Identifying physiological and genetic determinants of faba bean transpiration response to evaporative demand.

Background And Aims: Limiting maximum transpiration rate (TR) under high vapour pressure deficit (VPD) works as a water conservation strategy. While some breeding programmes have incorporated this trait into some crops to boost yields in water-limited environments, its underlying physiological mechanisms and genetic regulation remain unknown for faba bean (Vicia faba). Thus, we aimed to identify genetic variation in the TR response to VPD in a population of faba bean recombinant inbred lines (RILs) derived from two parental lines with contrasting water use (Mélodie/2 and ILB 938/2).