A plastid phylogeny of the fern genus Arachniodes (Dryopteridaceae).

Arachniodes (Dryopteridaceae) is one of the most confusing and controversial fern genera in terms of its circumscription, nomenclature, and taxonomy. Estimates of species number range from 40 to 200. Previous molecular works included only 2-17 accessions representing 2-12 species of Arachniodes and allied genera, leaving most of the Asian species remain unsampled and the infragneric relationships unclear. In this study DNA sequences of seven plastid markers of 343 accessions representing ca. 68 species of Arachniodes (275 accessions), and 64 outgroup accessions from subfam. Dryopteridoideae and subfam. Polybotryoideae were used to infer a phylogeny with maximum likelihood, Bayesian inference, and maximum parsimony approaches. Our major results include: (1) Two species currently assigned in Arachniodes (A. macrostegia and A. ochropteroides are resolved outside of the core Arachniodes making the currently defined Arachniodes polyphyletic, confirming earlier findings; (2) Lithostegia, Leptorumohra, and Phanerophlebiopsis are indeed synonyms of Arachniodes; (3) Leptorumohra is confirmed to be monophyletic, but Phanerophlebiopsis is polyphyletic; (4) The New World species of Arachniodes are confirmed to be not monophyletic with A. denticulata being nested within the Old World species, suggesting that this species is dispersed from the Old World; (5) Arachniodes s.s is resolved into 12 major clades, some of which are further divisable into recognizable subclades and groups, with A. mutica from Japan being resolved as the sister to the rest of the genus; (6) A number of systematic implications of the phylogeny have been suggested; and (7) the genus is estimated to contain ca. 83 species.

Global phylogeny and biogeography of the fern genus Ctenitis (Dryopteridaceae), with a focus on the Indian Ocean region.

The diverse and pantropical genus Ctenitis, in the Dryopteridaceae, has been largely ignored in phylogenetic studies until now. In this study, we fill in this gap by reconstructing the first comprehensive phylogeny of the genus including 53 species currently recognized in the genus Ctenitis, among which seven species formerly were assigned to the genus Pseudotectaria and one to Heterogonium. Special emphasis was given to the sampling of species occurring in the African-Indian Ocean region. The presented results include reconstruction of a biogeographic scenario based on estimated divergence times and ancestral area reconstruction. Our findings confirm the inclusion, within Ctenitis, of the Indian Ocean species formerly placed in Pseudotectaria and Heterogonium. The crown group divergence was estimated to date back to the Oligocene or Early Miocene. The biogeographical scenario indicates an initial divergence of the Asian-Pacific ranges and the neotropical ranges, and a subsequent colonization of the Afro-Madagascan region by a lineage with neotropical ancestors. The Afro-Madagascan lineage splits into a lineage endemic to the Mascarene islands and a lineage occurring in Madagascar, the Comoros and Africa. The range expansion towards Africa and Madagascar was estimated to date back to the late Miocene, whereas the estimated ages for the onset of the diversification of the Mascarene diversity is consistent with the ages of these young, volcanic islands. The absence of any extant species of Ctenitis with a multi-continental distribution range and the rarity of inter-island dispersal and speciation in the Indian Ocean region suggest a limited contribution of long distance dispersal to the biogeographical history of this fern genus, versus a high contribution of local speciation.

Using a multilocus phylogeny to test morphology-based classifications of Polystichum (Dryopteridaceae), one of the largest fern genera.

BACKGROUND: Polystichum (Dryopteridaceae) is probably the third largest fern genus in the world and contains ca. 500 species. Species of Polystichum occur on all continents except Antarctica, but its highest diversity is found in East Asia, especially Southwest China and adjacent regions. Previous studies typically had sparse taxon sampling and used limited DNA sequence data. Consequently, the majority of morphological hypotheses/classifications have never been tested using molecular data. RESULTS: In this study, DNA sequences of five plastid loci of 177 accessions representing ca. 140 species of Polystichum and 13 species of the closely related genera were used to infer a phylogeny using maximum likelihood, Bayesian inference, and maximum parsimony. Our analyses show that (1) Polystichum is monophyletic, this being supported by not only molecular data but also morphological features and distribution information; (2) Polystichum is resolved into two strongly supported monophyletic clades, corresponding to the two subgenera, P. subg. Polystichum and P. subg. Haplopolystichum; (3) Accessions of P. subg. Polystichum are resolved into three major clades: clade K (P. sect. Xiphophyllum), clade L (P. sect. Polystichum), and the HYMASO superclade dominated by accessions of P. sect. Hypopeltis, P. sect. Macropolystichum, and P. sect. Sorolepidium, while those of P. subg. Haplopolystichum are resolved into eight major clades; and (4) The monophyly of the Afra clade (weakly supported), the Australasian clade (weakly supported), and the North American clade (strongly supported) is confirmed. CONCLUSIONS: Of the 23 sections of Polystichum recognized in a recent classification of the genus, four (P. sect. Hypopeltis, P. sect. Neopolystichum, P. sect. Sorolepidium, P. sect. Sphaenopolystichum) are resolved as non-monophyletic, 16 are recovered as monophyletic, and three are monospecific. Of the 16 monophyletic sections, two (P. sect. Adenolepia, P. sect. Cyrtogonellum) are weakly supported and 14 are strongly supported as monophyletic. The relationships of 11 sections (five in P. subg. Haplopolystichum; six in P. subg. Polystichum) are well resolved.

