Variations in physiological traits as screening tool for drought tolerance in barley (Hordeum vulgare L.)

Abstract

The utilization of physiological traits in genetic improvement of drought tolerance in barley (Hordeum vulgare L.) requires establishment of significant association between grain yield and the physiological traits and their genetic variations. The study was aimed at to determine variability in yield-attributes, yield and physiological traits in advance F6 lines and commercial varieties of barley, and to establish the relationship among these characters in irrigated (2 irrigations at 40 and 80 days after sowing) and rainfed (no post sowing irrigation) conditions. Yield attributes, yield and physiological traits decreased significantly in rainfed than irrigated condition. Biomass was positively and significantly associated (R2 = 0.82, P < 0.001) with grain yield. Rates of photosynthesis (Pn) of flag leaf were positively related to biomass (R2 = 0.68, P < 0.001) and grain yield (R2 = 0.52, P < 0.01). Midday (1200–1400 h) leaf relative water content (RWC) showed strong association with Pn (R2 = 0.90, P < 0.001) and biomass (R2 = 0.65, P < 0.001). Since, RWC being a simple and inexpensive trait to measure, showing strong association with Pn and biomass, which determined grain yield, could be employed as a tool to screen barley genotypes for drought tolerance.