Drought Tolerance Indices in some Olive Cultivars (Olea europaea L.)

Olive is a drought tolerant plant and there is considerable genetic variation for drought tolerance among olive cultivars. In order to evaluate genetic variation of olive, an investigation was carried out in factorial experiment based on completely randomized design with three replications on one-year-old of tewlve olive cultivars. Drought stress treatments included control, mild stress and severe stress (90, 55 and 35% of FC water, respectively). Results showed that drought stress reduced the relative water content and stomatal conductance in all cultivars. Dry biomass of root/shoot ratio, was increased by drought stress. Stress Tolerance Index (STI), Mean Productivity (MP), Geometric Mean Productivity (GMP), and Harmonic Mean (HARM) had the most correlation with relative growth percent in control and severe stress conditions, thus they were identified as the best indices for screening drought tolerant in seedlings of olive cultivars. Based on these indices and principal component analysis, cvs. Mission, Konservolia and Sevillano were detected as high tolerant cultivars to drought stress. Results of drough stress tolerance evaluation by drought stress indices obtained in the present study were highly consistent with other studies on traits of these cultivars.