Comparison of PC (μmol/gDW) and WS (from 0 to 9) between ISR42-8 (ISR) and Scarlett (SCA) under control and drought stress conditions. Trait values have been averaged across years 2007, 2008 and 2009. PC was measured according to Bates et al. . WS was assessed by a visual scoring from 0 to 9 according to de Datta et al. .