Evaluation of Some Morphological, Physiological and Biochemical Traits of Ancient Syrian Olive Dan (Olea europaea L. Var. Europaea Dan) for Drought Stress Response

Abstract

Drought is one of the most critical global problems that threaten agricultural production in the recent years. Various plants were classified as drought-tolerant, including olive tree. This study focused on evaluating variations in drought-stress response of local perennial olive Dan (Olea europaea L. Var. Europaea Dan), by studying samples of the same cultivar Dan but from two different climatic zones; Hawt region, a dry zone in the south of As-Suwayda, and Ambiya-Qatana region, an humid zone in the west of Damascus in Syria. Several morphological parameters were measured including the average length of the fruity branches and the average of leaf area, the relative water content and dry matter percentage are determined, and proline concentration in olive leaves was measured. The results showed significant variations in the average length of fruity branches and the average real leaf area in the humid-zone trees (51.48 cm, 161.33 cm², respectively), which were higher than in the dry-zone trees (38.78 cm, 138.91 cm²). The results did not show any significant variation for the average of dry matter ratio of leaves which was relatively higher in Hawt region (%59.65 ± 2.6) than that in Ambiya region (%58.27 ± 1.54), while the average relative water content of leaves in trees of Ambiya humid zone (76.88%) was significantly higher than that in trees of Hawt dry zone (66.34%). Proline content average in leaves of dry region trees (0.52 mg/g FW) was significantly higher than those in Ambiya region trees (0.34 mg/g FW).