Mycocaliciales-lahkoon kuuluvien pihkalla kasvavien sienilajien monimuotoisuus ja evoluutio

Species of Mycocaliciales are a group of small ascomycetes with pin-like ascocarps. Among Fungi, many mycocalicioid species are rather unique in having specialized to live on the resinous exudates of vascular plants. Terpenoid and phenolic resins essentially are repellents for fungi, but some of these species even appear to use resins for their nutrition. This peculiar ecology has a long evolutionary history, judging from 20 to 40 Ma old amber fossils, in which the ascocarps growing on ancient resin bear remarkable resemblance to those of extant resinicolous species. In addition to resinicolous species, mycocalicioid fungi also include species that are saprotrophic on lignum or associated with lichens or non-symbiotic algal colonies. The aim of this theses was to study the diversity, ecology and evolutionary relationships of mycocalicioid fungi, especially the resinicolous species. The study is based on specimens collected from different parts of the world, and analyzed using both molecular and morphological methods. In this study seven new resinicolous Chaenothecopsis species are described from boreal North America and Europe, tropical Africa, and temperate China, four from angiosperm exudates and three from conifer resins. Two newly found fossils of Chaenothecopsis from Eocene and Oligocene ambers are described and their relations to extant species are elucidated. The phylogenetic relationships of several species and lineages, and the evolution of the resinicolous ecology are discussed in considerable detail. In addition, new morphological and chemical characters that can be used in future taxonomic studies are described.Kotelosieniin kuuluvan Mycocaliciales-lahkon lajit ovat pieniä, mustia ja nuppineulamasia. Lahkon lajeista hämmästyttävän suuri osa on erikoistunut kasvamaan erilaisilla putkilokasvien pihkamaisilla eritteillä. Terpeeniset ja fenoliset pihkat ovat useimmille sienilajeille myrkyllisiä, mutta Mycocaliciales-lahkon lajeista monet näyttäsivät jopa käyttävän pihkaa ravintonaan. Tämä ainutlaatuinen ekologia näyttäisi olevan evolutiivisesti hyvin vanhaa alkuperää, sillä 20-40 miljoonaa vuotta vanhoissa meripihkapaloissa säilyneet fossiiliset lajit muistuttavat suuresti nykyisiä pihkalla kasvavia lajeja. Mycocaliciales-lahkoon kuuluu myös lahopuulla ja jäkälien tai viherlevien yhteydessä kasvavia lajeja. Tässä väitöskirjassa tutkittiin erityisesti pihkalla kasvavien Mycocaliciales-lahkon lajien monimuotoisuutta, ekologiaa ja evolutiivisiä sukulaisuussuhteita. Tutkimus perustuu näytteisiin, jotka on kerätty eri puolilta maailmaa. Näytteistä on tutkittu mikroskooppisia rakenteita ja niitä on analysoitu erilaisilla DNA:han perustuvilla menetelmillä. Tutkimuksen tuloksena kuvataan yhteensä seitsemän uutta pihkalla kasvavaa Chaenothecopsis-lajia Pohjois-Amerikan ja Euroopan havumetsävyöhykkeeltä, trooppisesta Afrikasta ja lehtimetsävyöhykkeeltä Kiinasta. Näistä lajeista neljä kasvaa koppisiemenisten puiden pihkalla ja kolme havupuiden pihkalla. Tutkimuksessa esitellään myös kaksi meripihkasta löytynyttä fossiilista Chaeonothecopsis-lajia, toinen Eoseeni- ja toinen Oligoseenikaudelta. Niiden sukulaisuussuhteita ja rakenteita verrataan nykyisin eläviin lajeihin. Useiden lajien ja kehityslinjojen fylogeneettisiä sukulaisuussuhteita sekä pihkalla kasvamisen ekologian evoluutiota tarkastellaan monipuolisesti. Lisäksi tutkimuksessa esitellään useita uusia kemiallisia ja rakenteellisia tuntomerkkejä, joita voidaan käyttää lahkon lajien tunnistamisessa ja tieteellisessä kuvaamisessa

Three resinicolous North American species of Mycocaliciales in Europe with a re-evaluation of Chaenothecopsis oregana Rikkinen

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Nomenclatural corrections in calicioid fungi

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Fungi of the Bitterfeld amber forest

