The investigating of sodium accumulation in some halophytic species of Zygophyllaceae, Polygonaceae, Asteraceae and Amaranthaceae

The identification of the characteristics of native halophytic species is very important for their practical application. The present study was carried out to identify the halophytic species of a desert and highly saline region around the city of Khosf, southern Khorasan Province, and to detect their general tolerance mechanisms (i.e. salt exclusion or inclusion). Sodium accumulation in the roots and shoots of seven species, including Launaea arborescens, Peganum harmala, Pteropyrum olivieri, Artemisia santolina, Zygophyllum eurypterum Boiss, Aerva javanica, Pulicaria gnaphalode, and their rhizosphere soil were determined. The bioconcentration of sodium from soil to roots (BCF), its translocation from roots to shoots (TF), and its accumulation in the shoots (AF) were then calculated. Results showed that the soil of the studied area was clay loam with a high EC of 65 ds/m, indicating its high salinity level. According to the values of sodium adsorption ratio (SAR) and the exchangeable sodium percentage (ESP) and regarding EC, the soil of studied region can be regarded as a saline-sodic soil. The value of TF in some species was higher than 1. However, none of the species had BCF and AF greater than 1, thus, none of them could be considered to be salt accumulator. Instead, it could be assumed that all of the studied species were salt, or at least, sodium excluders.