Effects of elevated CO₂ and water stress on root structure and hydraulic conductance of <i>Solanum melongena</i> L

Abstract

Pot experiment was conducted using eggplants (Solanum melongena L.) grown in a controlled growth chamber environment. Ambient (370 ppm) and elevated (700 ppm) CO₂ concentrations, were used. Hydraulic conductance in stressed eggplants was lower than that of control eggplants and this phenomenon was enhanced under elevated CO₂ environment and also due to plant age. Hydraulic conductance through the root system in free water was comparatively higher than that of soil medium. As in the pressure plate apparatus technique with moist soil, the eggplants that experienced repetitively shorter stress showed the lowest conductance (6.38 × 10^-5 kg/m²/s/MPa) under the interactive effects of high CO₂ and water stress while control and longer stressed plants had 9.11 × 10^-5 and 7.19 × 10^-5 kg/m²/s/MPa, respectively. It appeared that eggplants grown in a high CO₂ environment might be efficient in water use under soil water shortage conditions.

Key words: Solanum melongena; Hydraulic conductance; Root structure; Water stress

DOI: 10.3329/bjb.v38i1.5125

Bangladesh J. Bot. 38(1): 55-63, 2009 (June