Interactions between soil water content, stomatal conductance and abscisic acid content of field pea cultivars submitted to drought stress

Abstract

Drought is one of the main abiotic stresses limiting agricultural production of many important crops. Plants respond to drought stress by closing their stomata and reducing transpiration water loss. The drought stress experiment was conducted on seven selected cultivars of field pea in control conditions (phytotron chamber). The plants were irrigated at the optimal soil water content until the third pair of leaves began emergence, after which soil drought was induced by termination of irrigation up to 18% (moderate drought), and 9% substrate water content (severe drought). Control plants were irrigated at the optimal level of soil water regime (36% substrate water content). A measurement of stomatal conductance and ABA concentration was performed. The stomatal reactions differed between cultivars, but only under moderate drought conditions, while all cultivars reacted by the faster stomatal closure under severe drought.