The dark septate endophytic fungus Phialocephala fortinii is a potential decomposer of soil organic compounds and a promoter of Asparagus officinalis growth

There is limited information as to whether dark septate endophytic (DSE) fungi are able to degrade organic carbon, nitrogen and phosphorus compounds in soil and if these fungi have a significant role in nutrient cycles in nature, especially under organic nutrient conditions. In order to further knowledge in this area, 25 DSE fungi were isolated and tested for their promotion of Asparagus officinalis seedling growth. Three Phialocephala fortinii isolates were found to be most effective in increasing the growth of A. officinalis plants compared with uninoculated controls. These isolates had the ability to degrade all carbon and nitrogen compounds tested except for lignin. Using organic phosphorus and nitrogen sources, the three P. fortinii isolates were able to promote the growth of A. officinalis compared with control plants. The isolates were also able to promote the growth of A. officinalis seedlings on semi-organic and organic media. Our findings demonstrate that P. fortinii has a role in the promotion of A. officinalis growth under organic nutrient conditions, possibly by decomposing organic phosphorus and nitrogen compounds in soil.