Current Journal of Applied Science and Technology

Any change in climatic conditions affects growth and productivity directly or indirectly. The present study was carried out to investigate the impact of varying climatic conditions of Tabuk region of Saudi Arabia on the performance of Teucrium polium plants. Plants were collected under varying environmental conditions of February, May, August and November 2014. Performance of the plants was assessed in terms of fresh weight (FW) and dry weight (DW), leaf chlorophyll content (Chl), carbonic anhydrase (CA) activity, hydrogen peroxide (H₂O₂) content, leaf relative water content (LRWC), activites of antioxidant enzymes viz. superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) and leaf protein content. The results show that plants collected during August gave lower values for all the studied parameters except H₂O₂ content which was highest. Therefore, climatic conditions of November were found most suitable for proper growth and development of plants, as exhibited by higher values of most of the parameters except H₂O₂ content which gave lowest values during November. Plants sampled during November gave 24.8%, 61.8%, 48.1% and 12.0% higher values for FW, DW, total Chl content and activity of CA enzyme, respectively, than the plants collected during August which gave lowest values for these parameters. Moreover, plants collected during November again gave 0.5%, 66.4%, 34.6% and 53.3% higher values for SOD, CAT and POX and leaf protein content, respectively, than the plants collected during August. Thus, the present study suggested that the climatic conditions of Tabuk region during November suited best for the growth and development of Teucrium polium plants.