Effects of outcrossing in fragmented populations of the primarily selfing forest herb <Emphasis Type="Italic">Geum urbanum</Emphasis> |
| |
Authors: | K Vandepitte O Honnay H Jacquemyn I Roldán-Ruiz |
| |
Institution: | (1) Laboratory of Plant Ecology, Biology Department, Katholieke Universiteit Leuven (KULeuven), Kasteelpark Arenberg 31, 3001 Heverlee, Belgium;(2) Plant Sciences Unit, Growth and Development, Institute for Agricultural and Fisheries Research (ILVO), Caritasstraat 21, 9090 Melle, Belgium |
| |
Abstract: | In fragmented landscapes, small populations may be subjected to inbreeding or genetic drift. Gene flow is expected to alleviate
the burden of deleterious mutations in such populations. The beneficial effects of outcrossing may, however, depend on life
history characteristics such as the species’ breeding system. Frequent selfing is expected to purge (sub)lethal alleles and
mitigate inbreeding depression, at least if the load of mildly deleterious mutations has not accumulated through genetic drift
in populations with a small effective size. Gene-inflow from distant source populations can cause outbreeding depression due
to genomic incompatibilities. We tested these predictions using highly fragmented populations of the self-compatible forest
herb Geum urbanum. Assessment of mating system parameters using microsatellite markers inferred high selfing rates (92.5%), confirming the
predominantly self-fertilizing character of the study species. We conducted experimental pollinations with self and outcross
pollen collected from populations at different distances from the target populations. There were no significant signs of inbreeding
depression, even in very small target populations. Except for a minor negative effect on the germination rate for the long-distance
crosses, we found no effects of outbreeding on fitness estimates. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|