The Isolation, Identification and Characterization of Endophytes of Switchgrass (Panicum virgatum L.), a Bioenergy Crop

It has been established that perennial grasses harbour different types of endophytic bacteria and fungi. Switchgrass (Panicum vergatum L.) is identified as a model perennial energy crop. This study was conducted to explore fungal and bacterial endophyte communities inhabiting switchgrass cultivars of Quebec. The primary focus of this study was to isolate the endophytes, and provide taxonomic identifications based on comparative analysis of ITS rDNA gene sequences. A total of 145 endophytes isolates were recovered (52 bacteria and 93 fungi) from whole plant samples collected at early vegetative, and full reproductive stages. Five and nine different taxa of bacteria and fungi were identified, respectively. We evaluated the antagonistic activity of some endophytes against several fungal pathogens and selected candidate endophytes for future introduction into commercial switchgrass cultivars for biomass enhancement. We demonstrate the vertical transmission ability of some endophyte from one switchgrass generation to the next using species-specific primers. Artificial inoculation of young switchgrass seedlings with selected bacterial endophytes hold promise as a method of reinfection switchgrass seedlings.