This study aim at investigating the tolerance of two tomato rootstock (Sprit and ES-
30502) widely speared in Syria and used for crafting some tomato hybrids grown in green
houses for different salinity levels (0- 25- 50- 75- 100- 150 mM NaCl).
Th
e results show that the germination of rootstock Sprit seeds was not influenced by
high salinity 150 mM despite a delay of 1-2 days compared with the control. A reduction
of 15% was observed in the rootstock ES-30502 at 100 and 150 mM NaCl salinity levels,
in addition to slower percentage rate of germination. In contrast, the effect of salinity on
the development of the radical and rootlet was more pronounced in Sprit compared to ES-
30502. Salinity decreased the growth of both shoots and roots, and also decreased nutrient
acquisition in both rootstocks, but to a lesser degree in ES-30502. The uptake of K was not
greatly affected and concentrations in shoot remained normal. The concentrations of Ca
and Mg were also not affected by salinity. The most pronounced effect of salinity was on
nitrogen effect (NO3) which was reduced greatly in both rootstocks. This was accompanied
by accumulation of free NO3 ions in the shoot tissue (58 and 45 % of total N uptake at
salinity level of 150 mM). It is most likely that toxicity of Na and Cl ions, and consequent
osmotic changes in cell tissue led to slower nitrate reductase activity (NRA) and
accumulation of NO3.
