Flag leaf senescence, carbon content and carbon isotope discrimination in durum wheat grown under semi-arid conditions

Flag leaf senescence was compared among twenty-one durum wheat genotypes grown under semi-arid conditions in the Algerian High-Plateau using numerical image analysis. A significant correlation was found between senescence at the end of the grain filling period and grain yield. Carbon content of the flag leaf at anthesis (CL) also correlated with grain yield. The association between grain yield and carbon isotope discrimination (Δ) in flag leaves was not significant. A negative correlation between Δ and CL revealed that genotypes with high transpiration efficiency (low Δ) had higher carbon content in the leaves. Results suggest that high flag leaf carbon content at anthesis and low senescence at the end of grain filling are positively associated with grain yield under drought and heat stress.