Characterization of Root-Associated Fungal Endophytes of Bioenergygrass Freedom Giant Miscanthus.

Giant Miscanthus is a considered one of the top bioenergygrass that can be cultivated to meet the annual biomass production by 2030 to fulfil the U.S. bioenergy vision for energy independence. Freedom Giant Miscanthus (FGM) is a commercial variety that is drought and heat tolerant with expected stand life of 20 years. From an ecological perspective, the long-term and large-scale production of energygrass necessitates investigations into their microbial communities since microbial endophytes are thought to impact plant growth and productivity similarly to human gut microbes which are known to influence human health and well-being. The overall objective of this study was to isolate root-colonizing fungal endophytes of FGM and develop a fungal culture collection unique to FGM, and characterize their attributes along the mutualism-parasitism continuum. FGM root samples were collected in spring 2017 from two plots in Lorman, Mississippi. The FGM the crop has been cultivated since 2013 without any fertilization or weed control under rain-fed conditions. The fungal endophytes were isolated on at least eight selective media. A variety of fungal species with putative mutualistic roles (Periconia macrospinosa, Trichoderma), neutral (Microdochium) and parasitic/pathogenic roles (Fusarium, Curvularia) were isolated. Ongoing growth-chamber experiments of FGM symbiosis with the fungal isolates will confirm the endophytic status along the mutualism-parasitism continuum. Periconia macrospinosa and Microdochium sp. are known dark septate endophytes (DSE) in other native C4 grasses, and isolates from FGM have also shown to be DSE fungi. Spring 2017 isolations provided about 30 fungal isolates and data from similar collection from summer 2017 will also be presented. Furthermore, isolates from two other geographical locations will be included. In the future, the overall FGM microbial culture collection could be used in toto in specific combinations for manipulating FGM health and productivity.