Evaluation of Morphophysiological Response of Teucrium polium L. to Drought Stress

Among the environmental barriers to plant growth and yield, drought, an icon of arid and semi-arid regions is the most important factor in reducing production. Teucrium polium L. is one of the most important medicinal plants of the family Lamiaceae that exists in these areas. In order to study the effect of drought stress on some physiological and morphological traits of Teucrium polium L., an experiment based on randomized completely design was conducted with three replications at Research Greenhouse of Natural resources College of yazd. Water deficit levels included100% field capacity as the control, 75% field capacity (mild stress), 50% field capacity (medium stress) and 25% field capacity (severe stress). The results showed that the branches height per plant with (100.48 cm), fresh and dry weight of stem with (5.7 and 2.3 g) and  concentrations of Nitrogen, Phosphorus and Potassium in aerial with (3.58, 0.45 and 2.7%) in 75% field capacity treatment was observed. Also, with increasing drought stress level (medium stress) chlorophyll a, chlorophyll b and total chlorophyll content were increased. The most level of forementioned factors was observed at 50% of field capacity treatment with 7.3,21.5,6.2 27.6 mg / g, respectively. further water deficit (25% crop treatment) showed that the concentration of these pigments decreased. On the whole the experiment results showed relative tolerance of Teucrium polium L. to drought stress. Therefore, for better establishment of this plant in the fields it is better to transfer the seedlings to the pasture either by rooting the cuttings of the plant under greenhouse conditions or by planting seeds for one year in the greenhouse.