Determination of salt stress responses of OH×F 333 and OH×F 97 pear clone rootstocks in vitro and effects of silicon application

In this study, the responses of OH×F 333 and OH×F 97 pear clone rootstocks to salt stress and the effects of Si applications on reducing salt stress were investigated. For this purpose, two different experiments were conducted. In the first experiment, in vitro plants of OH×F 333 and OH×F 97 pear clone rootstocks were cultured in ½ MS medium containing gradually increasing different concentrations of salt (0, 50, 100, 150 and 200 mM NaCl). In the second experiment, Na2O7Si3 was added at 0.5, 1.0 and 2.0 mM concentrations in addition to the 100 mM NaCl concentration, where the plants were partially damaged, and the plants were incubated in these media for a total of 8 weeks. In Experiment 1, as the salt concentrations increased in vitro conditions, the regeneration rate and shoot number values decreased, while the degree of damage increased significantly. It was determined that most shoots lost their viability in 200 mM NaCl application. When the effects of different salt concentrations on biochemical parameters were examined, it was determined that total phenolic substance, total flavonoid substance, proline and soluble protein contents decreased, while lipid peroxidation content increased in parallel with salt concentrations. However, it was determined that there was an increase in the total phenolic and flavonoid substance contents in 150 mM NaCl application. In Experiment 2, it was determined that Si applications did not have a significant effect on eliminating the negative effects of salt stress. In Trial 2, while the total phenolic and total flavonoid contents increased in parallel with the increasing Si concentration in OH×F 333 rootstock, it decreased in OH×F 97 rootstock. While the lipid peroxidation content of both rootstocks decreased in parallel with the Si concentration, it was observed that the proline content increased relatively.