male gametophytic and sporophytic screening of olive cultivars for salt stress tolerance

pollen grains as well as whole plants of four olive (olea europaea l.) cultivars were screened for nacl salinity stress. different vegetative and physiological indexes of the cultivars were analyzed. leaf and root na/k ratio as well as stomatal resistance of plants exposed to salinity proved to be appropriate indexes of whole plant response to salt stress. whereas, in vitro pollen germination percentage served as a reliable index of pollen tolerance to salinity, pollen tube growth did not. a close correlation between pollen (gametophyte) and whole plant (sporophyte) responses to salinity was observed. these parallel responses imply that selection exerted at the gametophytic level could overcome breeding problems encountered at sporophytic level when dealing with adult olive plants.