Abstract |
- Post-fire Pezizales often fruit seasonally approximately six weeks after a fire in successional groups over the course of two years. Two methods, pure culture synthesis and PCR-based identification, were used to determine if some of these species were mycorrhizal. Eleven fungal isolates, Anthracobia melaloma, Gyromitra infula, Helvella compressa, Morchella sp., Pseudorhizina calfornica, Rhizina undulata,
Sarcosphaera coronaria, Sphaerosporella brunnea, Trichophaea hem isphaeriodes,
Wilcoxina mikolae var. tetraspora, and an undescribed genus and species, were tested with two sugar levels (no dextrose and 5 g 1-1) for their ability to form myconhizae with two tree species (Douglas-fir and ponderosa pine) in an aseptic system for the pure culture synthesis experiment. Four fungi were included from the USDA Record of Decision. Containerized seedlings of Douglas-fir and ponderosa pine were grown for approximately four months. Only Wkoxina
mikolae var. tetraspora colonized the root tips. However, when colonizing ponderosa pine, ectendomycorrhizae were formed and on Douglas-fir, ectomycorrhizae were formed.
For the PCR-based identification study, post-fire Pezizales were examined for mycorrhizal formation with ponderosa pine in vivo on the Malheur National Forest. Fruiting bodies of post-fire Pezizales were collected from a prescribed burn site. Root tips were extracted from soil cores taken underneath fruiting bodies of post-fire Pezizales. Restriction fragment length polymorphisms (RFLPs) were compared between fruiting bodies and fungal symbionts on root tips. No matches were found; therefore, identities of these fungal symbionts were determined by DNA sequence analyses using the 18s, ITS 1, and 5.8s regions of the nuclear ribosomal DNA. The Pezizalean mycobionts were Geopora cooperi, Geopora sp.,
and Wilcoxina rehmii. Outcomes from both studies were inconclusive as to the mycorrhizal status of the post-fire Pezizales examined. Fungi that are probably not mycorrhizal include Helvella compressa, Scutellinia sp., Tricharina sp., the undescribed taxon, and species of Anthracobia, Morchella, and Peziza, found from burned areas. This study used PCR-based methods to determine the ascomycetous community in vivo. A database to help determine the ascomycete mycobionts was created.
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