TORRES Myriam Mariela
congresos y reuniones científicas
Drought Stress during the Dry Winter-Spring Season affects Leaf-Level Biochemical and Physiological Parameters in Olives Trees
PIERLUIGI PIERANTOZZI; MARIELA TORRES; ROMINA BODOIRA; D. M. MAESTRI
Simposio; VII International Symposium on Olive Growing; 2012
INTA,CRILAR-CONICET,UNSJ, UNCuyo, UCCuyo, UNDec, CREA, Gobierno de San Juan
The aim of the work was to study the changes in some biochemical and physiological parameters in leaves from two olive varieties (Arbequina and Manzanilla) grown under different drought stress levels, applied during the dry winter ? spring season, in the olive cultivation area from central Argentina. Increasing levels of water deficit affected plant water relations as measured by pronounced drops of stem water potentials (near -4.0 MPa) in treatments with severe water deprivation. Deficit irrigation was associated with some leaf-level biochemical-physiological responses (accumulation of osmotically active substances, increased concentration of high molecular weight hydrocarbons and cuticle thickening), which can be interpreted as adaptation mechanisms of olive to water deficit. Water stress was also associated with increased malondialdehyde concentration, which is an indicator of membrane lipid peroxidation, and decreased levels of photosynthetic pigments. These responses followed a reversible pattern: the values from the mentioned parameters returned to baseline values after water deprivation suppression and rewatering. Water deficit affected both photosynthesis and leaf conductance in a similar way, suggesting that CO2 stomatal diffusion was the main factor affecting the photosynthetic rate. The results obtained may be useful for the evaluation of deficit irrigation strategies in semiarid environments with dry winter - spring period.