The influence of seeds inoculation with Plant Growth Promoting Rhizobactria (PGPR) on some germination, biochemical indices and content of some elements in fennel (Foeniculum vulgare L.) under salinity stress

Regarding the development of medicinal plants cultivation and the increase of saline lands, as well as the increasing importance of using biological fertilizers in order to achieve sustainable agriculture, the present study was conducted to investigate the response of germination and biochemical indices of fennel to inoculation with growth promoting rhizobacteria under salt stress conditions. This experiment was conducted as a factorial based on two factors in a completely randomized design with four replications by inoculating seeds with bacteria in 5 levels (PF2, PF56 of Pseudomonas fluorescent, Bacillus subtilis, Azotobacter sp. and non-inoculation) salinity stress in three levels (0, -4 and -8 bar imposed by NaCl) at laboratory of agriculture faculty of Yasouj University in 2015. The results showed that salinity stress decreased soluble protein content, ascorbate peroxidase enzyme activity, P content, K content, germination percentage, weight and length vigors, and increased Na content and Na/K ratio. In all three levels of salinity stress, the highest and lowest germination percentage was obtained from seeds inoculated with PF2 strain and non-inoculated seeds, respectively. In salinity level of -8 bar, the highest soluble protein content (0.841 mM. g-1 FW) and the least ratio Na/K (0.674 %) was obtained from PF2 strain and also lowest soluble protein content (0.0531 mM. g-1 FW) and the highest Na/K ratio (1/081) was related to control (0bar) treatment. In general, biological treatments were effective in improving germination and increasing the activity of antioxidant enzymes under salinity stress conditions in fennel.