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- Mellado-Mansilla, D., et al.
(författare)
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The relationship between chlorophyllous spores and mycorrhizal associations in ferns: evidence from an evolutionary approach
- 2022
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 109:12, s. 2068-2081
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Tidskriftsartikel (refereegranskat)abstract
- PremiseApproximately 14% of all fern species have physiologically active chlorophyllous spores that are much more short-lived than the more common and dormant achlorophyllous spores. Most chlorophyllous-spored species (70%) are epiphytes and account for almost 37% of all epiphytic ferns. Chlorophyllous-spored ferns are also overrepresented among fern species in habitats with waterlogged soils, of which nearly 60% have chlorophyllous spores. Ferns in these disparate habitat types also have a low incidence of mycorrhizal associations. We therefore hypothesized that autotrophic chlorophyllous spores represent an adaptation of ferns to habitats with scarce mycorrhizal associations. MethodsWe evaluated the coevolution of chlorophyllous spores and mycorrhizal associations in ferns and their relation to habitat type using phylogenetic comparative methods. ResultsAlthough we did not find support for the coevolution of spore type and mycorrhizal associations, we did find that chlorophyllous spores and the absence of mycorrhizal associations have coevolved with epiphytic and waterlogged habitats. Transition rates to epiphytic and waterlogged habitats were significantly higher in species with chlorophyllous spores compared to achlorophyllous lineages. ConclusionsSpore type and mycorrhizal associations appear to play important roles in the radiation of ferns into different habitat types. Future work should focus on clarifying the functional significance of these associations.
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| 2. |
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| 3. |
- Schuettpelz, Eric, et al.
(författare)
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A community-derived classification for extant lycophytes and ferns
- 2016
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Ingår i: Journal of Systematics and Evolution. - : Wiley. - 1674-4918 .- 1759-6831. ; 54:6, s. 563-603
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Tidskriftsartikel (refereegranskat)abstract
- Phylogeny has long informed pteridophyte classification. As our ability to infer evolutionary trees has improved, classifications aimed at recognizing natural groups have become increasingly predictive and stable. Here, we provide a modern, comprehensive classification for lycophytes and ferns, down to the genus level, utilizing a community-based approach. We use monophyly as the primary criterion for the recognition of taxa, but also aim to preserve existing taxa and circumscriptions that are both widely accepted and consistent with our understanding of pteridophyte phylogeny. In total, this classification treats an estimated 11 916 species in 337 genera, 51 families, 14 orders, and two classes. This classification is not intended as the final word on lycophyte and fern taxonomy, but rather a summary statement of current hypotheses, derived from the best available data and shaped by those most familiar with the plants in question. We hope that it will serve as a resource for those wanting references to the recent literature on pteridophyte phylogeny and classification, a framework for guiding future investigations, and a stimulus to further discourse.
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| 4. |
- Mehltreter, K., et al.
(författare)
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Hydathodes in ferns: their phylogenetic distribution, structure and function
- 2022
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Ingår i: Annals of Botany. - : Oxford University Press (OUP). - 0305-7364 .- 1095-8290. ; 130:3, s. 331-344
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims Ferns are the second largest group of vascular plants and are distributed nearly worldwide. Although ferns have been integrated into some comparative ecological studies focusing on hydathodes, there is a considerable gap in our understanding of the functional anatomy of these secretory tissues that are found on the vein endings of many fern leaves. In this study, we aimed to investigate the phylogenetic distribution, structure and function of fern hydathodes. Methods We performed a global review on fern hydathodes and their phylogenetic distribution, carried out an ancestral character state reconstruction, and studied the structure, guttation and elemental composition of salt residues of eight species, and the diurnal patterns of xylem pressure of two species. Key Results Hydathodes are known from 1189 fern species, 92 genera and 19 families of 2 orders, Equisetales and Polypodiales. Stochastic character mapping indicated multiple gains and losses of hydathodes at the genus level, occurring especially during the last 50 million years of fern evolution. Hydathodes were located on the adaxial leaf surface and characterized by a cytoplasm-rich, pore-free epidermis, and became functional for several weeks after nearly complete leaf expansion. In two species, positive xylem pressure built up at night, potentially facilitating guttation. Guttation fluid was rich in Ca and often Si, but also contained P, Mg, Na and Al. Conclusions Stochastic character mapping and the structural and functional diversity of hydathodes indicate multiple origins, and their presence/absence in closely related taxa implies secondary losses during fern evolution. Positive xylem pressure and high air humidity play an important role as drivers of guttation. Hydathodes may contribute to the regulation of leaf nutrient stoichiometry by the release of excessive compounds and minerals other than waste products, but the presence of essential chemical elements in salt residues also indicates possible leakage.
