The effect of salinity on anatomical characteristics of two halophyte species from Turkey
Anatomical adaptations of vegetative organs of Salicornia perennans Willd. and Suaeda prostrata Pall. subsp. prostrata distributed throughout the Kizilirmak Delta, Samsun were investigated in this study. To examine root, stem, and leaf anatomical modifications, the examined halophytic taxa were collected from the natural salt-affected soils of the study area. Some anatomical differences were detected in the roots, stems, and leaves of the taxa exposed to salinity. High salinity significantly increased the thickness of the periderm and cortex and the width of the aeriferous cavities in the root cortex of Salicornia perennans. The number of xylem vessels increased at higher salinity levels, whereas the diameters of xylem vessels decreased in the roots of Salicornia perennans. The diameters of xylem vessels decreased in the roots of Suaeda prostrata subsp. prostrata. Stem anatomical characteristics such as the thickness of the cuticle, palisade tissue, water-storing parenchyma, and the length and width of lignified cells, were increased by high salinity. Similarly, the thickness of the cortex in the stem of Suaeda prostrata subsp. prostrata was increased at the high salinity level. In addition, many tracheoblasts specific to Salicornia perennans were observed in the palisade tissue. In the leaves of Suaeda prostrata subsp. prostrata, the thickness of palisade tissue, and the succulence were significantly increased with a further increase in salt concentrations. Furthermore, stomata dimensions and stomata indices of both investigated taxa were considerably decreased under high salinity.