Influence of arbuscular mycorrhizae and plant growth promoting rhizobacteria on proline, membrane permeability and growth of strawberry (Fragaria x ananassa) under salt stress

Salinity is one of the most important factors negatively effecting the yield in crop species. In this study the effect of plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizae on proline content, membrane permeability and growth of strawberry cv. 'San Andreas' were studied under different salt treatments (0, 30 and 60 mM/L NaCl). The leaf area was measured 0, 15, 30, 45 and 60 days after saline solution applications on the plants. The results showed that increasing concentrations of NaCl decreased all growth parameters. Increased salt concentration led to increased proline level compared to the control. Bacterial application at 60 mM/L NaCl concentration provided the highest ameliorative effect and therefore determined the most effective protection of the plant against salt stress. It was observed that the anthocyanin content increased in line with the increasing salt concentration. In general, the salt applied on the plants causes an increase in membrane permeability and thus disrupts membrane stability and becomes a significant factor damaging the plant. Membrane permeability increased at applications with 30 mM/L and 60 mM/L NaCl. Our results revealed that bacteria application can have an ameliorative effect that helps the plant to tolerate the negative effects of salt stress by increasing proline and anthocyanin levels