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| 5. |
- Molino, S., et al.
(författare)
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First Record of Sporangiasters in the Blechnaceae
- 2021
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Ingår i: American Fern Journal. - : American Fern Society. - 0002-8444. ; 111:3, s. 196-204
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Tidskriftsartikel (refereegranskat)abstract
- Sporangiasters are an uncommon type of paraphyses, occurring in a handful of leptosporangiate fern genera. We report sporangiasters in Parablechnum nesophilum, which is their first recorded occurrence in the Blechnaceae. We provide evidence of their homology to sporangia and discuss their functional significance. The presence of sporangiasters in P. nesophilum is surprising because the species has a well-developed indusium, and paraphyses are generally most common in exindusiate ferns. We surmise that these sporangiasters act as a second stage of protection for the developing sporangia after the indusium retracts. Alternatively, it is possible that sporangiasters may influence the vagility of spores by inhibiting dehiscence and limiting the ability of the annulus to disperse its spores.
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| 6. |
- Rothfels, Carl J., et al.
(författare)
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A revised family-level classification for eupolypod II ferns (Polypodiidae: Polypodiales)
- 2012
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 61:3, s. 515-533
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Tidskriftsartikel (refereegranskat)abstract
- We present a family-level classification for the eupolypod II clade of leptosporangiate ferns, one of the two major lineages within the Eupolypods, and one of the few parts of the fern tree of life where family-level relationships were not well understood at the time of publication of the 2006 fern classification by Smith & al. Comprising over 2500 species, the composition and particularly the relationships among the major clades of this group have historically been contentious and defied phylogenetic resolution until very recently. Our classification reflects the most current available data, largely derived from published molecular phylogenetic studies. In comparison with the five-family (Aspleniaceae, Blechnaceae, Onocleaceae, Thelypteridaceae, Woodsiaceae) treatment of Smith & al., we recognize 10 families within the eupolypod II clade. Of these, Aspleniaceae, Thelypteridaceae, Blechnaceae, and Onocleaceae have the same composition as treated by Smith & al. Woodsiaceae, which Smith & al. acknowledged as possibly non-monophyletic in their treatment, is circumscribed here to include only Woodsia and its segregates; the other "woodsioid" taxa are divided among Athyriaceae, Cystopteridaceae, Diplaziopsidaceae, Rhachidosoraceae, and Hemidictyaceae. We provide circumscriptions for each family, which summarize their morphological, geographical, and ecological characters, as well as a dichotomous key to the eupolypod II families. Three of these families-Diplaziopsidaceae, Hemidictyaceae, and Rhachidosoraceae-were described in the past year based on molecular phylogenetic analyses; we provide here their first morphological treatment.
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| 7. |
- Suissa, J. S., et al.
(författare)
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Mountains, climate and niche heterogeneity explain global patterns of fern diversity
- 2021
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 48:6, s. 1296-1308
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Tidskriftsartikel (refereegranskat)abstract
- Aim It is well known that the distribution of species diversity is spatially heterogeneous, but understanding the factors contributing to this heterogeneity and to the formation of biodiversity hotspots remains a challenge. Here, we seek to improve our understanding of how historical, ecological and evolutionary processes contribute to current patterns of global fern diversity. Location Worldwide. Taxon Ferns. Methods To evaluate the drivers of global fern diversity, we integrate over 800,000 georeferenced species occurrence records of nearly 8000 species, a time-calibrated phylogeny and seven climate and environmental layers. We use these data to summarize diversity and evolutionary patterns at a resolution of 100 x 100 km, and identify hotspots of fern species richness and endemism. We compare these hotspots to neighbouring non-hotspot regions to provide insight into the factors controlling global patterns of fern diversity. Results Tropical and subtropical mountains harbour a disproportionate amount of species relative to the land area they occupy; 58% of global species richness occur in eight principally montane hotspots together comprising just 7% of Earth's land area. We identify hotspots of fern species richness and endemism that are universally characterized by disproportionately high ecological variation. We demonstrate that total fern species richness scales linearly with available climate space at regional and global scales. Main Conclusions Areas of high environmental heterogeneity harbour a disproportionate amount of fern species, and global patterns of extant fern diversity reflect the distribution of these areas, especially in mountains at lower latitudes. Persistence of ancient lineages in areas with long-term climatic stability helps explain exceptional endemism in regions such as Malesia.
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