Jan-Eric Mattsson

Ribosomal DNA and β-tubulin data do not support the separation of the lichens Usnea florida and U. subfloridana as distinct species

The lichens Usnea florida and U. subfloridana have since long been recognised as distinct species. They show many similarities in morphology, but have different reproductive strategies. Usnea flori ...

Evolution of complex symbiotic relationships in a morphologically derived family of lichen-forming fungi.

We studied the evolutionary history of the Parmeliaceae (Lecanoromycetes, Ascomycota), one of the largest families of lichen-forming fungi with complex and variable morphologies, also including several lichenicolous fungi. We assembled a six-locus data set including nuclear, mitochondrial and low-copy protein-coding genes from 293 operational taxonomic units (OTUs). The lichenicolous lifestyle originated independently three times in lichenized ancestors within Parmeliaceae, and a new generic name is introduced for one of these fungi. In all cases, the independent origins occurred c. 24 million yr ago. Further, we show that the Paleocene, Eocene and Oligocene were key periods when diversification of major lineages within Parmeliaceae occurred, with subsequent radiations occurring primarily during the Oligocene and Miocene. Our phylogenetic hypothesis supports the independent origin of lichenicolous fungi associated with climatic shifts at the Oligocene-Miocene boundary. Moreover, diversification bursts at different times may be crucial factors driving the diversification of Parmeliaceae. Additionally, our study provides novel insight into evolutionary relationships in this large and diverse family of lichen-forming ascomycetes.

Evolution and phylogeny of cetrarioid lichens

TheAcharian genusCetraria has not been scrutinised in the same way as the genusParmelia in terms of circumscription of segregate genera. A few generic names have been introduced, but mainly in checklists without any real indication of what these names stand for. After a detailed investigation of characters in the apothecia, conidiomata, anatomical structures, as well as morphology and secondary chemistry, it is clear that several, more or less distinctive, phylogenetic lines exist among taxa which earlier were accommodated inCetraria. Some of these distinctive phylogenetic lines are distinguished by ascus characters: (1) clavate asci with a small axial body, an apical ring structure in the tholus and ellipsoid ascospores; (2) uniseriate asci with a large axial body and globose ascospores; and (3) taxa with broadly clavate asci with a large axial body and ellipsoid ascospores. Sixty-three character states were studied and results from the character analyses were evaluated by cladistic analysis against 43 examined terminal taxa. Seven further taxa were included in one analysis. Results from the cladistic analyses give rather strong support for a new systematic treatment of at least certain groups in the cetrarioid lichens. A formal systematic arrangement is not made here but will be presented elsewhere. The characters investigated are illustrated in 78 half tone pictures and one line drawing. Five cladograms are presented.

PHYLOGENY OF THE PARMELIACEAE— DNA DATA VERSUS MORPHOLOGICAL DATA

In order to identify monophyletic groups within the familyParmeliaceae, eleven taxa (Bryoria capillaris,Cetraria islandica,Evernia pruniastri,Hypogymnia physodes,Parmelia saxatilis,Platismatia glauca,Pleurosticta acetabulum,Usnea florida,Vulpicida juniperina,V. pinastri, andXanthoparmelia conspersa) were studied using newly produced nuclear rDNA sequence data from the ITS and 5·8S regions. The resulting evolutionary hypothesis was compared with results from previous phylogenetic analyses based on anatomy, morphology, and chemistry. The outcome of this comparison does not support the earlier proposed phylogenies but is not stable enough for identifying monophyletic groups, with one exception. The results indicate a close relationship betweenCetrariaandVulpicida, which is contradictory to previous published analyses. The variation in ascus structures in theParmeliaceaeis discussed and it is questioned whether the earlier distinguished ‘ forms ’ of ascus types represent synapomorphies, if they are based on poorly supported analyses, or if they are exaggerations of relatively slight variation in shape. Further interpretations of the results are discussed and areas of future studies based on DNA-data are suggested.

A multi-gene study of the phylogenetic relationships of the Parmeliaceae

Three hypotheses of the phylogeny of the lichenized Parmeliaceae are constructed, using sequences of the nuclear ribosomal gene cluster (SSU, ITS, 5.8S rDNA) from Bryonia capillaris, Cetraria islan ...

An exceptional group-I intron-like insertion in the SSU rDNA of lichen mycobionts

Abstract An exceptional group-I intron-like insertion at position 940 of the nuclear small subunit rDNA is found in lichen mycobionts of the families Parmeliaceae and Lecanoraceae. This shared insertion site is exceptional as it follows a G. Although several features of the self-splicing Tetrahymena intron are missing, the conserved structure of the presumed core region indicates that the new intron-like insertion, which is missing in mature transcripts, is not part of a silenced ribosomal repeat. It is unlikely that the new insertion is horizontally transferred from the adjacent position 943. A phylogenetic analysis indicates congruence with lichen phylogeny and suggests that the insertion has been vertically inherited.

The lichen genera Arctocetraria, Cetraria, and Cetrariella (Parmeliaceae) and their presumed evolutionary affinities

The lichen genera Arctocetraria, Cetraria, and Cetrariella (Parmeliaceae) and their presumed evolutionary affinities

Protein banding patterns in the Ramalina siliquosa group

The value of primary chemical compounds correlated with known secondary chemistry and morphological variation within the Ramalina siliquosa group has been investigated. A hundred specimens were collected on two different occasions from 13 different populations on the Swedish west coast during April 1984. Protein extracts were prepared from 27 on secondary constituents identified and morphologically analysed populations. The protein bandings were performed by means of isoelectric focusing. Twenty-two different banding patterns were analysed since two were destroyed during preparation and three others yielded weak patterns. The results indicated that three different banding pattern types could be discerned: type A originated from material containing norstictic acid, stictic acid, norstictic acid in combination with stictic acid and on acid-deficient material; type B originated from material containing salazinic acid or salazinic acid in combination with protocetraric acid; and type C originated from material containing salazinic acid, protocetraric acid, salazinic acid in combination with protocetraric acid or on acid-deficient material. Material of banding type A belonged morphologically to R. cuspidata (Ach.) Nyl. and material of banding types B and C to R. siliquosa (Hudson) A. L. Smith. Seasonal and developmental factors can, however, affect the production of both primary and secondary constituents. Since there are no obvious morphological differences between the different chemical races within R. siliquosa s. str. and as material of salazinic acid in combination with protocetraric acid yielded both type B and type C banding patterns, the results do not support a taxonomy in the R. siliquosa group recognizing more than two species. (Less)

Genetic variation in relation to substratum preferences of Hypogymnia physodes

Genetic variability and its relationship to substratum preferences within and among populations of the sorediate foliose lichen Hypogymnia physodes was investigated using sequence variation in the ...

Rapid changes in the epiphytic macrolichen flora on sites in southern Sweden

A relatively quick and simple method is presented for monitoring changes in distribution and in site and substratum preferences of epiphytic macrolichens; the method also records the natural turnov ...