163 research outputs found
Biology and population studies of two endemic Nematoceras (orchid) species on sub-Antarctic Macquarie Island
Two endemic orchid species, Nematoceras dienemum and N. sulcatum, are known from sub-Antarctic Macquarie Island. Several additional orchid populations on the island are reported and deistogamy is documented in N. dienemum for the first time. The known population sizes, habitats and locations for both orchid species are documented here, and new information on their biology and population ecology is provided
Genetic diversity, mutagenesis and dispersal of Antarctic mosses - a review of progress with molecular studies
In investigating the extent of genetic diversity in Antarctic mosses the RAPD technique has proven especially useful in demonstrating that these mosses exhibit extensive genetic variation (levels being similar to those in temperate regions), and that within-colony variation is apparently caused not only by immigration and establishment of propagules from elsewhere, but also by mutagenesis. Dispersal of these mosses can also be followed using the RAPD technique; both short-distance dispersal by wind or water (depending on the moss species) and longer distance dispersal by wind across the ice cap has been demonstrated. Relationships with temperate mosses of the same species are being investigated to determine the origins of Antarctic populations. Genetic technology is also facilitating the taxonomic identification of moss specimens which cannot be identified morphologically due to phenotypic plasticity in Antarctica. Together, these genetic studies are starting to provide information of fundamental scientific importance for understanding the evolution, origins and dispersal mechanisms of Antarctic mosses, and their response to climate change.11 page(s
New records of three moss species (Ptychostomum pseudotriquetrum, Schistidium Antarctici, and Coscinodon lawianus) from the southern Prince Charles Mountains, Mac.Robertson Land, Antarctica
We have used a combination of traditional morphological examination and molecular DNA analysis to characterise 16 moss specimens collected from the Mawson Escarpment and Clemence Massif, exposures of bedrock and glacial debris in the southern Prince Charles Mountains of East Antarctica. The nuclear ribosomal ITS region and the chloroplast rps4 gene were sequenced and compared with those of other mosses known from coastal East Antarctica. The moss specimens from the southern Prince Charles Mountains were identified as Ptychostomum pseudotriquetrum (Hedw.) D. T. Holyoak and N. Pedersen, Schistidium antarctici (Cardot) 'L.I. Savicz & Smirnova' and Coscinodon lawianus (J.H. Willis) Ochyra. These constitute a new record for S. antarctici in the Prince Charles Mountains, and confirm and extend southwards previous records for P. pseudotriquetrum and C. lawianus in the region.7 page(s
- …