Abstract
Salicylic acid (SA) or orthohydroxybenzoic acid play a major role in regulation of many physiological processes e.g. growth, development, ion absorption and germination of plats. In order to evaluate the effects of prepriming Fennel seed with salicylic acid in salinity stress condition, on germination and growth characteristics of Fennel, an experiment was conducted in a factorial arrangement based on completely randomized design with three replications. The experimental treatments were salicylic acid with 7 levels (0, 0.1, 0.5, 1, 1.5, 2 and 4 mM) and salinity with 5 levels (0, 0.3, 0.5, 1 and 1.5 percentage). All salicylic acid and salinity treatments had significant effect on percentage and speed germination, length of radicle and hypocotyle, dry weight of radicle, hypocotyle and seedling and radicle / hypocotyle ratio (R/H). One mM salicylic acid had the highest percentage and speed of germination, length of radicle and hypocotyle and dry weight of radicle, hypocotyle and seedling. The highest radicle/hypocotyle ratio was obtained at 1.5 mM salicylic acid. Four mM salicylic acid didn't have significant effect on all maintained parameters. With no salinity stress (control), salicylic acid didn’t have any significant effect on all parameters, but when there was salinity stress; prepriming increased all studied characteristics significantly. Therefore, based on our results it seems that salinity resistance of Fennel seeds at germination stage will increase by treating seeds with on mM salicylic acid.

Keywords: Fennel, Germination, Orthohydroxybenzoic acid, Salinity stress