Search for fungal endophytes resistant to salt in order to extend the cultivation of medicinal plants in saline areas

Endophytes, especially fungal types, are often useful for host plants and while improving the production of specific metabolites of the host plant, they protect them against stresses, especially salt and drought stress. It is assumed that the plants that adapted to harsh conditions and lived in these climatic conditions for many years, are necessarily equipped with evolved salinity-resistant endophytes. Therefore, their isolation and transfering to host plants will provide the possibility of cultivation of medicinal plant in saline soil and drough conditions. For this purpose, Yazd province was considered as a pilot. In this study, different parts (root, stem and branches) of 112 species including ancient trees and prennials were selected. plant samples were transferred to the laboratory and after sterilization, were cultured in PDA. Out of 32 studied plant species, more than 70 endophytes were purified and cloned. Then, the isolated fungi were cultured in media with different salinity levels of 1, 2, and 3 M of sodium chloride NaCl, respectively. The results showed that among the investigated fungi, around 50 strains grew up in the medium containing one sodium chloride salt in 1M. In the continuation of the screening process of the selected samples, 6 strains of the isolated fungal endophytes were able to grow in the medium containing NaCl in the concentration of 3 M. The possibility of hosting the basil plant (Ocimum basilicum) for three selected endophyte isolates showed that all of the isolates have the ability to penetrate and spread in basil roots without any pathogenic symptoms. Study of the ITS genomic regions of ribosomal DNA of selected endophytes showed that there is a high sexual and species diversity in the isolated endophytes. The high biodiversity and the possibility of establishing selected endophytes in the basil plant in the current research will promise good results in basil cultivation in saline conditions, which requires further investigation.