Benito C. Tan

Bryophyte Biology: Bryogeography and conservation of bryophytes

Introduction Except for the marine environment, bryophytes, as a group, are nearly cosmopolitan in distribution. Because of the small size of spores and the frequent occurrence of vegetative propagules, bryophytes are easily dispersed across the landscape. Consequently, many show much wider distribution patterns than the seed plants (Watson 1974). This is especially true at the family and generic levels. The purported greater age of bryophytes may have contributed further to the wider range of bryophytes (Schofield 1992). The ecological and biological factors shaping the distribution patterns of seed plants have also affected the bryophytes. Indeed, like the seed plants, many bryophyte species found in the arctic and boreal zones are the same in North America, Asia, and Europe. In the tropics, there is a significant number of moss taxa that are pantropical, but the number is far lower when compared to the circumboreal taxa. Although a great number of bryophyte genera and species are cosmopolitan and distributed throughout different climatic regions, many do exhibit a disrupted or narrow range. The latter represent the uncommon, rare and endemic bryophytes. Their ultimate survival is critically dependent on the preservation of their natural habitats. Factors affecting the dispersal of bryophyte diaspores Diaspores are defined as any propagative parts of bryophytes, be they spores or gemmae, capable of giving rise to a new individual. Among the bryophytes, few members, like the moss family Splachnaceae, produce sticky spores that are dependent on flies for their dispersal.

Identifying a mysterious aquatic fern gametophyte

Süßwassertang, a popular aquatic plant that is sold worldwide in aquarium markets, has been long considered a liverwort because of its ribbon-like thallus. However, its antheridia are remarkably fern-like in morphology. To corroborate the hypothesis that Süßwassertang is a fern gametophyte and to determine its closest relative, we have sequenced five chloroplast regions (rbcL, accD, rps4–trnS, trnL intron, and trnL-F intergenic spacer), applying a DNA-based identification approach. The BLAST results on all regions revealed that Süßwassertang is a polypod fern (order: Polypodiales) with strong affinities to the Lomariopsidaceae. Our phylogenetic analyses further showed that Süßwassertang is nested within the hemi-epiphytic fern genus Lomariopsis (Lomariopsidaceae) and aligned very close to L. lineata. Our study brings new insights on the unexpected biology of Lomariopsis gametophytes—the capacity of retaining a prolonged gametophytic stage under water. It is of great interest to discover that a fern usually known to grow on trees also has gametophytes that thrive in water.

Nine New Records of Mosses from Doi Suthep-Pui National Park and a New Variety of Fissidens from Thailand

Abstract Nine species of mosses collected from Doi Suthep-Pui National Park are reported new to Thailand. Of these, Rhachithecium is a new generic record for the moss flora of Thailand. Notes on the ecology, morphology, taxonomy, and distribution of new records are included. Fissidens flaccidus Mitt. var. percurrens Wongkuna is described as a new variety from Thailand.

Entodon challengeri (Paris) cardot, the correct name for E. compressus sensu Mizushima and Crum and Anderson

ISSN 0040-0262. Entodon challengeri (Paris) Cardot is demonstrated to be the correct name for the taxon called E. compressus Mull. Hal. by Mizushima and by Crum and Anderson in their revisions and floristic account, respectively. Although validly published, Entodon compressus Mull. Hal. ex Cardot (1899) is shown to be an illegitimate later homonym of E. compressus (Hedw.) Mull. Hal. (1845), itself a synonym of Entodon cladorrhizans (Hedw.) Mull. Hal. (1845).

Tayloria rudimenta (Musci, Splachnaceae), a new species from Ningxia Huizu Autonomous Region of China

Tayloria rudimenta X.-L. Bai & B. C. Tan is described and illustrated as a new species based on a recent collection made from Helan Shan (Mt.), Ningxia Huizu Autonomous Region, China. The new species is characterized by the absence or with only rudimentary peristome, among the Chinese congeners.

Taxonomic Re-Assessment of Kindbergia (Brachytheciaceae, Bryophyta) in China, with a Description of Pseudokindbergia gen. nov.

Abstract — The distribution and systematic position of Kindbergia Ochyra in China is reevaluated. The phylogenetic analyses based on nuclear marker (ITS1-5.8S-ITS2) and chloroplastic markers (rpl16, trnG, and trnL-F) show that the alleged species of “Kindbergia” in China and Himalayas form a maximally supported clade (1.00 PP and 100 MPBS), which is closely related to the clade of Brachythecium Schimp., Eurhynchiadelphus Ignatov et Huttunen, and Myuroclada Besch., whereas the other Kindbergia specimens from Africa, America, Europe, Japan and the Southern Hemisphere form a monophyletic group, which is sister to Scleropodium Schimp. The specimens of Chinese species of “Kindbergia” are found, both molecularly and morphologically, to be identical with the Himalayan K. dumosa (Mitt.) Ignatov et Huttunen, and differ from Kindbergia specimens from other regions in the world in the shape of proximal branch leaves, operculum shape and capsule orientation. A new monotypic genus Pseudokindbergia M. Li, Y.F. Wang, Ignatov et B.C. Tan, is established to accommodate only the generitype P. dumosa (Mitt.) M. Li, Y.F. Wang, Ignatov et B.C. Tan, comb. nov. (≡ Hypnum dumosum Mitt.), and Bryhnia serricuspis (Mitt.) Y.F. Wang et R.L. Hu (≡ Eurhynchium serricuspis Mitt.) is considered synonymous with it.

Species Richness of Pteridophytes in Natural Versus Man-Made Lowland Forests in Malaysia and Singapore

The present research studies the effects on the diversity of pteridophytes after the conversion of natural forests to agricultural plantations. A study using the quadrat method was carried out to compare the similarities and differences in species richness and composition of pteridophytes in the natural and manmade forests in Johor State of Peninsular Malaysia and Singapore. Six non-contiguous quadrats measuring 10 m × 10 m were established in each of the five selected study sites consisting of natural forest, oil palm plantation and rubber plantation in both Johor and Singapore. Comparison was done using the Sorenson’s index of similarity, Detrended Correspondence Analysis (DCA), and the two-way indicator species analysis (TWINSPAN). The studies showed that the number of pteridophyte species captured by the 6 quadrats in the natural lowland forest seems comparable to that of the man-made forest. However, the species composition is different in the different types of forests. The pteridophytes maintain their diversity along a gradient from forest to agricultural landscapes by the replacement of shade-demanding and niche-specific species, to broad niche, opportunistic and sun-loving species.

Genetic diversity among clumps of Acanthorrhynchium papillatum (Harv.) M.Fleisch. as measured by variation in ITS2 sequences

Abstract Population genetic variation in the tropical moss species Acanthorrhynchium papillatum was evaluated using nucleotide sequences of the second Internal Transcribed Spacer (ITS2) region of the nuclear ribosomal DNA. High levels of variation were observed at both nucleotide and haplotype levels using this marker, indicating that the various populations in southern Peninsular Malaysia and Singapore have been genetically isolated to a large extent over time despite short spatial distances between some of the populations. Sequence analysis suggests that ITS2 diversity arises from high rates of mutation at this locus. In common with earlier results from microsatellite marker analysis, these results demonstrate that the genetic diversity of mosses may be high, as with higher plant species. Overall, relatively lower levels of diversity were seen in ITS2 loci compared to microsatellite markers. Thus the ITS2 region can be a useful additional DNA marker for analysing genetic diversity in this moss species.