Fruit quality of grafted tomato plants grown under saline conditions

Tomato seedlings (cvs. 'Fanny' and 'Goldmar') were grafted onto the tomato rootstock hybrid AR-9704, using the cleft grafting method, and grown under greenhouse conditions. Tomato fruit yield and quality from plants exposed to 0, 30 or 60 mM NaCl, comparing grafted with ungrafted plants, was studied. Fruit yield was determined, and the chemical quality of fruit was analysed by measurements of sugars, lycopene, beta-carotene, ascorbic acid and mineral composition, and by determination of titratable acidity and soluble solids. Fruit yield was higher in grafted than in engrafted plants for both varieties, for 0, 30 and 60 mM NaCl. Salinity increased soluble solids, glucose and fructose, mainly at 60 mM NaCl, while ascorbic acid increased significantly only for grafted plants at 0 mM NaCl. The concentrations of beta-carotene and lycopene were not affected by salinity, but a large increase due to grafting was observed for all treatments. Sodium, chloride and nitrate ion concentrations were higher in ungrafted than in grafted plants, for the 60 mM NaCl treatment. Thus, grafting could be a useful tool to increase tomato fruit quality.