Volume: 249 Host publication title: III. Bitterfelder Bernsteinkolloquium Host publication sub-title: Bitterfelder Bernstein und andere fossile Harze aus Mitteldeutschland. Proceeding volume: 249 Isbn(print): 978-3-86944-094-1Peer reviewe

Stuck in time – a new Chaenothecopsis species with proliferating ascomata from Cunninghamia resin and its fossil ancestors in European amber

Resin protects wounded trees from microbial infection, but also provides a suitable substrate for the growth of highly specialized fungi. Chaenothecopsis proliferatus is described growing on resin of Cunninghamia lanceolata from Hunan Province, China. The new fungus is compared with extant species and two new fossil specimens from Eocene Baltic and Oligocene Bitterfeld ambers. The Oligocene fossil had produced proliferating ascomata identical to those of the newly described species and to other extant species of the same lineage. This morphology may represent an adaptation to growing near active resin flows: the proliferating ascomata can effectively rejuvenate if partially overrun by fresh, sticky exudate. Inward growth of fungal hyphae into resin has only been documented from Cenozoic amber fossils suggesting comparatively late occupation of resin as substrate by fungi. Still, resinicolous Chaenothecopsis species were already well adapted to their special ecological niche by the Eocene, and the morphology of these fungi has since remained remarkably constant

Chaenothecopsis schefflerae (Ascomycota: Mycocaliciales): a widespread fungus on semi-hardened exudates of endemic New Zealand Araliaceae

Ascomycetes specialised to live on hardened plant exudates occur worldwide, but the number of species so far described is relatively small (c.30). Particularly within the genus Chaenothecopsis (Ascomycota:Mycocaliciales), many species produce their ascomata on hardened but still relatively fresh outpourings of conifer resin or angiosperm exudate. Temperate rainforests of New Zealand provide habitat for several endemic Chaenothecopsis species, including Chaenothecopsis schefflerae, which was previously known from a single sample collected from the exudate of Schefflera digitata (Araliaceae) in the early 1980s. Here we show that C.schefflerae is neither lost nor very rare, but occurs sporadically throughout New Zealand. The fungus does not primarily grow on Schefflera but on exudate of several species of Pseudopanax (Araliaceae),also endemic to the region. We compare the morphology of the new specimens to the type specimen of C. schefflerae and provide a detailed description of the new material. Phylogenetic analyses based on nuclear ITS and LSU rDNA place C.schefflerae together with other morphologically similar Chaenothecopsis species growing on angiosperm exudates.Peer reviewe

Effects of local forest continuity on the diversity of fungi on standing dead pines

Human-induced fragmentation affects forest continuity, i.e. availability of a suitable habitat for the target species over a time period. The dependence of wood-inhabiting fungi on landscape level continuity has been well demonstrated, but the importance of local continuity has remained controversial. In this study, we explored the effects of local forest continuity (microhabitat and stand level) on the diversity of wood-inhabiting fungi on standing dead trunks of Scots pine (Paws sylvestris L.). We studied species richness and community composition of decomposers and Micarea lichens on 70 trunks in 14 forests in central Finland that differed in their state of continuity. We used dendrochronological methods to assess the detailed history of each study trunk, i.e. the microhabitat continuity. The stand continuity was estimated as dead wood diversity and past management intensity (number of stumps). We recorded 107 species (91 decomposers, 16 Micarea lichens), with a total of 510 occurrences. Using generalized linear mixed models, we found that none of the variables explained decomposer species richness, but that Micarea species richness was positively dependent on the time since tree death. Dead wood diversity was the most important variable determining the composition of decomposer communities. For Micarea lichens, the community composition was best explained by the combined effect of years from death, site and dead wood diversity. However, these effects were rather tentative. The results are in line with those of previous studies suggesting the restricted significance of local forest continuity for wood-inhabiting fungi. However, standing dead pines that have been available continuously over long periods seem to be important for species-rich communities of Micarea lichens. Rare specialists (e.g. on veteran trees) may be more sensitive to local continuity, and should be at the center of future research.Peer reviewe

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

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 Chaenothecopsis schefflerae, found on several endemic angiosperms in the family Araliaceae. Here we describe three new species; Chaenothecopsis matai 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 Prumnopitys taxifolia. 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.Peer reviewe

Estimating the Phanerozoic history of the Ascomycota lineages : Combining fossil and molecular data

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