COMPARATIVE SALT RESPONSES AT CELL AND WHOLE-PLANT LEVELS OF CULTIVATED AND WILD TOMATO SPECIES AND THEIR HYBRID

Response to increased salinity was compared in whole plants and calli from leaf, stem and root of Lycopersicon esculentum Mill. cv. P-73, Ly copersicon pennellii (Correll) D'Arcy ac PE-47 and their interspecific hybrid. Three NaCl treatments were applied (0, 70 and 140 mM) for 28 d. In both calli and whole plants, L. pennellii was more salt-tolerant than the cultivated species and the hybrid according to the growth re sponses, although different degrees of salt tolerance were generally f ound between plants and calli. The Na+ and Cl- accumulations with sali nity were higher in L. pennellii than in L. esculentum at both levels of organization. The interspecific hybrid showed an accumulation abili ty for Na+ and Cl- intermediate to its parents in the shoot of the who le plants and similar to L. pennellii in the callus tissues. Either no decrease or a small decrease of K+ concentrations with salinity were found in both whole plants and callus tissues of L. esculentum. Howeve r, K+ concentrations decreased in the organs and calli of L. pennellii and the hybrid with increasing salinity. Only at the whole plant leve l did L. pennellii have a Na+/K+ ratio higher than L. esculentum, show ing the hybrid to have values between those of its parents in the shoo t.