Effects of NaCl on germination and initial growth of local trees, Samar(Acacia tortilis), Ghaf(Prosopis cineraria), Sidr(Zizyphus spina-christi)and Markh(Leptadenia pyrotechnica)widely used for revegetation of desert in The United Arab Emirates were investigated.
Germination was tested at the different NaCl concentrations(30, 60, 90, 120mM). Initial growth of seedlings was examined in the solution culture added with the different NaCl concentrations (60, 120, 180mM). Non-added NaCl concentrations were set as the control in both experiments.
The results are as follows:
1.Germination rate at 120mM NaCl concentration to the control was in order of Ghaf(80)>Samar(77)>Markh(67)>Sidr(28).
2.Height and dry matter weight of top of the seedlings decreased with the rise of NaCl concentrations. As a result, obvious growth inhibitions were observed except in Ghaf.
3.The decrease of dry matter weight of top of the seedlings was in order of Ghaf (72)>Sidr(51)>Samar(21)>Markh(11)under 180mM NaCl concentration.It is considered that Ghaf and Sidr have markedly higher tolerance to the salinity comparing with Samar and Markh.
4.Ghaf was the most tolerant to the salinity in both germination and initial growth.However, the tolerance to the salinity in initial growth of seedlings differed from those in germination among Samar, Sidr and Markh.
The difference of tolerance to the salinity among the species was discussed from the viewpoint of mineral elements uptaken in each part of the seedlings.

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