. The use of these parameters as marker traits to select drought-tolerant wheat genotypes at early stages of plant development is discussed. © 2020, Korean Society of Crop Science (KSCS).