Fungal Endophytes Promote Tomato Growth and Enhance Drought and Salt Tolerance

In a search for efficient fungal endophytes that can promote crop production and/or increase crop tolerance to abiotic stress, we isolated and tested various species harbored by wild plants. Sixty-seven endophytic fungal isolates were obtained from drought stressed, poor soil habitats, and inland high salt areas. We extensively tested the roles of <i>Ampelomyces</i> sp. and <i>Penicillium</i> sp. isolates in improving tomato growth and yield. Under greenhouse and field trails, <i>Ampelomyces</i> sp. and <i>Penicillium</i> sp. endophytes proved effective in conferring positive benefits to tomatoes placed under stress as well as under normal growing conditions. <i>Ampelomyces</i> sp. conferred tolerance to tomatoes placed under drought stress in addition to enhancing overall plant growth and fruit yield in comparison to non-symbiotic plants under drought stress. <i>Penicillium</i> sp. conferred tolerance to tomatoes placed under 300 mM salinity stress in addition to enhancing root biomass in comparison to non-symbiotic plants. Both endophytes proved efficient in enhancing plant growth, stress tolerance, recovery, and fruit yield under optimal experimental conditions in comparison to non-symbiotic plants. Field testing of tomato yield showed increased yield of symbiotic tomatoes compared to non-symbiotic ones. This data suggests that both <i>Ampelomyces</i> sp. and <i>Penicillium</i> sp. share a promising potential for improving future agricultural production, particularly with the projected changes in climate in the future.