Evaluation of potentially high yielding modern wheat cultivars for drought tolerance using key physio-biochemical and morphological indicators

Abstract

Wheat is the main trading crop, driving food security and the worldwide economy. Severe drought stress is a chief threat to wheat productivity in existing climatic variations. Screening of wheat cultivars based on metabolic strategies to tolerate drought stress is crucial to ensure better yield. Current research work is carried out to evaluate drought-sensitive and tolerant wheat cultivars based on physio-biochemical and morphological stress indices. A pot experiment was organized according to factorial CRD with four replications. Ten latest high-yielding wheat cultivars were selected, and seeds were sown in pots having loamy soil and divided into two treatment portions. One was treated with control (NoDS) conditions, and the other with severe drought conditions (DS). Drought stress caused a significant decline in fresh and dry weight of roots and shoots, length of roots and shoots, leaf area and chlorophyll contents. However, enhanced production of reactive oxygen species (H 2 O 2 ) and lipid peroxidation (MDA) ultimately triggered enzymatic antioxidant (SOD, POD, CAT) activities. All wheat cultivars exhibited osmotic modification by accumulating total soluble proteins (TSP) and free amino acids (FAA). According to our findings, Akber-19 performed better under control (NoDS) conditions among all cultivars. However, it is quite sensitive under severe drought (DS) stress. In contrast, Fakhar-e-Bhakkar significantly maintained osmotic and antioxidative balance under drought stress (DS) and exhibited more tolerant behaviour than other cultivars at the seedling stage.