EFFECTS OF LIGHT AND SALINITY ON THE GERMINATION OF CLOSELY RELATED THREE SALSOLA TAXA

Abstract

Three closely related Salsola taxa (Salsola boissieri Botsch. subsp. serpentinicola (Freitag & Özhatay) Freitag & Uotila, Salsola boissieri Botsch. subsp. boissieri, Salsola turcica Yıldırımlı (halophytic ecotype), Salsola turcica Yıldırımlı (gypsicole ecotype)) from different edaphic conditions were studied according to changing light and salinity conditions. Seeds of target taxa were collected in 2017 and their weights were determined. The perianth segments were removed before the experimental trials and all the trials were conducted at 9°C/22°C which is the mean night and day temperatures of germination season. For the determination of the influence of light, one set of seeds for distilled water trial were kept at complete darkness. Different NaCl concentrations (distilled water, 100, 200, 300 mM NaCl) were used to evaluate the effects of salinity on germination. Viability of the seeds were determined by Triphenyl Tetrazolium Chloride (TTC) test which was applied to the seeds that did not germinate during the trials. As a result, it was found out that light stimulates germination of the taxa and Salsola seeds showed better germination ratio at light. The most tolerant taxa against salinity are the halophytic and gypsicole ecotypes of S. turcica, and the most susceptible one is S. boissieri subsp. serpentinicola. Both of the species show reduced germination ratios with increasing salinity. Salinity tolerance of S. boissieri subsp. serpentinicola and S. boissieri subsp. boissieri are very low, according to the Decreasing Germination Percentage (DGP) values. Although they show different germination response against increasing salinity, there is not any statistically meaningful difference between these three taxa according to germination percentages at different salinities, germination rates, last germination ratios and seed viabilities (F=1.818 p>0.05) (One Way ANOVA, SPSS 25).