Abstract Detail

Bryological and Lichenological Section/ABLS

Pohjamo, Maria [4], Korpelainen, Helena [4], Kalinauskaite, Nijole [1], Fagersten, Reino [3], Laaka-Lindberg, Sanna [2].

Genetic diversity of two rare bryophyte species possessing different reproductive systems.

We have investigated the genetic structure of populations in two habitat specialist species which possess different reproductive systems. Trichocolea tomentella (Ehrh.) Dumort is a dioecious hepatic which reproduces mainly by vegetative propagation. Although gametangia are observed, sporophytes are extremely rare. T. tomentella occupies swampy forests and spring areas. We have collected material from 20 populations of different sizes in a wide geographical range including Finland, Lithuania, UK and Canada. Another species studied is a monoecious moss, Plagiomnium drummondii (Bruch. & Schimp.) T.J.Kop., which has frequent sexual reproduction. P. drummondii is a habitat specialist which occupies o­nly shady, herb-rich forests with calcareous ground. We have sampled all known populations of P. drummondii located in Eastern Finland in its o­nly area of occurrence in Finland, and also four populations located in western Russia. Both T. tomentella and P. drummondii are known to be declining due to the destruction of their habitats. This may cause a loss of genetic diversity and reduce the fitness of the species in a long term.
The genetic structure and the level of gene flow have been investigated by conducting DNA fingerprinting studies with non-specific ISSR and RAPD markers. The advantage of these methods is that no previous knowledge of the genomes is needed. The amplifications resulted in a number of polymorphic markers that revealed that the populations of T. tomentella and P. drummondii contain a fair amount of genetic variation. Preliminary results reveal the presence of considerable geographical differentiation in T. tomentella while no genetic subdivision was detected in the populations of P. drummondii indicating substantial gene flow as a result of frequent spore production.

1 - University of Vilnius, Department of Botany and Genetics, Ciurionio 21/27, 0049 Vilnius, , Lithuania
2 - Lammi Biological Station, Pääjärventie 320, FI-16900 Lammi, , Finland
3 - Natural History Museum of Kuopio, Myhkyrinkatu 22, Kuopio, FIN-70100, Finland
4 - University of Helsinki, Department of Applied Biology, P.O. Box 27, Helsinki, FIN-00014, Finland

Keywords:
boreal forests
DNA fingerprinting
habitat fragmentation
Trichocolea tomentella
Plagiomnium drummondii
population genetics.

Presentation Type: Paper
Session: 35-5
Location: Ballroom 3 (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 3:00 PM
Abstract ID:428