Chaenothecopsis (Mycocaliciales, Ascomycota) from exudates of endemic New Zealand Podocarpaceae

MycoKeys. 2023 Feb 16:95:101-129. doi: 10.3897/mycokeys.95.97601. eCollection 2023.

Abstract

The order Mycocaliciales (Ascomycota) comprises fungal species with diverse, often highly specialized substrate ecologies. Particularly within the genus Chaenothecopsis, many species exclusively occur on fresh and solidified resins or other exudates of vascular plants. In New Zealand, the only previously known species growing on plant exudate is Chaenothecopsisschefflerae, found on several endemic angiosperms in the family Araliaceae. Here we describe three new species; Chaenothecopsismatai Rikkinen, Beimforde, Tuovila & A.R. Schmidt, C.nodosa Beimforde, Tuovila, Rikkinen & A.R. Schmidt, and C.novae-zelandiae Rikkinen, Beimforde, Tuovila & A.R. Schmidt, all growing on exudates of endemic New Zealand conifers of the Podocarpaceae family, particularly on Prumnopitystaxifolia. Phylogenetic analyses based on ribosomal DNA regions (ITS and LSU) grouped them into a distinct, monophyletic clade. This, as well as the restricted host range, suggests that all three taxa are endemic to New Zealand. Copious insect frass between the ascomata contain ascospores or show an early stage of ascomata development, indicating that the fungi are spread by insects. The three new species represent the first evidence of Chaenothecopsis from any Podocarpaceae species and the first from any gymnosperm exudates in New Zealand.

Keywords: Chaenothecopsis; Mycocaliciales; New Zealand; Phyllocladus; Podocarpaceae; Prumnopitys; plant exudate; resinicolous fungi.