Ecophysiological effects of mycorrhizal applications on some medicinal plants grown in heavy metal contaminated soils

Effects of Rhizophagus intraradices applications were observed on plant nutrition, growth and stress response in Linum usitatissimum and Salvia fruticosa under the heavy metal stress. The research was carried out on two factors by planning according to the 'randomized design' on Linum usitatissimum and Salvia fruticosa plants. One of the factors is two different mycorrhiza applications (mycorrhizal and non-mycorrhizal and the other heavy metal application at different levels. Germinated seeds were sown into trays, and then they were transfered into plastic pots. When the plants were two months old, Cd and Zn stress treatments were started. Heavy metal traetment concentrations were determined according to their toxic concentrations. Ingestad nutrient solution was used in the control groups. 60µM Cd (3CdSO4.8H2O) and 700 µM Zn (ZnSO4.7H2O) concentrations were prepared in the Ingestad solution for the metal treatment groups. Plants were watered with these treatment groups and then they were harvested at the end of the 21th day. In our results, the amount of Ca element of control group and Fe element of Zn group decreased in the soil where Linum usitatissimum plant was grown. Mycorrhiza effectively infected plant roots Mycorrhiza application in the soil where Salvia fruticosa plant is grown does not cause any change in the amounts of Mg, K, Ca, Fe, Cu, Mn elements. Metal stress were not affected the results of the percentage of colonization in the roots of both plants. In other words, AM symbiosis eliminated the negative effect of heavy metal stress or completely colonization occurred in the roots before heavy metal stress application and stress could not prevent colonization. Due to our plant ICP-OES results it is thought that Linum usitatissimum retains the Cd element in its roots approximately 4 times more with mycorrhiza application, in other words, this plant may be a root accumulator. In Salvia fruticosa, it is seen that mycorrhizal applications reduce the amount of Cd in the root, but increase the amount in the stem and leaves. While mycorrhiza application alone decreased root and stem length in Linum usitatissimum, root length increased with mycorrhiza applications in Zn and Cd groups. In Salvia fruticosa, mycorrhiza application increased root and stem length in control and Zn groups. It was determined that the dry weight of leaves in Linum usitatissimum (in control and Cd groups) was slightly higher in plants with mycorrhiza than in plants without mycorrhiza, the dry weight of leaves in Salvia fruticosa (in Zn and Cd groups) was slightly higher in plants with mycorrhiza than in plants without mycorrhiza. Mycorrhiza applications decreased root dry weight in Linum usitatissimum ( in Zn group) and Salvia fruticosa (in control and Cd groups). In Linum usitatissimum, the amount of proline was increased in the Zn and Cd groups (Non-mycorrhiza applications) compared to the control. In Salvia fruticosa, on the other hand, it was observed that different applications did not make a significant difference on the amount of proline. Total phenolic content of Linum usitatissimum decreased with mycorrhiza application in the control group. In Zn and Cd groups, mycorrhiza applications caused an increase in the total phenolic content in the leaves. In Salvia fruticosa, the total phenolic content of the control group increased in the stem with mycorrhiza application and decreased in the leaf. Zn and Cd applications also decreased the total phenolic content in the leaf. Mycorrhiza application increased the total chlorophyll content of the Zn treated Linum usitatissimum, however it caused a decrease in Salvia fruticosa.