GROWTH, ION ACCUMULATION, AND LIPID-COMPOSITION OF 2 OLIVE GENOTYPES UNDER SALINITY

Olive (Olea europaea L cv. Leccino and cv. Frantoio) plants grown in a eroponic cultivation system were supplied with Hoagland solutions cont aining 0 and 150 mM NaCl for 4 weeks. Sodium (Na+), chloride (Cl-), an d potassium (Kf) concentration was measued on 15-day-old leaves and K/Na+ selectivity ratio was calculated. Plant water relations were esti mated on the same Leaves by measuring leaf bulk water and osmotic pote ntials, and by calculating leaf turgor pressure. Root and leaf tissues were also analysed for lipid composition, estimating free sterol (FS) , glycolipid (GL) and phospholipd (PL) content. The salt-sensitive Lec cino accumulated more Na+ and Cl- in the leaves and showed a lower K+/ Na+ selectivity ratio than the salt-tolerant Frantoio. The FS/PL ratio and the content of GL (namely monogalactosyldiglyceride, MGDG) in the roots were related to the salt accumulation in the shoot. Salinity-in duced changes on root lipids were more important in Frantoio than in L eccino, indicating the specific role of the roots in salt exclusion me chanisms. Conversely the effect of salinity on leaf lipid composition was more important in the leaves of the salt-sensitive Leccino.