Salinity Tolerance and Ion Accumulation of Coastal and Inland Accessions of Clonal Climbing Plant Species Calystegia sepium in Comparison with a Coastal-Specific Clonal Species Calystegia soldanella

Abstract

Plant species adapted to saline habitats represent an important resource in the assessment of salinity tolerance mechanisms. The aim of the present study was to analyze salinity tolerance and ion accumulation characteristics for various accessions of Calystegia sepium from different habitats in comparison to these of Calystegia soldanella in controlled conditions. Plants were introduced in culture using stem explants with leaf and were cultivated in controlled conditions under six different substrate salinities. Salinity tolerance of both C. sepium and C. soldanella plants was relatively high, but the tolerance of particular accessions did not depend on the substrate salinity level in their natural habitats. C. sepium accession from a mesophytic non-saline habitat was only slightly negatively affected by increasing substrate salinity. However, coastal accession of C. sepium and coastal-specific species C. soldanella had some similarities in ion accumulation characteristics, both accumulating a high concentration of soluble ions in aboveground parts and excluding them from underground parts. All C. sepium accessions from different habitats represented varied physiotypes, possibly associated with their genetic differences. C. sepium accessions from different habitats can be suggested as models for further studies aiming at dissecting possible genetic, epigenetic and physiological mechanisms of adaptation to heterogeneous environmental conditions.