Effect of two species of mycorrhizal fungi on growth characteristics and essential oils of peppermint (Mentha piperita L.) under salt stress

In order to investigate the effect of two species of mycorrhizal fungi to reducing the salinity damage on peppermint (Mentha piperita L.), a pot experiment was carried out in research greenhouse of the Payame Noor University, Lorestan in 2017. The experiment was factorial based on a completely randomized design with three replications. The first factor included the planting bed (Mix two parts of the sand and a part of the soil) at 4 levels (sterile and non-sterile planting bed, and Sterile planting bed inoculated with Glomus mosseae and Glomus intraradices), and the second factor was salinity at three levels (0, 40 and 80 mM NaCl). After plant establishment, salinity treatments were applied at intervals four days for two months. Essential oil extraction was carried out using dried leaves in shade with hydrodistillation by the Clevenger, and essential oil content (%) and essential oil yield (ml per plant) were measured and calculated. The results of this study showed that with increasing salinity, plant growth characteristics such as plant height, stem diameter, the number of lateral shoots and leaves, leaf area, essential oil yield, and fresh and dry weight of leaf, stem, and root decreased, but essential oil content increased. Inoculation with both species of mycorrhizal fungi increased growth, shoot yield, essential oil content and yield in salinity conditions, so that, the essential oil yield in plants treated with G. mosseae and G. intraradices in 80 mM NaCl were 35.6 and 51.7 percent higher compared with control, respectively. Based on the results and considering the compatibility of mycorrhiza with the environment, the use of these fungi is recommended to reduce the destructive effects of salinity in peppermint.

Keywords:

Peppermint , Salinity , Sodium Chloride , Growth Characteristics , Essential Oil