Determination of tolerance levels of myrtle (Myrtus communis L.) genotyps to salt stress in in vitro conditions

In this study, the response of 2 myrtle genotypes (Asımersin and Tatlımersin) to salt stress at different concentrations in in vitro conditions was investigated in terms of the morphological and biochemical characteristics. In the experiment, 1-1.5 cm long micro shoots were planted in MS nutrient media containing different salt concentrations (0, 50, 100, 150 and 200 mM NaCl) and were incubated for 8 weeks. At the end of the incubation period, regeneration rates, number and length of shoots, mineral substance contents (P, K, Ca, Mg, Fe, Zn, B, Na, Mn, Cu), total phenolic and proline were determined. In Experiment I, which uses MS media containing direct NaCl, it was determined that all plants died in media containing 200 mM NaCl. Aşımersin and Tatlımersin genotypes in media containing 150 mM NaCl were died 96.7% and 93.4% of the plants, respectively. In Experiment I, it was determined that the shoot length was higher in 50 mM NaCl application than the control application. In Experiment II, where NaCl concentrations were gradually increased, partial plant deaths occurred in 100, 150 and 200 mM NaCl applications. In Experiment II, as the NaCl concentration was increased, proline amounts increased, and the total phenolic contents decreased. As the NaCl concentration in the nutrient media increased, there was a decrease in Zn, Mg, K, Ca, Mn and Cu intake of plants and an increase in Fe, P and Na intake. There was no significant difference between genotypes in terms of plant development. Higher values were found in the genotype of Tatlımersin (with black fruit) in the content of proline and in the genotype of Aşımersin (with white fruit) in terms of the total amount of phenolic substances. Intake of Mg, B, Ca and Mn from mineral substances was found higher in the Tatlımersin genotype, P intake was higher in the Asimersin genotype, but no difference was found between the genotypes in terms of Zn, Fe, Na, K and Cu.