Four new species of the Genera Eudesme and Sphaerotrichia (Chordariaceae, Heterokontophyta) from the Chinese Coast

Four new species, Eudesme huanghaiensis Ding et Lu, E. qingdaoensis Ding et Lu, E. shandongensis Ding et Lu and Sphaerotrichia huanghaiensis Ding et Lu, from the western Yellow Sea coast of China are described. Eudesme huanghaiensis is mainly characterized by its spherical or sub-spherical sub-cortical cells, its rhizoidal filaments developing from the basal cells of sub-cortex and its broad sub-cortical and medullary layers. E. qingdaoensis is mainly characterized by its long medullary cells, generally hollow center of the medulla, short sub-cortex with only 3-4 cylindrical cells and long, slender and clavate terminal cells of the rhizoidal filaments. E. shandongensis is mainly characterized by its hollow frond, thick cell walls of both medulla and inner sub-cortical layers and the spherical terminal cells of the rhizoid filaments. Sphaerotrichia huanghaiensis is mainly characterized by its cylindrical, sparsely branched frond with acute angle, and its thick 5-6 layered sub-cortex with long assimilating filaments of 6-10 cells.

Phylogenetic analyses of some genera in Oedipodidae (Orthoptera : Acridoidea) based on 16S mitochondrial partial gene sequences

Based on the 16S mitochondrial partial gene sequences of 29 genera, containing 26 from Oedipodidae and one each from Tanaoceridae, Pyrgomorphidae and Tetrigidae (as outgroups), the homologus sequences were compared and phylogenetic analyses were performed. A phylogenetic tree was inferred by neighbor-joining (NJ). The results of sequences compared show that: (i) in a total of 574 bp of Oedipodidae, the number of substituted nucleotides was 265 bp and the average percentages of T, C, A and G were 38.3%, 11.4%, 31.8% and 18.5%, respectively, and the content of A+T (70.1%) was distinctly richer than that of C+G (29.9%); and (ii) the average nucleotide divergence of 16S rDNA sequences among genera of Oedipodidae were 9.0%, among families of Acridoidea were 17.0%, and between superfamilies (Tetrigoidea and Acridoidea) were 23.9%, respectively. The phylogenetic tree indicated: (i) the Oedipodidae was a monophyletic group, which suggested that the taxonomic status of this family was confirmed; (ii) the genus Heteropternis separated from the other Oedipodids first and had another unique sound-producing structure in morphology, which is the type-genus of subfamily Heteropterninae; and (iii) the relative intergeneric relationship within the same continent was closer than that of different continents, and between the Eurasian genera and the African genera, was closer than that between Eurasians and Americans.

Molecular phylogeny of some genera of Pamphagidae (Acridoidea, Orthoptera) from China based on mitochondrial 16S rDNA sequences

Based on the mitochondrial 16S ribosomal DNA partial sequences (473 bp) of 9 species of Pamphagidae (Acridoidea, Orthoptera) from China and of 4 species of Pamphagidae and 2 species of Pyrgomorphidae and Acrididae (as outgroups) retrieved from GenBank, we constructed the molecular phylogeny using the Neighbor Joining (NJ) and Minimum Evolution ( ME) methods based on the nucleotide Kimura 2-parameter model. The results of our study shown that: 1) the ranges of the 16S rDNA nucleotide divergence between two species of a genus were 0.21%, among genera of a subfamily were 0.42-3.38%, and among subfamilies of Pamphagidae were 1.90-8.88%, respectively. The phylogenetic tree shows that: 1) all Pamphagidae taxa form a monophyletic clade, and are well separated from the outgroup; 2) the African taxa Porthetinae (Lobosceliana brevicornis) and Akicerinae (Batrachotetrix sp.) are distinctly separated from the Chinese taxa Prionotropisinae; 3) Haplotropis bruneriana and Glauia terrea of Pamphaginae are nested in the middle of the tree, but their phylogenetic status is uncertain in this study; 4) 8 genera of Asiotmethis, Beybienkia, Mongolotmethis, Sinotmethis, Rhinotmethis, Filchnerella, Eotmethis and Pseudotmethis from China are all grouped into the subfamily Prionotropisinae, but their phylogenetic relationships are not clearly resolved.

The rapid assignment of ruminal fungi to presumptive genera using ITS1 and ITS2 RNA secondary structures to produce group-specific fingerprints

Danny S. Tuckwell, Matthew J. Nicholson, Christopher S. McSweeney, Michael K. Theodorou and Jayne L. Brookman (2005). The rapid assignment of ruminal fungi to presumptive genera using ITS1 and ITS2 RNA secondary structures to produce group-specific fingerprints. Microbiology, 151 (5) pp.1557-1567 Sponsorship: BBSRC / Stapledon Memorial Trust RAE2008

Natural hybridization between genera that diverged from each other approximately 60 million years ago.

A fern from the French Pyrenees-×Cystocarpium roskamianum-is a recently formed intergeneric hybrid between parental lineages that diverged from each other approximately 60 million years ago (mya; 95% highest posterior density: 40.2-76.2 mya). This is an extraordinarily deep hybridization event, roughly akin to an elephant hybridizing with a manatee or a human with a lemur. In the context of other reported deep hybrids, this finding suggests that populations of ferns, and other plants with abiotically mediated fertilization, may evolve reproductive incompatibilities more slowly, perhaps because they lack many of the premating isolation mechanisms that characterize most other groups of organisms. This conclusion implies that major features of Earth's biodiversity-such as the relatively small number of species of ferns compared to those of angiosperms-may be, in part, an indirect by-product of this slower "speciation clock" rather than a direct consequence of adaptive innovations by the more diverse lineages.

Linnaeus was right all along: Ulva and Enteromorpha are not distinct genera.

Ulva, one of the first Linnaean genera, was later circumscribed to consist of green seaweeds with distromatic blades, and Enteromorpha Link was established for tubular forms. Although several lines of evidence suggest that these generic constructs are artificial, Ulva and Enteromorpha have been maintained as separate genera. Our aims were to determine phylogenetic relationships among taxa currently attributed to Ulva, Enteromorpha, Umbraulva Bae et I.K. Lee and the monotypic genus Chloropelta C.E. Tanner, and to make any nomenclatural changes justified by our findings. Analyses of nuclear ribosomal internal transcribed spacer DNA (ITS nrDNA) (29 ingroup taxa including the type species of Ulva and Enteromorpha), the chloroplast-encoded rbcL gene (for a subset of taxa) and a combined data set were carried out. All trees had a strongly supported clade consisting of all Ulva, Enteromorpha and Chloropelta species, but Ulva and Enteromorpha were not monophyletic. The recent removal of Umbraulva olivascens (P.J.L. Dangeard) Bae et I.K. Lee from Ulva is supported, although the relationship of the segregate genus Umbraulva to Ulvaria requires further investigation. These results, combined with earlier molecular and culture data, provide strong evidence that Ulva, Enteromorpha and Chloropelta are not distinct evolutionary entities and should not be recognized as separate genera. A comparison of traits for surveyed species revealed few synapomorphies. Because Ulva is the oldest name, Enteromorpha and Chloropelta are here reduced to synonymy with Ulva, and new combinations are made where necessary.