نتایج جستجو برای: ferns

تعداد نتایج: 2275  

2014
Shi-Bao Zhang Mei Sun Kun-Fang Cao Hong Hu Jiao-Lin Zhang

Ferns usually have relatively lower photosynthetic potential than angiosperms. However, it is unclear whether low photosynthetic potential of ferns is linked to leaf water supply. We hypothesized that there is an evolutionary association of leaf water transport capacity with photosynthesis and stomatal density in ferns. In the present study, a series of functional traits relating to leaf anatom...

2009
Kathryn L. Amatangelo Peter M. Vitousek

We evaluated differences in the rates and correlates of decomposition among 32 fern and angiosperm litter types collected in Hawai’i. Leptosporangiate ferns were separated into groups based on phylogeny: ‘polypod’ ferns, a monophyletic clade of ferns that diversified in the Cretaceous, and all other (‘non-polypod’) ferns that diversified earlier. We measured initial litter chemistry (nutrients ...

2014
Hyoung Tae Kim Myong Gi Chung Ki-Joong Kim

In this study, the chloroplast (cp) genome sequences from three early diverged leptosporangiate ferns were completed and analyzed in order to understand the evolution of the genome of the fern lineages. The complete cp genome sequence of Osmunda cinnamomea (Osmundales) was 142,812 base pairs (bp). The cp genome structure was similar to that of eusporangiate ferns. The gene/intron losses that fr...

2014
Emily B Sessa Jo Ann Banks Michael S Barker Joshua P Der Aaron M Duffy Sean W Graham Mitsuyasu Hasebe Jane Langdale Fay-Wei Li D Blaine Marchant Kathleen M Pryer Carl J Rothfels Stanley J Roux Mari L Salmi Erin M Sigel Douglas E Soltis Pamela S Soltis Dennis W Stevenson Paul G Wolf

Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. The...

Journal: :Tree physiology 1996
Jonathan Lyon William E. Sharpe

We assessed the impacts of hay-scented fern (Dennstaedtia punctilobula (Michx.) Moore) and subsoil liming (CaO amendments) on root and shoot growth of greenhouse-grown, first-year, northern red oak (Quercus rubra L.) seedlings. Red oak seedlings and ferns were grown in reconstructed soil profiles of four common Pennsylvanian forest soils. When grown in the presence of hay-scented ferns, with or...

Journal: :American journal of botany 2004
Kathleen M Pryer Eric Schuettpelz Paul G Wolf Harald Schneider Alan R Smith Raymond Cranfill

The phylogenetic structure of ferns (= monilophytes) is explored here, with a special focus on the early divergences among leptosporangiate lineages. Despite considerable progress in our understanding of fern relationships, a rigorous and comprehensive analysis of the early leptosporangiate divergences was lacking. Therefore, a data set was designed here to include critical taxa that were not i...

Journal: :Molecular phylogenetics and evolution 2005
Niklas Wikström Kathleen M Pryer

Using DNA sequence data from multiple genes (often from more than one genome compartment) to reconstruct phylogenetic relationships has become routine. Augmenting this approach with genomic structural characters (e.g., intron gain and loss, changes in gene order) as these data become available from comparative studies already has provided critical insight into some long-standing questions about...

2017
Madeline R Carins Murphy Gregory J Jordan Timothy J Brodribb

Producing leaves with closely spaced veins is a key innovation linked to high rates of photosynthesis in angiosperms. A close geometric link between veins and stomata in angiosperms ensures that investment in enhanced venous water transport provides the strongest net carbon return to the plant. This link is underpinned by "passive dilution" via expansion of surrounding cells. However, it is not...

Journal: :Molecular phylogenetics and evolution 2006
Petra Korall Kathleen M Pryer Jordan S Metzgar Harald Schneider David S Conant

Tree ferns are a well-established clade within leptosporangiate ferns. Most of the 600 species (in seven families and 13 genera) are arborescent, but considerable morphological variability exists, spanning the giant scaly tree ferns (Cyatheaceae), the low, erect plants (Plagiogyriaceae), and the diminutive endemics of the Guayana Highlands (Hymenophyllopsidaceae). In this study, we investigate ...

2011
Asim Mandal Amal Kumar Mondal

In this research, the occurrences of antimicrobial activity of some ferns were studied. The present paper dealt with the antimicrobial activities of some ethno-medicinally important ferns which were very common in West Mednapore District, as well as South West Bengal, against gram-positive and gramnegative bacterial pathogens. The plants were extracted with different solvents (70% ethanol, meth...

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