Tagged: Ferns




Cyanobacteria: Good week, or bad week..? Part III

This is the third of our quartet of posts looking at the newsworthy world of the blue-greens. Asteroids, bad for dinosaurs, but good for cyanobacteria? This really good news for cyanobacteria – both benign and bad blue-green species – comes from investigation into the consequences of the Chicxulub asteroid. This is the Yucatán Peninsula (in modern-day México)-denting phenomenon that is implicated in causing a mass extermination event, the K-T (Cretaceous-Tertiary) or, alternatively, the end-Cretaceous, or even the Cretaceous-Paleogene (K-Pg) Extinction, approx. 66 millions of years ago (Ma) (Peter Schulte et al., 2010). Attention-grabbingly, and a sensationalist headline-writer’s dream come true,...

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Plant economics spectrum theory holds true within ferns

Plants usually have limited resources in one way or another. There is only so much nutrient in the soil. How best to use it? The plant economics spectrum theory integrates the coordination of plant functional traits along a resource acquisition–conservation trade-off axis. The need for acquisition might vary with competition for resources. There’s plenty of evidence that supports the theory in seed plants, but Dunmei Lin and colleagues wondered if the same was true for ferns. If it was, then the same traits should also influence litter decomposition among coexisting ferns. Plants have varying traits in terms of morphology (shape)...

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Ecophysiology of early lineage vascular plants

Tropical understory communities are highly diverse, and plants in these environments must optimize functional traits to ensure ecological and evolutionary success. Campany et al. survey the ecophysiology of two spore bearing vascular plant groups, Selaginella and ferns, in a lowland Costa Rican tropical forest understory. Selaginella in shade has higher chlorophyll levels and lower light compensation points compared with open habitats, where foliar nitrogen was lower and stomatal densities higher. Co-occurring ferns optimized ecophysiological function differently in tropical forest floors, likely related to evolutionary constraints of micro- and megaphyll leaf physiology. These findings contribute to global explorations of vascular plant...

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Vandenboschia speciosa

Characterization of the satellitome in lower vascular plants: the case of the endangered fern Vandenboschia speciosa

Vandenboschia speciosa is a highly vulnerable fern species, with a large genome (10.5 Gb). Haploid gametophytes and diploid sporophytes are perennial, can reproduce vegetatively, and certain populations are composed only of independent gametophytes. These features make this fern a good model: for high-throughput analysis of satellite DNA (satDNA) to investigate possible evolutionary trends in satDNA sequence features; to determine the relative contribution of satDNA and other repetitive DNAs to its large genome; and to analyse whether the reproduction mode or phase alternation between long-lasting haploid and diploid stages influences satDNA abundance or divergence. Ruiz-Ruano et al. analysed the repetitive fraction...

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Habitat of the gametophytic fern Vittaria appalachiana

Conserved thermal performance curves across the geographic range of a gametophytic fern

Species-level responses to environmental change depend on the collective responses of their constituent populations and the degree to which these populations are specialized to local conditions. Thermal tolerance limits in ferns remain poorly understood, and even less is known about these limits at the population level. Being the second most diverse group of vascular land plants, this leaves a large gap in our understanding of how contemporary plant species will respond to elevated temperatures that will be occurring in the future. In a recent Editor’s Choice article published in AoBP, Chambers & Emery focus on thermal tolerance of the fern...

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Schematic representation of a stomatal complex.

Stomatal cell wall composition: distinct structural patterns in different phylogenetic groups

Stomata are pores regulating gas exchange in land plants. Stomatal morphology has remained largely consistent through ∼400 million years of plant evolution, though cell wall composition has changed. Shtein et al. investigate stomatal cell wall composition within a broad evolutionary spectrum of plants, including ferns, angiosperms and grasses. The data demonstrate distinct cell wall patterns in stomata of different phylogenetic groups, suggesting that crystalline cellulose (in angiosperms) may have replaced lignin (in ferns), serving a similar stomatal-wall strengthening function. Such taxon-specific spatial patterns of cell wall deposition might be a consequence of differences in environmental selection along the course of...

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Simplified models of the pattern of morphological disparity through the Phanerozoic.

Why should we investigate the morphological disparity of plant clades?

Macroevolution of major clades is often studied by plotting their taxonomic diversity through time. It is equally informative, but less commonplace, to investigate how clades explore anatomical ‘design’ space by quantifying their morphological disparity through time. Counterintuitively, diversity and disparity are usually decoupled. Metazoan clades often reach their highest disparity relatively early in their evolution, while diversity is still low. Oyston et al. show that this macroevolutionary rule of thumb holds true in a sample of major plant clades, and discuss the types of data and methodological approaches that will facilitate future work on plant disparity.

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Three types of spores detected in the experimental plant E_KUR.

Sporogenesis and offspring ploidy levels in hybrid Dryopteris ferns

In ferns, apomixis is an important mode of asexual reproduction. Although the mechanisms of fern reproduction have been studied thoroughly, most previous work has focused on cases in which ferns reproduce either exclusively sexually or exclusively asexually. Reproduction of ferns with potentially mixed systems and inheritance of apomixis remains largely unknown. Ekrt and Koutecký use flow cytometry to assess genome sizes in offspring of pentaploid Dryopteris × critica, a hybrid of triploid apomictic D. borreri and tetraploid sexual D. filix-mas. The hybrid under study is partly fertile and shows unstable sporogenesis. Formation of aborted spores, well-developed reduced spores and unreduced...

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