Per Paulsrud
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Per Paulsrud has a total of 2 co-authors. Here are the top co-authors by number of shared publications:
Jouko Rikkinen
Department of Applied Biology, PO Box 27, FIN‐00014 University of Helsinki, Finland
1 shared publication- Peter Lindblad
Microbial Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
1 shared publication
Latest Publications
- 1 October 2001
- Published by Wiley in New Phytologist
- Vol. 152 (1) , 117-123
Field investigations on cyanobacterial specificity in Peltigera aphthosa
• Possibilities of introducing new cyanobacterial strains into established lichen symbioses were examined by manipulating thalli of Peltigera aphthosa and by using the trnL (UAA) intron to identify specific cyanobacterial strains. • P. aphthosa has Nostoc symbionts in cephalodia on the upper surface of the thallus. In three different P. aphthosa populations, each consisting of seven thalli, all cephalodia were experimentally removed. The manipulated lichens were then inoculated with known strains of cultured cyanobacteria and left to develop new cephalodia. After a summer in the field the lichens were harvested and the strain identities of cyanobacterial symbionts in 80 newly formed cephalodia were determined. All epiphytic colonies of free-living cyanobacteria found were also analysed. • Foreign cyanobacteria were not readily incorporated into established P. aphthosa thalli. All newly formed cephalodia contained the same intron sequence, which was identical to that found in the removed cephalodia. At least two inoculated Nostoc strains were able to survive as epiphytic colonies on experimental thalli. Both strains had originally been isolated from bipartite Peltigera species. • Results indicate that associations between cyanobacteria and lichen-forming fungi can be very specific and stable, which contrasts with the general view that cyanobacterial symbioses are rather unspecific.
- 1 October 2001
- Published by Wiley in New Phytologist
- Vol. 152 (1) , 117-123
Field investigations on cyanobacterial specificity in Peltigera aphthosa
• Possibilities of introducing new cyanobacterial strains into established lichen symbioses were examined by manipulating thalli of Peltigera aphthosa and by using the trnL (UAA) intron to identify specific cyanobacterial strains. • P. aphthosa has Nostoc symbionts in cephalodia on the upper surface of the thallus. In three different P. aphthosa populations, each consisting of seven thalli, all cephalodia were experimentally removed. The manipulated lichens were then inoculated with known strains of cultured cyanobacteria and left to develop new cephalodia. After a summer in the field the lichens were harvested and the strain identities of cyanobacterial symbionts in 80 newly formed cephalodia were determined. All epiphytic colonies of free-living cyanobacteria found were also analysed. • Foreign cyanobacteria were not readily incorporated into established P. aphthosa thalli. All newly formed cephalodia contained the same intron sequence, which was identical to that found in the removed cephalodia. At least two inoculated Nostoc strains were able to survive as epiphytic colonies on experimental thalli. Both strains had originally been isolated from bipartite Peltigera species. • Results indicate that associations between cyanobacteria and lichen-forming fungi can be very specific and stable, which contrasts with the general view that cyanobacterial symbioses are rather unspecific.