The most important black table olive (Olea europaea L.) “Kalamata" cultivar, grafted onto three different vegetative olive rootstocks[Picual (Pic), Frantoio (Fra) and Koroneiki (Kor) cvs.] was evaluated with 2-year-old grafted plants grown in sand clay soil, and received concentrations of salt mixture (NaCl, Na2So4, CaCl2, MgSo4 and KCl) making 6000 and 8000 ppm with SAR 12 of salinity level, for two seasons. Morphological and chemical parameters were investigated to determine the relative salinity tolerance of these rootstocks and to define possible reasons for any observed differences in the salt tolerance. However, results indicated that differences in response to salinity among rootstocks were observed primarily in morphological traits. Increasing of salinity level in irrigation water decreased, all of scion height and its rate of increase, leaf area, number of leaves/plant and fresh & dry weight of leaves and roots. But different rootstocks can affect the degree to which these pa-rameters is reduced under salinity, where Kalamata growth on Picual and Frantoio was considerably better than on Koroneiki at 6000 and 8000 ppm treatments. In-versely in untreated grafted plants Kalamata on Kornaki exhibited the best growth vigor, comparing with Kal/Pic or Kal/Fra plants, suggesting that a decrease of scion growth in untreated grafted plants is a salt tolerance quality transmitted by tolerant rootstocks. Salinity significantly decreased leaf chlorophyll (a) and (b) content of all grafted plants, but different content among rootstocks were noted. On the contrary, proline content increased in leaves of all treated plants, however, insignificant dif-ference was noted between rootstocks, yet the interaction between the two factors show that Kalamata on Picual and on Frantoio rootstocks recorded higher values of leaf proline content than Kalamata on Koroneiki rootstock. Leaves and roots Na+ and Cl- content of treated grafted plants showed an increment but to a different de-gree, comparing with the untreated (control) plants. There were differences among the grafted plants where Kalamata grafted on Koroneiki (the least tolerant cv.) most-ly affected by saline treatment and accumulated the highest content of Na+ and Cl- in leaves comparing with Kalamata on Picual (the most tolerant cv.) or on Frantoio (the Sanaa Laz
Arab Univ. J. Agric. Sci., 13(2), 2005
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moderate tolerant cv.). Tolerant rootstocks contained more Na+ in roots than in leaves. This response become apparent as salinity increased. Leaf N, P and K con-tents decreased in Kalamata leaves as influenced by different rootstocks and increas-ing salinity in irrigation water comparing with the control. Kal/Pic and Kal/Fra plants had higher N% in leaves than Kal/Kor plants, whereas Kal/Pic accumulated K more than the other plants, while P content in leaves of all grafted plants were insig-nificant in the two seasons. Based on the overall growth parameters and chemical composition in response to salinity, Kalamata grafted on Picual exhibited the great-est salt tolerance followed by those grafted on Frantoio whereas, Kalamata on Koro-neiki showed the poorest plants pertaining salt tolerance.