Drought stress during the dry winter-spring season affects leaf-level biochemical and physiological parameters in olives trees

PIERLUIGI PIERTANTOZZI; MARIELA TORRES; BODOIRA ROMINA; DAMIÁN MAESTRI

San Juan

Simposio; VII International Symposium of Olive Growing; 2012

Instituto Nacional de Tecnología Agropecuaria. Universidad Nacional de San Juan. CRILAR-CONICET. CREA. Universidad Nacional de Cuyo

The aim of the work was to studythe changes in some biochemical and physiological parameters in leaves from twoolive varieties (Arbequina and Manzanilla) grown under different drought stresslevels, applied during the dry winter ? spring season, in the olive cultivationarea from central Argentina. Increasing levels of water deficit affected plantwater relations as measured by pronounced drops of stem water potentials (near -4.0 MPa) in treatments with severe waterdeprivation. Deficit irrigation was associated with some leaf-levelbiochemical-physiological responses (accumulation of osmotically activesubstances, increased concentration of high molecular weight hydrocarbons andcuticle thickening), which can be interpreted as adaptation mechanisms of oliveto water deficit. Water stress was also associated with increasedmalondialdehyde concentration, which is an indicator of membrane lipidperoxidation, and decreased levels of photosynthetic pigments. These responsesfollowed a reversible pattern: the values from the mentioned parametersreturned to baseline values after water deprivation suppression and rewatering.Water deficit affected both photosynthesis and leaf conductance in a similarway, suggesting that CO2 stomatal diffusion was the main factoraffecting the photosynthetic rate. The results obtained may be useful for theevaluation of deficit irrigation strategies in semiarid environments with drywinter - spring period.