Soumaya Dbara - Regional Research Centre in Horticulture and Organic Agriculture, IRESA-University of Sousse, BP۵۷ Chott-Mariem ۴۰۴۲, Tunisia
Wafa Boussetta - Olive Tree Institute, ۴۰ Ibn Khaldoun street, ۴۰۶۱ Sousse, Tunisia
Mariem Hafi - Olive Tree Institute, ۴۰ Ibn Khaldoun street, ۴۰۶۱ Sousse, Tunisia
Messaoud Mars - UR Agrobiodiversity (UR۱۳AGR۰۵), Higher Agronomic Institute of Chott-Mariem, ۴۰۴۲, IRESA-University of Sousse, Tunisia

Purpose: The evaluation of the response of three old pear cultivars (’Meski Arteb’, ‘Bouguedma’ and ‘Alexandrine’) to drought was performed through some physiological traits and leaf characteristics. This work aimed to highlight the behavior of these cultivars under water stress conditions. Research method: The experiment was carried out in a greenhouse under controlled conditions by the application of three water stress levels as a complete randomized block. Plants showed moderate water deficit after ۱۰ days without watering and severe stress after ۲۰ days without watering. Control plants were kept well watered. Findings: Data showed a similar cultivar response to water stress but with various degrees. The relative water content and the water potential of leaves decreased with the water stress severity in all cultivars. Stomatal conductance and photosynthetic assimilation followed the same path with water status parameters, and ‘Alexandrine’ showed the highest level of gas exchange parameters. Chlorophyll content and total soluble sugars concentration of leaves decreased in response to drought increase. However, the proline content and leaf characteristics were unaffected except for ‘Bouguedma’ cultivar for which leaf area and succulence were reduced under severe stress. Limitations: No limitations were founded. Originality/Value: the three cultivars behaved differently against drought, these traits can be exploited for further breeding programs to face climate change impact.

Drought, Gas exchange, Leaf, Pear, Physiology