EVALUATION OF SALT TOLERANCE IN CULTIVATED AND WILD TOMATO SPECIES THROUGH IN-VITRO SHOOT APEX CULTURE

The possibility of using in vitro shoot apex culture to evaluate salt tolerance of cultivated (Lycopersicon esculentum Mill.) and wild (Lyco persicon pennellii (Correll) D'Arcy) tomato species was determined and related to the response obtained by callus culture. Both apices and c alluses were grown on media supplemented with 0, 35, 70, 105, 140, 175 and 210 mM NaCl, and growth and physiological traits were determined. Most apices of L. esculentum did not develop roots from low NaCl leve ls, whereas the apices of L. pennellii were able to develop roots at t he different salt levels. This different degree of salt tolerance betw een L. esculentum and L. pennellii was not, however, clearly shown on the basis of the shoot growth of the plantlets. The callus response wa s similar to that shown by the rooting parameters, as callus growth in response to increased salinity was much greater in L. pennellii than in the tomato cultivar. K+ decreased more and proline accumulated less with salinity in shoots of L. esculentum compared to L. pennellii, wh ereas the opposite response was obtained in calluses. The results obta ined in this study suggest that rooting parameters are the most useful traits for rapid evaluation and screening of tomato species and segre gating populations through in vitro shoot apex culture.