Evolution of Inbreeding and Outcrossing in Ferns and Fern-Allies
Article first published online: 3 FEB 2005
Plant Species Biology
Volume 5, Issue 1, pages 1–11, June 1990
How to Cite
Soltis, P. S. and Soltis, D. E. (1990), Evolution of Inbreeding and Outcrossing in Ferns and Fern-Allies. Plant Species Biology, 5: 1–11. doi: 10.1111/j.1442-1984.1990.tb00187.x
- Issue published online: 3 FEB 2005
- Article first published online: 3 FEB 2005
- Received September 10, 1989. Accepted April 20, 1990.
- mating systems;
- inbreeding depression;
- population structure;
- homosporous pteridophytes
Abstract Mating systems of 18 species of homosporous ferns follow a bimodal distribution, similar to that observed for seed plants (Schemske and Lande, 1985). Most species are highly outcrossing, a few are inbreeding, and two species examined to date have mixed mating systems. Equisetum arvense and several species of lycopods are also highly outcrossing. Several mechanisms, including inbreeding depression, antheridiogen, and ontogenetic sequences that result in effectively unisexual gametophytes, promote outcrossing in homosporous ferns and perhaps other homosporous pteridophytes as well. In some species of homosporous ferns, selection has favored the evolution of inbreeding as an adaptation for colonization. High levels of intra- and interpopulational gene flow via spore dispersal, coupled with high levels of intergametophytic crossing, generally lead to genetically homogeneous populations and species of homosporous ferns. However, rock-dwelling ferns and ferns from xeric habitats may exhibit significant population genetic structure due to physically patchy habitats. Reticulate evolution in homosporous ferns may be enhanced by high levels of intergametophytic crossing.