Effects Of Varying Salinity On Leaf Ultrastructure Of Potamogeton Pectinatus L

Abstract Potamogeton pectinatus is a submerged halophyte which occurs in waters of low salinity (5% to 10%). Its upper salinity tolerance has been reported to be 19%. Reasons why P.pectinatus is unable to tolerate salinities in excess of 19%is important to our understanding of its biology. In the present study, leaf ultrastructure of plants growing at low salinity was compared with plants growing at high salinity in order to assess the effects of different salinities on the ultrastructure. Attention was focussed on ultrastructural changes occurring in the leaf epidermis, the main photosynthetic tissue. Plants were grown in seawater at two salinities : 5%(low salinity) and 20% (high salinity). Pieces of mature leaf blades from both treatments were harvested and prepared for Transmission Electron Microscopy (TEM) following standard procedures. The overall distribution and concentration of chlorine (CI) in the leaves was ascertained since this element is the most abundant anion in seawater and is important in considerations of salt tolerance in submerged halophytes.