42 research outputs found

    Diversity and Functional Traits of Lichens in Ultramafic Areas: A Literature Based Worldwide Analysis Integrated by Field Data at the Regional Scale

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    While higher plant communities found on ultramafics are known to display peculiar characteristics, the distinguishability of any peculiarity in lichen communities is still a matter of contention. Other biotic or abiotic factors, rather than substrate chemistry, may contribute to differences in species composition reported for lichens on adjacent ultramafic and non-ultramafic areas. This work examines the lichen biota of ultramafics, at global and regional scales, with reference to species-specific functional traits. An updated world list of lichens on ultramafic substrates was analyzed to verify potential relationships between diversity and functional traits of lichens in different Köppen–Geiger climate zones. Moreover, a survey of diversity and functional traits in saxicolous communities on ultramafic and non-ultramafic substrates was conducted in Valle d’Aosta (North-West Italy) to verify whether a relationship can be detected between substrate and functional traits that cannot be explained by other environmental factors related to altitude. Analyses (unweighted pair group mean average clustering, canonical correspondence analysis, similarity-difference-replacement simplex approach) of global lichen diversity on ultramafic substrates (2314 reports of 881 taxa from 43 areas) displayed a zonal species distribution in different climate zones rather than an azonal distribution driven by the shared substrate. Accordingly, variations in the frequency of functional attributes reflected reported adaptations to the climate conditions of the different geographic areas. At the regional scale, higher similarity and lower species replacement were detected at each altitude, independent from the substrate, suggesting that altitude-related climate factors prevail over putative substrate–factors in driving community assemblages. In conclusion, data do not reveal peculiarities in lichen diversity or the frequency of functional traits in ultramafic areas

    Photobiont-mediated guilds in green algal lichens – an insight into the life of terrestrial symbiotic communities

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    Multiple alignment of the ITS rDNA locus sequences built using MAFFT v6, applying the Q-INS-i strategy, and improved by eliminating the ambiguously aligned regions using Gblocks v. 0.91b. Positions included in subsequent evolutionary analyses are indicated by mask

    Photobiont-mediated guilds in green algal lichens – an insight into the life of terrestrial symbiotic communities

    No full text
    Multiple alignment of the ITS rDNA locus sequences built using MAFFT v6, applying the Q-INS-i strategy, and improved by eliminating the ambiguously aligned regions using Gblocks v. 0.91b. Positions included in subsequent evolutionary analyses are indicated by mask

    Ecological differentiation of cryptic species in green microalgae

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    Abstract - 65th Meeting of the Phycological Society of Americ

    Lichens-a new source or yet unknown host of herbaceous plant viruses?

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    Abstract Lichens are symbiotic associations of fungi with green algae or cyanobacteria. They have arisen independently several times within the Ascomycota and Basidiomycota. This symbiosis became with time one of the most successful life forms on Earth. Outside of the symbiotic algae and fungi, there are endophytic fungi, other algae, and lichen-associated bacteria present within lichen thalli. Till now, no lichen-specific pathogens have been reported among bacteria and viruses. Around 15 dsRNA viruses are known from Eurotiomycetes and another dsRNA and reverse transcribed ssRNA viruses from Dothideomycetes containing some lichenized fungal lineages. Algal viruses have been identified from less than 1 % of known eukaryotic algal species but no virus has been found in Trebouxia or in Trentepohlia (Chlorophyta, Pleurastrophyceae, Pleurastrales), the most common green lichen photobionts. On the other hand, dsDNA viruses infecting related Chlorella algae are well known from freshwater phytoplankton. However, high-molecular weight dsRNA isolated from different lichen thalli indicated to us presence of ss or dsRNA viruses. A PCRbased search for viruses with genus-specific and speciesspecific primers resulted in amplification of genome segments highly identical with those of plant cytorhabdoviruses and with Apple mosaic virus (ApMV). The nucleotide sequence of the putative lichen cytorhabdovirus showed high identity (98 %) with Ivy latent cytorhabdovirus. The nucleotide sequences of six Apple mosaic virus isolates from lichens showed high similarity with ApMV isolates from apple and pear hosts. The lichen ApMV isolates were mechanically transmitted to an herbaceous host and detected positive in ELISA 14 days thereafter, which support its infectivity on plants. We prepared axenic cultures of photobionts identified as Trebouxia sp. from this ApMVpositive lichen samples. All these cultures were positive for ApMV in RT-PCR test. We suggest that lichens as a whole (or their photobionts, more specifically) could serve as reservoirs for viruses, despite the fact that the way of transmission between different organisms is not Eur J Plant Patho
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