Screening of Wheat (Triticum aestivum L.) Genotypes for Drought Tolerance through Estimation of Chlorophyll and Proline Contents

Wheat (Triticum aestivum L) is a staple food cereal crop for the majority of the global population. Water scarcity is a major challenge to wheat productivity under changing climate conditions, especially in arid and semi-arid regions. During recent years, different agronomic, physiological, and molecular approaches have been used to overcome the problems related to drought stress. The adverse effects of single or multiple environmental stresses, such as drought, high and low temperatures, and nutrient deficiencies on plant growth and yield have become severe in recent years due to increased global climate change and the occurrence of extreme weather events. This study was designed to investigate the screening of wheat genotypes under drought and irrigated conditions and to identify the best-performing genotypes under both conditions. Five different genotypes were used in two factors and three replications at Gomal University, Dera Ismail Khan, and investigated for yield and drought tolerance under irrigated and drought conditions by the estimation of chlorophyll and proline contents. Data collected for yield/pot (g) and drought tolerance by estimating chlorophyll and proline contents was subjected to Statistix 8.1 software at the 5% probability level. Results revealed significant differences (P ≤ 0.01) among genotypes for chlorophyll and proline contents, and yield/pot. Under both irrigated and drought treatments, AZRC Dera exhibited the highest chlorophyll content value (46.33 and 45.11, respectively), followed by RK-2022 (43.32 and 41.89, respectively). Similarly, under drought stress conditions, RK-2022 (20.21) and AZRC Dera (18.86) recorded the accumulation of the highest proline content, followed by Wadan (18.21). Moreover, the irrigation treatments and stressed plants varied the grain yield from 0.72 to 0.49 and 0.52 to 0.28 grams/plot, respectively. AZRC Dera and RK-2022 exhibited a higher yield/plot (g) under both irrigated (0.72g and 0.65g, respectively) and drought (0.52g and 0.48g, respectively) conditions. Considering yield and drought-responsive high chlorophyll and proline contents, AZRC Dera and RK-2022 showed greater drought tolerance and revealed potential to grow under water deficit conditions in comparison to other cultivars.