GEOGRAPHIC SURVEY OF FUNGAL ENDOPHYTE COMMUNITY COMPOSITION IN LEAVESOF COASTAL REDWOOD

This geographic survey of the leaf fungal endophytes in Sequoia semper virens (coastal redwood) is the initial stage in a larger study to exp lore their symbiotic relationships. Leaves from six sites along a nort h to south transect, representing the range of Sequoia sempervirens fr om southern Oregon to the central coast of California, were sampled fo r endophytes within a 31-day period. Of the 16 species identified, one endophyte Pleuroplaconema sp. was isolated most frequently from all s ites, being detected in 55.4%-74.6% of leaves. The lowest percentage o f Pleuroplaconema sp. at the southernmost site also had the lowest tot al infection frequency with 18.6% of leaves being uninfected. Redwood at all other sites had between 1-4% frequency of uninfected leaves. Ot her species with consistent presence in the redwood populations were: Cryptosporiopsis abietina, Phomopsis occulta, Hypoxylon bipapillatum, Gelatinosporium sp., Nodulisporium sp., Geniculosporium sp, Aureobasid ium sp., and Phlyctema sp. The relatively constant endophyte compositi on in Sequoia sempervirens leaves along this nor-th to south transect provides a basis to explore the mutualistic, pathogenic and saprobic n ature of these endophytic relationships.