evalvate salinity tolerance of salicornia at seed germination and vegetative growth stage under saline conditions.

The following experiments was conducted to evalvate salinity tolerance of 10 species of salicornia collected from the salt affected regions of Iran. Salt tolerance threshold was investigated at seed germination and vegetative growth stage under saline conditions. The present experiment is to screen 10 species of salicornia collected mainly from saline areas in Iran for salt tolerance at germination stage. A completely randomized block factorial experiment with three replications was carried out at 11 salinity levels (0, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 mol.m-3NaCl). Salicornia species were collected from various region( Fars, Azabaeijan, Boshehr, Esfahan and Karaj) of Iran dominated by saline soil. 25 seeds were germinated on 2 sheets filter paper moistened with 6 ml of solution treatments in 11 cm Petri dish under 12h dark/ light photo period in controlled environment at 250C. The seed percent germination and seed germination rates were reordered every days over 15 days after germination. There were significant species differences in the seed percent germination and germination rate .The genotype 17 and 2 showed higher percent germination and germination rate at 1000 mM NaCl. While the genotype 10 and 16 did not germination percent at 1000 mM NaCl. Experiment two was conducted in glasshouse using of species 17 at the levels of 0 up to 700 mol.m-3NaCl to determination of salt tolerance threshold. Fresh and dry weight of plant increased with an increase in salinity . Optimal growth of salicornia 17 at 200 mM NaCl were observed and growth declined with a further increase in salinity. Sodium content of plants increased when salinity was increased, but Ca2+, Mg2+ and K+ content of the plant was decreased. Succulence of shoot increase at low salinity and decreased at high salinity. Water potential of plants become more negative as the salinity was increase.