The Endophytic Entomopathogenic Fungus Beauveria bassiana Alleviates Adverse Effects of Salt Stress in Potato Plants

The considerable decrease in crop productivity associated with the expansion of saline soils is an acute problem in agriculture. Endophytic fungi positively affect plant fitness under salinity conditions. The effects of potato inoculation with the conidia of the Beauveria bassiana strain Sar-31 on growth (the weight of fresh and dry biomass, shoot and root length, numbers of stolons and leaves, and the leaf surface) and physiological indices (the concentration of pigments, free proline and malondialdehyde, and antioxidant enzymes’ activity) were evaluated under moderate chloride salinity (100 mM). The results indicated that the plant’s association with the fungus mitigated the negative impact of salinity probably because of the activation of antioxidant enzymes and accumulation of free proline in potato tissues. Moreover, under the influence of B. bassiana Sar-31, the number of stolons significantly increased, which is one of the main characteristics of potato as an agricultural crop. Thus, Sar-31 may be a promising candidate for further investigation of its ability to stimulate growth and increase the stress tolerance of potato plants.