PARENT SESSION
Oral Session #102: Soil Ecology: Mycorrhizae .
Presiding: N. Johnson
Friday, August 9. 9:00 AM to 12:00 PM. Apache Meeting Room, TCC.

Common mycorrhizal networks and host specificity patterns in a mixed evergreen California forest.

KENNEDY, PETER^*,1, IZZO, ANTONIO², BRUNS, THOMAS², ¹ Department of Integrative Biology, University of California, Berkeley, Berkeley, CA² Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA

ABSTRACT- To investigate patterns of mycorrhizal host specificity in a mixed evergreen California forest, we sampled the mycorrhizal community in three adjacent Douglas fir-tanoak stands on Mt. Tamalpais, Marin County, CA. Eighteen 10 x 30 cm cores (six per stand) were collected and mycorrhizal root tips were identified using molecular techniques (PCR, RFLP, and DNA sequencing of the rDNA ITS region). We found 168 unique RFLP types, 88 specific to Douglas fir, 58 specific to tanoak, and 22 associated with both hosts. Only 39 of the RFLP types were encountered in multiple cores; 14 specific to Douglas fir, three specific to tanoak, and 22 associated with both hosts. Of the RFLP types for which host specificity could be determined (those encountered more than once), multi-host fungi had the highest frequency and abundance. For the 22 RFLP types associated with both hosts, 13 were present on both hosts within at least one core. This suggests Douglas fir and tanoak may be connected by common mycorrhizal networks in the field. Additionally, our results indicate that multi-host species may be more abundant than host-specific species in a mixed evergreen California forest.

KEY WORDS: ectomycorrhizae, host specificity, common mycorrhizal network, mixed evergreen forest