DROUGHT TOLERANCE OF KNOTGRASS (POLYGONUM MARITIMUM L.) LEAVES UNDER DIFFERENT DROUGHT TREATMENTS

Abstract

Drought stress is a major environmental stress factor for plants causing significant adverse effects on crop growth and yield. Therefore, plant resistance against drought should be determined for wild plants to alleviate such impacts. Knotgrass (Polygonum maritimum L.) is a wild plant getting rarer every day in sandy coasts. The present study was consulted to determine the responses of knotgrass (Polygonum maritimum L.) to drought stress during vegetative growth stages. Plants were drought-stressed by withholding water for (72 hours) and (10 days). Relative water content did not change under drought stress, but the chlorophyll content decreased in both drought treatments. Although, superoxide dismutase (SOD) and catalase (CAT) activity increased more in 10 days drought treatment than 72 hours treatment, ascorbate peroxidase (APX) and glutathione reductase (GR) activity of the treatments were not significantly different. Moreover, both malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents did not change under drought treatments. Such findings indicated Polygonum maritimum as a tolerant species to drought stress during vegetative growth stages.