Effect of salinity on growth, mineral composition, and water relations of grafted tomato plants

A greenhouse experiment was designed in order to evaluate growth, water relations, and nutrient concentrations of grafted and ungrafted tomato plants grown under varying levels of salinity (0, 30, or 60 mM NaCl). Two cultivars, 'Fanny' and 'Goldmar', were grafted onto AR-9704, using the cleft-grafting method. Growth of grafted 'Fanny' plants was higher than that of ungrafted plants. Growth of 'Goldmar' plants was not affected by salinity treatments or grafting, but it was slower than for 'Fanny'. Leaf turgor showed no significant differences between grafted and ungrafted plants or between salinity levels. The stomatal conductance (G(s)) was higher for grafted than for ungrafted plants, and salinity decreased it significantly and progressively in both grafted and ungrafted plants and in both varieties. The concentrations of Na+ and Cl- were significantly higher in ungrafted than in grafted 'Fanny' plants. 'Fanny' was more tolerant when grafted, probably due to reduced accumulation of Na+ and/or Cl- in the shoot.