Salt tolerant fungal endophytes alleviate the growth and yield of saline-affected wheat genotype PBW-343.

The purpose of this work was to assess how salt-tolerant wheat endophytic fungi promoted the growth of salt-sensitive wheat after inoculation. The endophytic fungal assemblages from salt-tolerant wheat genotypes (KRL-213, KRL-210 and KRL-19) and from salt-sensitive wheat genotype (PBW-343) were characterized, identified and determined for the current study. Of the fifty fungal isolates collected from both the salt-tolerant and the salt-sensitive wheat genotypes, 8 isolates recovered from salt-tolerant varieties were found to be resistant at high salt concentrations. These 8 isolates were characterized through several biochemical tests, such as plant growth promoting assay, extracellular enzymatic assay, carbohydrate utilization assay, antagonism versus plants pathogens and capacity to promote wheat seedlings (pot experiments). All tests revealed the positive results for 4 fungal strains (K13TR/150, K19TR/200, K-19TL/150 and K-19TL/200). These 4 fungi were identified as Aspergillus medius (K19TR/200), Cladosporium parahalotolerant (K13TR/150), Aspergillus versicolor (K19TL/150) and Aspergillus nishimurae (K19TL/200) through 18 S rDNA sequencing. Out of these, C. parahalotolerant and A. medius showed the synergistic effect with each other, so these 2 isolates were used in further experiments. These 2 isolates were involved in increasing the root-shoot length, proline and MDA contents. SEM and fluorescence microscopy were used to detect endophytic fungal colonization in the root of seedlings. C. parahalotolerant and A. medius heavily colonized the roots and it was noticed on the 21st day of the growth phase. These findings imply that fungal isolates have the potential to confer stress tolerance to their respective hosts and may enhance the agricultural production in the future, especially considering the changes in climate.