STUDY ON GROWTH AND STOMATAL RESPONSE OF YOUNG POPLAR PLANTS SUBJECTED TO PARTIAL SOIL DRYING

Abstract

Growth and stomatal response of young poplar plants, grown with part of the roots in drying soil, were studied in the greenhouse of Edinburgh University, United Kingdom as a method of species selection for dry areas. Water relations of leaves and abscisic acid (ABA) content of both leaves and roots were investigated while the roots in moist soil profile were being able to maintain shoot water supply. Leaf and stem growth in association with leaf stomatal conductance were reduced in plants subjected to partial soil drying despite the maintenance of leaf turgor potential. The simultaneous presence of higher ABA content both in roots and leaves over the period of soil drying indicates the influence of signals from roots of drying soil in these reductions. These earlier responses of shoot to soil drying could maintain sustained productivity of plants through sustained utilisation of water in water shortage areas.