<p>Small populations are facing a particular risk of extinction due to a lack of appropriate genetic diversity and associated negative effects, factors dealt with in the discipline of conservation genetics. Many orchid species exhibit characteristics that make them a perfect study object in the scope of conservation genetics. The aim with this thesis was to investigate genetic structure at different levels in two orchid species <i>Gymnadenia conopsea</i>, geographically widespread, although diminishing and <i>G. odoratissima</i> with a long history of being rare. Microsatellite markers, developed in and used in studies of <i>G. conopsea</i> were also used in the study of <i>G. odoratissima</i>.</p><p>Populations of <i>G. conopsea</i> expressed high levels of genetic variation and a certain amount of gene flow, although investigated mating pattern in a small population indicated non-random mating among individuals, with the majority of pollen exchange between near neighbours, and noticeable levels of geitonogamous pollinations. Further a pronounced year to year variation in flowering frequency among individuals was found. </p><p>It was also discovered that flowering time variants (early and late) within the species <i>G. conopsea</i> were highly differentiated and seem to have had a more ancient historical separation than the separation between the two different species, <i>G. conopsea</i> and <i>G. odoratissima. </i></p><p>Levels of genetic variation in the rare congener, <i>G. odoratissima</i> differed between island and mainland populations where the more numerous island populations expressed larger levels of genetic variation and were less differentiated compared to the few remaining and genetically depauperated mainland populations.</p><p>Uppsala University Library, Box 510, 75120, Uppsala, Sweden </p>
| Identifer | oai:union.ndltd.org:UPSALLA/oai:DiVA.org:uu-3305 |
| Date | January 2003 |
| Creators | Gustafsson, Susanne |
| Publisher | Uppsala University, Department of Conservation Biology and Genetics, Uppsala : Acta Universitatis Upsaliensis |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Doctoral thesis, comprehensive summary, text |
| Relation | Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1104-232X ; 799 |
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