THE RESPONSE OF HUMULUS LUPULUS TO DROUGHT: THE CONTRIBUTION OF STRUCTURAL AND FUNCTIONAL PLANT TRAITS

Abstract

The work summarizes information about key processes and structural traits that may affect water use in hop plants and how these traits affect plant response to drought. We measured changes in the transpiration rate, leaf water potential and stem hydraulic conductance in response to declining water availability in soil in several hop cultivars. We also explored the anatomical traits of xylem in the stem. We investigated structural and functional traits that may represent potential limitations in hop plants. Plants showed decreased transpiration rates and shoot water potential under declining water availability. We found that hop cultivars differ significantly in some traits that underlie water use such as the rate of transpiration and leaf water potential. These differences probably do not relate to differences in water transport in xylem and xylem anatomy. More likely, they are connected to differences in processes that regulate stomatal aperture in leaves.