A well-sampled phylogenetic analysis of the polystichoid ferns (Dryopteridaceae) suggests a complex biogeographical history involving both boreotropical migrations and recent transoceanic dispersals.

Intercontinental disjunctions in ferns have often been considered as the result of long-distance dispersal (LDD) events rather than of vicariance. However, in many leptosporangiate groups, both processes appear to have played a major role in shaping current geographical distribution. In this study, we reconstructed the phylogenetic relationships and inferred the ancestral distribution areas of the polystichoid ferns (Cyrtomium, Phanerophlebia, and Polystichum), to evaluate the relative impact of vicariance and LDD on the biogeography of this group. We used a molecular dataset including 3346 characters from five plastid loci. With 190 accessions our taxon coverage was about three times as large as any previous worldwide sampling. Biogeographical analyses were performed using S-DIVA and S-DEC and divergence times were estimated by integrating fossil and secondary calibrations. The polystichoid ferns are a monophyletic clade that may have originated in East Asia during the Eocene, an age much younger than previously estimated. Three transoceanic disjunctions between East Asia and New World were identified in the Paleogene: one for Phanerophlebia during late Eocene (34Ma, 19-51Ma), and two in Polystichum at the Eocene-Oligocene boundary (30Ma, 18-43Ma; 28Ma, 19-39Ma respectively). During the Neogene, further range expansions took place from Asia to Africa, Hawaii, and the Southwestern Indian Ocean region. Our results indicate that early transfers between the Old and the New World are compatible with a boreotropical migration scenario. After evolving in Asia during the Eocene, the polystichoid ferns reached the New World in independent migrations at the Eocene-Oligocene boundary through the boreotropical belt. However, although less likely, the alternative hypothesis of independent transoceanic dispersals from the Old to the New World cannot be ruled out. Further range expansion during the Neogene was most likely the result of long-distance dispersal (LDD).

Paraphyly of Cyrtomium (Dryopteridaceae): evidence from rbcL and trnL-F sequence data.

Cyrtomium is an Asiatic genus characterized by anastomosing veins with included veinlets, and comprises about 40 species. We sequenced rbcL and trnL-F sequences of 19 species of Cyrtomium and eight species from related genera in order to elucidate a molecular phylogeny of the genus using maximum-parsimony methods. The phylogenetic trees did not agree with traditional classifications. Cyrtomium was resolved as paraphyletic, and a clade including subseries Balansana of Cyrtomium, Cyrtogonellum, Polystichum subacutidens and Cyrtomidictyum (the BCPC clade) and a second one containing Cyrtomium sensu stricto were monophyletic. The results also implied that: (1) C. uniseriale was synonymous with C. balansae; (2) C. falcatum was likely the female parent of C. devexiscapulae; and (3) based on the rbcL and trnL-F sequence data, C. nephrolepioides and C. grossum were the female parents of C. shingianum and C. chingianum, respectively, although other evidence is needed for the confirmation of this hypothesis.

[Herbalogical textual study on "guanzhong"].

Herbalogical textual study indicated "Guanzhong" recorded in Bencaojing at Han Dynasty had pteridophyte characters. In the period of Wei and Jin Dynasties, the name of "Guanzhong" was really belonged to spermatophyte. Since Southern and Northern Dynasties, fern has been the main source of "Guanzhong" in which Woowardia japonica was used longer than others.

Seasonal changes in polar lipids in fronds of the ferns Dryopteris filix-mas and Matteuccia struthiopteris.

The distribution pattern of total lipids, glyco- and phospholipids, and one betaine lipid (DGTS) in the fronds ofthe ferns Dryopteris filix-mas and Matteuccia struthiopteris was studied. The lipid composition of the embryo leaflets forming a bud, or "treble clef", and that of fully opened leaves changed throughout the growth season. The maximum amount of DGTS in clefs and mature leaves was detected at the beginning of the season. By midsummer, the DGTS content decreased, dropping to zero in the fully opened leaves, and then increased again. The amount of DGTS in the clefs collected in October versus those collected in May was somewhat higher in the case of Dryopteris filix-mas and almost twofold lower in the case of Matteuccia struthiopteris. The ratio between polar lipids contained in the clefs and mature leaves throughout the growth season was determined.