Animals of Taita Hills Wildlife Sanctuary

Peer reviewe

Symbiotic cyanobacteria in lichens

Cyanolichens are obligate symbioses between fungi and cyanobacteria. They occur in many types of environments ranging from Arctic tundra and semi-deserts to tropical rainforests. Possibly even a majority of their global species diversity has not yet been described. Symbiotic cyanobacteria provide both photosynthate and fixed nitrogen to the fungal host and the relative importance of these functions differs in different cyanolichens. The cyanobiont can either be the sole photosynthetic partner or a secondary symbiont in addition to a primary green algal photobiont. In addition, the cyanolichen thallus may incorporate a plethora of other microorganisms. The fungal symbionts in cyanolichens are almost exclusively ascomycetes. Nostoc is by far the most commonly encountered cyanobacterial genus. While the cyanobacterial symbionts are presently not readily identifiable to species, molecular methods work well on the generic level and offer practical means for identifying symbiotic cyanobacterial genotypes. The present diversity of lichen cyanobionts may partly reflect the evolutionary effects of their lichen-symbiotic way of life and dispersal.Peer reviewe

Habitat shifts and morphological variation of Pseudevernia furfuracea along a topographic gradient

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The liverworts (Bryophyta) of the Julmat Lammet Nature Reserve, central Finland

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Ordination analysis of tRNALeu (UAA) intron sequences in lichen-forming Nostoc strains and other cyanobacteria

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Two new species of Caliciopsis (Coryneliaceae) from Hunan Province, China

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Chaenotheca olivaceorufa (Caliciales) new to North America

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Cyanobacteria in terrestrial symbiotic systems

Filamentous cyanobacteria are important primary producers and N2 fixers in many terrestrial environments. As reduced nitrogen is often limiting, some thalloid liverworts (Marchantiophyta), hornworts (Anthocerophyta), the water fern Azolla (Salviniales), cycads (Cycadophyta), and the angiosperm Gunnera (Gunnerales) have evolved the ability to establish stable and structurally well-defined symbioses with N2-fixing cyanobacteria. Also a wide diversity of lichen-forming fungi have cyanobacteria as photosynthetic symbionts or as N2-fixing symbionts. Cyanolichen symbioses have evolved independently in different fungal lineages, and evolution has often resulted in convergent morphologies in distantly related groups. DNA techniques have provided a wealth of new information on the diversity of symbiotic cyanobacteria and their hosts. The fact that many plants and fungi engage in many different symbioses simultaneously underlines the probable significance of diffuse evolutionary relationships between different symbiotic systems, including cyanobacterial and mycorrhizal associations. This review introduces the reader to recent research on symbiotic cyanobacteria in terrestrial ecosystems and shortly describes the astonishing range of diversity in these ecologically important associations.Peer reviewe