Measuring leaf temperature and stomatal conductance to evaluate leaf water content in barley cultivars under terminal drought stress

Abstract

Drought stress is the main abiotic stress that limits crop production especially cereals that cope with water limitation in reproductive stage in semi arid areas. In this study, stomatal conductance and leaf temperature were consider as the precise and non destructive methods to evaluate water status in 3 barley cultivars under stress (withholding irrigation from anthesis until the end of growth season), and non stress (normal) conditions. The experiment was conducted in factorial based on CRD with three replications in greenhouse in Iran. Results indicated drought stress conditions significantly reduced leaf water content, stomatal conductance, cell membrane stability, number of tiller per plant, grain yield and harvest index. On the other hand, drought stress increased leaf temperature and hollow percent of grains in all cultivars (P<0.01). A significant correlation was observed between grain yield and stomatal conductance (r=+0.94), water content (r=+0.95), leaf temperature (r=-0.66), cell membrane stability (r=+0.62), number of tiller per plant (r=+0.65), number of grain per spike (r=+0.51) and harvest index (r=+0.96) in 20 days after anthesis. According to significant correlation between stomatal conductance and leaf temperature with other traits, using the infrared thermal image and prometer as the reliable methods to study water status in drought stress condition instead of other destructive methods are