Phylogeny, character evolution, and biogeography of the fern genus Bolbitis (Dryopteridaceae)

Bolbitis is a pantropical fern genus of Dryopteridaceae with ca. 80 species mainly in tropical Asia. Earlier studies confirmed the monophyly of Bolbitis when Mickelia is excluded and identified three major clades in Bolbitis. However, earlier studies are based on relatively small sampling and the majority of Asian species are not sampled. In this study, DNA sequences of three plastid markers of 169 accessions representing ca. 68 (85 % of total) species of Bolbitis in nine out of the 10 series recognized by Hennipman (1977), and 54 accessions representing the five remaining bolbitidoid genera are used to infer a global phylogeny with a focus on Asian species. The major results include: (1) Bolbitis is strongly supported as monophyletic; (2) species of Bolbitis are resolved into four major clades and their relationships are: the Malagasy/Mascarene clade is sister to the rest, followed by the African clade which is sister to the American clade + the Asian clade; (3) six well-supported subclades are identified in the most speciose Asian clade; (4) the free-veined Egenolfia is embedded in Bolbitis and is paraphyletic in relation to species with anastomosing venation; (5) three series sensu Hennipman (1977), B. ser. Alienae, B. ser. Egenolfianae, and B. ser. Heteroclitae, are paraphyletic or polyphyletic; (6) evolution of six morphological characters is analyzed and free venation is found to have evolved from anastomosing venation and reversed to free venation in Bolbitis; and (7) biogeographical implications are drawn and it is shown that a single recent dispersal from Asia resulted in continental disjunction of closely related ferns of Bolbitis between Africa and America.

Assessing effects of legacy nuclear waste on plants: Sensitive fern (Onoclea sensibilis) gametophyte viability at the Chalk River site

We evaluated the effects of chronic exposure to environmental radiological contamination on the reproductive fitness of sensitive fern (Onoclea sensibilis) by quantifying viability in haploid gametophytes of spores collected from ferns from background and contaminated areas of the Chalk River site. Dose rates measured in situ at field sites ranged from 60 to 849 μGy h^-1, with effects possible at the more contaminated sites (greater than 400 μGy h^-1). Fern spores were also irradiated from 1 to 1000 Gy to develop dose-response curves. We found no effects on gametophyte viability at the most contaminated areas of the Chalk River site, where we estimated growing season doses of 0.3-3.7 Gy. Dose-response curves show evidence of hormesis, with an increase in gametophyte viability up to 10 Gy, followed by a rapid decline to no viable gametophytes at doses of 1000 Gy. The sensitive fern is not a radiosensitive plant species, but effects do occur within the normal range (10-1000 Gy) of most plant species, making it useful as a sentinel species from a community perspective. Sensitive fern spore germination is high and stable over field dose ranges, with effects primarily on gametophyte viability. This method shows promise as an effects monitoring tool for sites with radiological contamination.

Antioxidant and hepatoprotective activity of ethanol extract of Arachniodes exilis (Hance) Ching

AIM OF THE STUDY

The study was aimed to investigate the ethanol extract of Arachniodes exilis for the antioxidant and hepatoprotective activity.

MATERIALS AND METHODS

Antioxidant activity was evaluated by different assays, including reducing power, lipid peroxidation, 2, 2'-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), superoxide anion, hydroxyl radicals and hydrogen peroxide. The hepatoprotective activity of ethanol extract was studied on mice liver damage induced by CCL(4) by monitoring biochemical parameters.

RESULTS

The extract showed potent activities on reducing power, lipid peroxide, DPPH, ABTS, superoxide anion, hydroxyl radical and hydrogen peroxide. And oral administration of Arachniodes exilis at different doses resulted in significant improvement on the levels of glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, malondialchehyche and superoxidedismutase.

CONCLUSION

The results indicate that this plant possesses potential antioxidant and hepatoprotective properties and has therapeutic potential for the treatment of liver diseases.

In vitro screening of traditionally used medicinal plants in China against Enteroviruses

AIM: To search for new antiviral agents from traditional Chinese medicine, specifically anti-enterovirosuses agents.

METHODS: The aqueous extracts (AE) of more than 100 traditionally used medicinal plants in China were evaluated for their In vitro anti-Coxsackie virus B3 activities with a MTT-based colorimetric assay.

RESULTS: The test for AE of 16 plants exhibited anti-Coxsackie virus B3 activities at different magnitudes of potency. They can inhibit three steps (inactivation, adsorption and replication) during the infection. Among the 16 plants, Sargentodoxa cuneata (Oliv.) Rehd. et Wils., Sophora tonkinensis Gapnep., Paeonia veitchii Lynch, Spatholobus suberectus Dunn. and Cyrtomium fortunei J. sm. also have activity against other enterovirus, including Coxsackie virus B5, Polio virus I, Echo virus 9 and Echo virus 29. Cell cytotoxic assay demonstrated that all tested AE had CC₅₀ values higher than their EC₅₀ values.

CONCLUSION: The sixteen traditionally used medicinal plants in China possessed antiviral activity, and some of them merit further investigations.