[Location: Location_Category='OCEAN', Location_Type='SOUTHERN OCEAN', Detailed_Location='Heard Island']
Population increase in Deschampsia Antarctica: genotypic variation or phenotypic plasticity?Entry ID: Deschampsia_project_NL_Wouw
Abstract: PROBLEM DEFINITION
Genetic exchange between local populations of Deschampsia Antarctica (Poaceae), one of the two phanerogams occurring in Antarctica, might be difficult. Dispersal of the species within and between vegetated areas is believed to be via rain splash and via birds, collecting tufts of the species for nesting material, thus facilitating both vegetative and generative dispersal, but ... this is probably of local importance only. Its long distance dispersion is unclear. And yet, the species has a large distribution area, ranging from the frigid Antarctic to oceanic and alpine habitats. A marked increase in numbers of individual plants in established populations, as well as a vigorous colonization of recently deglaciated areas over the last four decades has been reported. Recent publications report also vigorous flowering, as well as abundant seed set and presence of seedlings throughout its distribution area, often attributed to parameters of global change, especially temperature increase. The fact that the species becomes more reproductive with increasing temperature could be either a plastic response, or selection for more reproductive genotypes under a changing temperature regime, or both. The role of genetic variation and phenotypic plasticity in the adaptation of Deschampsia Antarctica to increasing temperatures and its recent colonization of deglaciated areas is the aim of this study.
-To investigate if colonization of new areas is restricted to special genotypes, which possess special traits or are more plastic than others.
-To establish the genotypic variation within and between geographically disjunct populations.
-To establish the level of plasticity in generative traits of Deschampsia Antarctica, with respect to the key environmental factors: temperature and moisture.
Using molecular techniques, the genotypic variation of D. Antarctica will be established in living samples and samples taken from herbarium specimens. From herbarium material only chlorophyll DNA can be successfully analyzed. Fresh material will be collected and preserved for the collection of nuclear DNA. Within and between population variability will be studied at the genotypic level using the overall AFLP fingerprint similarity as well as at the gene level, assuming Hardy Weinberg equilibriums (Schneider et al. 2000). Chloroplast DNA variation will be investigated using universal primers and digestion with restriction enzymes. This will provide phylogenetic analysis of the regions (phylogeography) and possibly allow a reconstruction of historical colonization patterns. The amount of nuclear DNA will be determined by flow cytometry of fresh material in different populations as this may affect the duration of the life cycle (Bennett et al, 1982).
Genotypic variation and phenotypic plasticity in reproductive traits will be determined by growing cloned plant-genotypes from different populations under a set of environmental (temperature, moisture) circumstances and measure generative traits. Differences in the response of genotypes or populations to these environmental conditions would indicate within- or among population variation in reproductive traits.
Data Set Citation
Dataset Originator/Creator: Mark Van de Wouw
Dataset Title: Molecular genetics Deschampsia antarctica
Dataset Series Name: Genetic configuration Deschampsia antarctica populations
Dataset Release Date: 2009-02-12
Dataset Release Place: Royal Netherlands Institute for Sea Research (NIOZ
Dataset Publisher: A.H.L. Huiskes
Start Date: 2003-01-01Stop Date: 2006-03-01
Paleo Temporal Coverage
ISO Topic Category
Data Set Progress
Role: TECHNICAL CONTACT
Phone: +31-317-480 916
Fax: +31-317-484 884
Email: Mark.vandewouw at wur.nl
P.O. Box 9101
Postal Code: 6700 HB
Country: THE NETHERLANDS
Role: DIF AUTHOR
Phone: +31 (0)113 577445
Fax: +31 (0)113 573616
Email: ad.huiskes at nioz.nl
Royal Netherlands Institute for Sea Research (NIOZ) P.O.Box 140
Province or State: Zeeland
Postal Code: 4400 AC
Country: The Netherlands
Journal of Biogeography, Volume 35, Issue 2 (p 365-376)
Download article at http://www3.interscience.wiley.com/cgi-bin/fulltext/119402414/PDFSTART
Creation and Review Dates
DIF Creation Date: 2009-02-12
Last DIF Revision Date: 2012-01-11