Effects of Salinity on Growth and Accumulation of Organic and Inorganic Ions in Cultivated and Wild Tomato Species

Abstract

The salt tolerances of a cultivated tomato ( Lycopersicon esculentum L. cv. Heinz 1350) and three wild species [ L. cheesmanii (Hook) C.H. Mull, L. peruvianum (L.), and L. pennellii (Cornell) D’Arcy] were determined in both sand and solution cultures. Curvilinear and two-piece linear methods were used to obtain response curves for fresh and dry weights of shoots. In solution cultures containing 0, 50, 100, and 150 mM added salt composed of 1:1 molar ratio of NaCl and CaCl 2 , ‘Heinz 1350’ was as salt-tolerant as any of the wild species. On the basis of relative decreases in vegetative dry weight, ecotype 1400 of L. cheesmanii was more sensitive to salt than ecotype 1401. After 4 weeks growth in sand cultures irrigated with nutrient solutions containing 0, 12.5, 25, 50, 75, and 100 mM added salts (5:1 molar ratios of NaCl and CaCl 2 ), L. pennellii had higher relative salt tolerance than the other species. After 14 weeks, the cultivated species and L. pennellii were more sensitive at low salinity than the other two species. However, relative yield decreases with increasing salinity were not significantly different between the cultivated tomato and the 1401 ecotype of L. cheesmanii at higher salt concentrations. L. peruvianum and L. pennellii accumulated less leaf Cl - and more leaf Na + than the other species. Significant differences in the partitioning of ions between mature and developing leaves were found for all species. The physiological mechanisms involved in tolerance at moderate salinities may differ from those required for survival at high salinity.