Differential response of two acacia species to salinity and water stress

Abstract

Salinity and drought are two important environmental problems responsible for the reduction of growth and yield of many plant species. The present study was conducted to evaluate the tolerance potential of A. nilotica and A. ampliceps against salinity and water shortage in the pots. Different salinity levels (control, 10, 20 and 30 dS m-1) were developed in the pots by adding calculated amount of NaCl. Three months old nursery plants of both species were transplanted in these pots. After two weeks of transplantation, water stress was continuously applied till the end of the experiment. After four months, data regarding shoot and root growth, nodulation, chlorophyll and relative water contents were determined following standard methods. Ionic composition (Na+, K+and Cl-) of shoot and root was determined by wet digestion. The results demonstrated that A. ampliceps was more tolerant to salinity due to better ionic composition and physiological attributes but when salinity was combined with water stress; its tolerance potential was decreased. On the other hand, A. nilotica performed better under water stress and when salinity was combined with water stress.