Peterson, Angela , Bartish, Igor V. , Peterson, Jens .
Genetic and fitness consequences of habitat fragmentation on Anthericum liliago populations.
THE genetic and fitness consequences of habitat fragmentation of the rare plant Anthericum liliago (Anthericaceae) were examined. We investigated 10 A. liliago populations (Saxony-Anhalt, Germany) which differ considerably in the number of ramets (from about 100 to over 2 million), the population areas (17.5 to over 30000 m2) and the density of plants (0.17 to 83.5 ramets per m2) within a population. With the RAPD analysis of 145 A. liliago ramets, 238 fragments could be amplified, of which 42.86 % were polymorphic. Population genetic structure was found both between (59 %) and within (41 %) populations. The genetic diversity of an A. liliago population is highly positively correlated with its population size. The correlation between geographic and genetic distances for subpopulations is mostly determined by a relatively short-range (up to about 20 km) gene flow process, whereas over greater distances the gene flow is more sporadic. Fine-scale structuring may have been caused by limited seed and pollen dispersal and a mixed mating system permitting a great degree of selfing. In very small A. liliago populations, poor genetic diversity has no connection with a loss of reproductive capacity. The reproductive output (seeds per ramet) was only highly correlated with the proportion of flowering ramets in a population, but not with population size and genetic diversity. The main pollinators of A. liliago are the syrphid Merodon rufus as well as wild bees. The pollinator assembly of an A. liliago population depends on its population size and its habitat type. In very small A. liliago populations, which grow in isolated grassland patches and lack attractive flowers, neither the poor genetic diversity, nor the absence of the main pollinators cause a loss of reproductive capacity considering fruit set, seed set and germination rates.
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1 - Martin Luther University Halle/Wittenberg, Biozentrum, Weinbergweg 22, Halle (Saale), D-06120, Germany
2 - Swedish Museum of Natural History, Department of Phanerogamic Botany, Box 50007, Stockholm, 104 05, Sweden
3 - State Office for Environmental Protection of Saxony-Anhalt, Department of Nature Conservation, Reideburger Str. 47, Halle (Saale), D-06116, Germany
population genetic structure
Presentation Type: Oral Paper:Papers for Topics
Date: Monday, July 31st, 2006
Time: 10:15 AM