PHYSIOLOGICAL AND GENOTYPIC RESPONSES TO SALINITY IN TWO SPECIES OF TOMATO (LYCOPERSICON, SALT TOLERANCE, GENOTYPES)

Two species of tomato, Lycopersicon esculentum (domestic cultivars) and L. cheesmanii (wild types from the Galapagos Islands of Ecuador) were compared with respect to their tolerance of salinity. Chemical, biochemical, and physiological differences between selections of both species were used to evaluate the degree and variation in salt tolerance. The wild L. cheesmanii proved more salt tolerant than the domestic cultivars. This tolerance was based on the differences in absorption, translocation and compartmentation of sodium and potassium.;Several biochemical and physiological factors were involved in salt tolerance and the genetic components were complex and interrelated.;The conclusions drawn from these studies were: (1) Genetic variability with regard to salt tolerance exists between the two species. (2) The physiological manifestation of that variability is the ability of the wild type to absorb and tolerate sodium in the leaf tissue. (3) The genetic information that codes for the physiological adaptations for tolerating salinity can be transferred from the wild type to the domestic cultivar.;The variation in salinity tolerance was found to be under genetic control. Interspecific genetic crosses between the salt tolerant wild type, and domestic cultivar were used to demonstrate the heritability of salinity tolerance.