Table 2.
SSCP analysis of fungi associated with C. austinae and surrounding tree ECM
| California county/sample | Fungi in orchid | Zygosity | Thelephoroid ECM fungi on adjacent tree roots | Zygosity | Other ECM fungi on adjacent tree roots |
|---|---|---|---|---|---|
| Tehama 1 | Thelephoraceae 2 | hm | Thelephoraceae 2 (1) | hm | Russula + 2 |
| Tuolumne 1 | Thelephoraceae 8 | hm | Thelephoraceae 8 | het | Lactarius, Russula + 3 |
| 2 | Thelephoraceae 7 | het | Thelephoraceae 7 | het | 1 |
| Humboldt 1 | Thelephoraceae 1 | het | Thelephoraceae 1 | het | 0 |
| 2 | Thelephoraceae 11 | het | Thelephoraceae 11 | het | 3 |
| Monterey 1 | Thelephoraceae 12; Thelephoraceae 13 | hm | Thelephoraceae 13 (2) | hm | 4 |
| Trinity 1 | Thelephoraceae 7 | het | Thelephoraceae 7 (1) | het | 3 |
| 2 | Thelephoraceae 8 | hm | Thelephoraceae 8 | hm | 3 |
| El Dorado 1 | Thelephoraceae 7 | het | Thelephoraceae 7 | het | 3 |
| 2 | Thelephoraceae 7 | het | Thelephoraceae 7 | het | 5 |
| 3 | Thelephoraceae 7 | hm | Thelephoraceae 7 (1) | hm | 2 |
The Thelephoroid fungi that associate internally with C. austinae simultaneously form ECM on photosynthetic hosts in nature. Each row shows the fungal ITS–RFLP type of the fungi found in orchid roots and the type found in Thelephoroid fungi forming ECM on photosynthetic tree roots from a single 10-cm diameter soil core. Other Thelephoroid species, in addition to those associated with the orchid, often formed ECM, which were recovered from the same soil cores; numbers of these are given in parentheses. RFLPs also were generated from ECM that did not have Thelephoroid morphologies to estimate the diversity of ECM-forming Basidiomycetes present at each site. However, no attempt was made to identify these non-Thelephoroid fungi except in the case of several types known to belong to the Russulaceae. In addition to RFLP analysis, the ITS region amplified from Thelephoroid fungi on orchid and tree roots was compared by single-strand conformational polymorphism analysis. The migration patterns were different for each distinct RFLP type but were identical in orchid/tree pairs from each soil core except in one case, in which two bands migrated identically, but the ectomycorrhizal sample had two additional bands. However, ECM from other cores had the same two band patterns as the orchid in this core. Therefore, all of the orchid fungi were shown to form ECM as well. In general, if either the ITS 1 or ITS 2 region displayed three or four bands, the ITS was interpreted as heterozygous (44). het, heterozygous; hm, homozygous.