Anatomical Adaptations to Salinity in Spergularia marina (Caryophyllaceae) from Turkey

The present paper deals with the salt effect on root, stem and leaf anatomy of Spergularia marina . Salt tolerant populations of Spergularia marina from low (2.0–4.2 dS/m), medium (9.3–10.7 dS/m) and highly (18.4–26.2 dS/m) saline soils were evaluated for anatomical modifications. Root anatomical characteristics as cortex thickness and xylem vessel diameter were decreased in high saline environments. Increased aerenchyma and periderm thickness in the root were critical for checking water loss and enhancing water storage capability. In stem, higher salinity decreased the thickness of the epidermis and cortex. Increased aerenchyma and increased thickness of vascular tissue seemed to be crucial for its better survival under saline environments. The thickness of sclerenchyma was unchanged under low and moderate salinity but considerably increased under high salinity. Leaf anatomy shows that salt stress resulted in an increase of cuticle and parenchyma thickness as well as an increase of vascular bundle sheath thickness. The presence of the cells with calcium oxalate crystals in the stem and leaf increased at higher salinity. Additionally, under high salinity it was observed that both stomatal index and stomatal dimensions were considerably reduced. These results show that salinity stress shows significant anatomical modifications in Spergularia marina .