Water relations and drought-induced embolism in olive (Olea europaea) varieties 'Meski' and 'Chemlali' during severe drought

Abstract

We examined the effects of drought on the water relations, osmotic adjustment and xylem vulnerability to embolism of olive (Olea europaea L.) varieties, 'Meski' and 'Chemlali'. Two-year-old self-rooted cuttings growing in sand-filled pots in a greenhouse were subjected to water stress by withholding water for 60 days. Water relations and gas exchange measurements showed that 'Chemlali' was more drought resistant than 'Meski' and had a greater capacity for osmotic adjustment through solute accumulation. However, when water stress was acute, the effect of osmoregulation on leaf cell turgor was largely counteracted by xylem cavitation. Cavitation vulnerability curves showed that both varieties were highly resistant to embolism formation. The xylem water potential inducing 50% loss of stem conductivity approached -7 MPa in 'Meski' and only slightly less in 'Chemlali'. Although the difference between varieties in susceptibility to xylem embolism was small, it appears to account in large part for the difference between them in the ability to tolerate severe drought.

Re-introduction success of an autochthonous plant species, Periploca angustifolia, in the Natural Reserve of Oued Dekouk, Tunisia

“…Gas exchange parameters are well correlated with the plant's water status (Ennajeh et al, 2008). In the current study, in early spring (March), when environmental conditions were less stressful, spontaneous plants had higher g s and A than transplanted plants (Fig.…”

The Effect of Water Stress on Leaf Phenolic Composition, Fluorescence Parameters, Xylem Hydraulic Properties and Antiradical Activity of Four Tunisian Olive (Olea europaea L.) Cultivars

“…Chetoui and Meski cultivars differ greatly in their ability to withstand water stress. The cultivar 'Chetoui' is known for its drought tolerance, whereas 'Meski' is drought-sensitive [6,7]. But Ouslati and Jarboui cultivars despite their economic importance in Tunisia there isn't any information documenting their drought tolerance, our study can be considered as the first report on the physiological and biochemical parameters of these two cultivars under water stress.…”

Plant Water Status Indicators for Irrigation Scheduling Associated with Iso- and Anisohydric Behavior: Vine and Plum Trees

“…However, the simple criteria used here for irrigation scheduling would seem inadequate for the complex interpretation required when dealing with olive tree cultivars. According to Ennajeh et al [72], even if transpiration can also be significantly reduced under stress due to stomatal closure, Ψ l can be extremely low in relation to most other tree species as a result of the ability of olive trees to transfer water from tissues to the xylem sap.…”