Last week Stacia Hill collected cheatgrass tissue from three different sites on the ranch. The sites contained healthy plants and plants infected with the head smut pathogen Ustilago bullata. She surface sterilized shoots, roots and seeds of plants, and plated them on malt agar so the endophytes inside the tissue would grow out into the sterile growth medium. With help from intern Mariana Satterly, we isolated each individual fungal colony that grew out of the cheatgrass tissue. So far our collection of at least 300 endophyte isolates includes about 60 different fungal species.
Stacia Hill places surface sterilized cheatgrass on agar plates. (Photo by Lorinda Hunt)
We will use morphological characteristics of the fungal isolates as well as molecular methods to compare the endophytic communities that live inside healthy cheatgrass with those that live inside cheatgrass infected with Ustilago bullata. Endophytes unique to healthy cheatgrass plants could include antagonists that prevent Ustilago infection.
Brilliant colors produced by secondary metabolites infuse the clear agar under cheatgrass endophytes collected so far. (Photo by Mariana Satterly)