Interactive effects of Ca superior 2 superior + and NaCl salinity on the growth of two tomato genotypes differing in Ca superior 2 superior + use efficiency

摘要

Two tomato (Lycopersicon esculentum Mill.) lines differing in Ca superior 2 superior + use efficiency (Ca superior 2 superior + use efficient line 113 and Ca superior 2 superior + use inefficient line 67) were subjected to salinity treatments in two separate experiments to determine whether they differed in salt tolerance. In experiment I, three NaCl and two CaCl inferior 2 treatments were imposed. The Na superior + concentrations were 1.1, 100 and 150 mM and the Ca superior 2 superior + concentrations were either 1.51 or 10 mM. In experiment II, one NaCl and three Ca superior 2 superior + treatments (as CaCl inferior 2 or CaSO inferior 4) were imposed. The treatments consisted of 150 mM NaCl at either 1.51 mM CaCl inferior 2, 10 mM CaCl inferior 2, or 10 mM CaSO inferior 4. Response to treatments was determined by analysis of growth parameters (shoot and root dry weights, plant height, and root length). Shoot and root dry weight, and root length were depressed as salinity increased it plants lacking additional Ca superior 2 superior +. No significant differences in salt tolerance were detected between the two tomato lines after 24 d of salinity treatment. An important finding of this study was that root growth and length appeared to be more sensitive to the effect of CaCl inferior 2 treatment alone and to the effects of CaCl inferior 2 x NaCl treatments. This suggests that over the long term, both root growth and root length may be more sensitive indicators of salinity effects than shoots. Supplemental CaCl inferior 2 had no ameliorative effect on NaCl stress in shoot growth. The inability of Ca superior 2 superior + to counter Cl superior - entry or toxicity may account for the lack of amelioration. Additional Ca superior 2 superior + as CaSO inferior 4 improved shoot growth of plants exposed to 150 mM NaCl. In contrast, root growth and length were improved by 10 mM Ca superior 2 superior + as either CaCl inferior 2 or CaSO inferior 4.