Morphological and anatomical response of Acacia ehrenbergiana Hayne and Acacia tortilis (Forssk) Haynes subspp. raddiana seedlings to induced water stress

Abstract

The response of Acacia ehrenbergiana Hayne and Acacia tortilis (Forssk) Haynes subspp. raddiana seedlings to 100, 50 and 25% field capacity (FC) watering regimes was studied to determine their morphological and anatomical behaviour. Both species responded morphologically as well as anatomically to water stress. Water stress caused significant (P=0.05) decrease in relative water content, leaf number and area and leaf water potential, chlorophyll content, and stem height and diameter. Seedlings of both species responded to water stress by the development of longer roots. Vessel segment length, radial diameter, tangential diameter, wall thickness and density were significantly (P=0.05) affected by water stress at 25 and 50% FC. It can be concluded that both species can adapt well under dry conditions.

Keywords: Anatomical deviations, drought, morphological response, root elongation