COMPARATIVE RESPONSES OF “NABALI” OLIVE MICROSHOOT, CALLUS, AND SUSPENSION CELL CULTURES TO SALINITY AND WATER DEFICIT

Abstract

Comparative effects of in vitro-induced salinity and water deficit were studied in ‘Nabali’ olive (Olea europea) microshoot, callus, and cell suspension culture systems. Salinity and water deficit were induced by the incorporation of NaCl or sorbitol in the medium at 0.0, 25, 50, 75, 100, 125, or 150 mM. Induced salinity and water deficit significantly reduced (more negative) cell sap osmotic potential in the three tested culture systems. At the same treatment, the osmotic potential was less negative in the suspension cell and callus cultures compared to the microshoot cultures. On the other hand, induced salinity and water deficit significantly reduced shoot growth and rooting at treatments higher than 75 mM. Callus growth [width, fresh weight (FW), and dry weight (DW)], cell growth (FW and DW), and packed cell volume (PCV) were reduced with salinity or water deficit at concentrations more than 75 mM. When cultures from the three systems were subcultured to the control medium after being exposed to salinity or water deficit treatments, there were no differences in growth recovery or cell sap osmolarity compared with cultures always maintained in the control medium. This indicates the high capability of ‘Nabali’ olive to adjust itself to ambient environmental factors. We can conclude that cell suspension or callus culture system could be a sufficient alternative for the study of plant response and tolerance to salinity and water deficit in olive.