John Elix

Hybocarpone, a novel cytotoxic naphthazarin derivative from mycobiont cultures of the lichen Lecanora hybocarpa

Abstract Hybocarpone ( 1 ), a novel pentacyclic naphthazarin-derived dimer has been isolated from mycobiont cultures derived from the lichen Lecanora hybocarpa . The structure of hybocarpone ( 1 ) was established on the basis of 1D and 2D NMR spectroscopy. Its relative stereochemistry was predicted with the use of molecular modelling and confirmed by X-ray crystallographic analysis. Hybocarpone ( 1 ) was found to be a potent cytotoxin (IC 50 c 0.27 μM), active against the murine P815 mastocytoma cell line.

A simple and concise route to calothrixin B

Abstract A short and concise route to calothrixin B utilising Friedel–Crafts and lithiation reactions of readily available derivatives of quinoline and indole is described.

Differences in the composition of phenolics and fatty acids of cultured mycobiont and thallus of Physconia distorta

Abstract Germinated ascospores of Physconia distorta on an inorganic medium were grown on an enriched medium (Lilly–Barnet medium with 4% glucose), on which they produced swollen hyphae which included numerous lipid droplets. Secondary metabolites extracted from the cultured fungus were analyzed by high performance liquid chromatography and mass spectrometry. Analyses of superficial compounds established the presence of stearic, linoleic and oleic acids, and the corresponding triglycerides. Malonprotocetraric acid, several unknown pigments, and a series of fatty acids were detected as internal compounds. The qualitative and quantitative phenolic and fatty acid composition from the isolated fungal partner and lichenized thalli were different. Fatty acids were the main substances found by liquid chromatography in extracts of axenic cultures, while extracts from intact thalli contain phenolic acids as the main compounds. These results can be explained by metabolic differences as a result of the different available nutrients.

Austroparmelina, a new Australasian lineage in parmelioid lichens (Parmeliaceae, Ascomycota)

Parmelioid lichens form the largest monophyletic group within the Parmeliaceae, a family distributed worldwide. The genus Parmelina was described by Hale (1976a) accommodating species from both hemispheres. We have employed parsimony, Bayesian and maximum likelihood analyses of a combined data set of nu ITS, LSU and mt SSU rDNA sequences to (1) test the monophyly of Parmelina and (2) to elucidate the generic status and phylogenetic position of the Australasian species. Twenty-one new sequences were generated in this study. Our results provide evidence that Parmelina is polyphyletic and the species fall into two major well-supported groups (Groups I and II). The Australasian species of Parmelina and two species of Canoparmelia (C. pruinata and C. macrospora) form Group I, which is nested within the parmotremoid genera of Parmeliaceae, Parmelina species from the northern hemisphere including those from western North America and the Mediterranean basin form a monophyletic group (Group II), which is sister to the East Asian temperate genus Myelochroa. Morphological and chemical features were reevaluated considering this observed phylogeny. Some morphological features like lobe morphology, several traits in the excipulum and geography are useful in characterizing the monophyletic lineage of the Australasian Parmelina/Canoparmelina species. This lineage is described as the new genus Austroparmelina. Thirteen new combinations in the new genus are proposed.

Contributions to an epiphytic lichen flora of northwest North America: I. Eight new species from British Columbia inland rain forests

Abstract Recent surveys of the inland rain forests of British Columbia and adjacent regions have brought to light an unexpectedly rich epiphytic lichen flora, including several species apparently new to science. In the first of a series of papers, we describe eight species discovered during these surveys as new: Absconditella amabilis T. Sprib. (Ostropales), Bacidina contecta S. Ekman & T. Sprib., Biatora aureolepra T. Sprib. & Tønsberg, Biatora ligni-mollis T. Sprib. & Printzen (all Lecanorales), Collema coniophilum Goward (Peltigerales), Pertusaria diluta C. Björk, G. Thor & T. Wheeler (Pertusariales), Schaereria brunnea C. Björk, T. Sprib. & T. Wheeler (Ostropomycetidae incertae sedis) and Scoliciosporum abietinum T. Sprib. (Lecanorales). We also call attention to a ninth species, Bacidina sp. A, a poorly known and possibly undescribed colonizer of moribund cyanolichens. A majority of the above species appear to be confined to old-growth forests, while two (Biatora ligni-mollis and Schaereria brunnea) are currently known only from “antique” forests older than about 500 years. Many additional undescribed epiphytic lichens are known from inland rain forests, underscoring the need for further baseline biodiversity research in light of its ongoing disappearance as a result of resource extraction. In addition to the eight new species, we report Absconditella celata as new to North America, Absconditella lignicola as new to Canada and Montana, Bacidina chloroticula as new to British Columbia and Gyalideopsis piceicola as new to Montana.

A molecular phylogeny of the Lecanora varia group, including a new species from western North America

The phylogeny of the Lecanora varia group is inferred from ITS sequences using Bayesian and ML phylogenetic analysis methods. According to our data, usnic acid-containing, corticolous Lecanora species do not form a monophyletic group but occur in three major clades together with other groups of Lecanora and Protoparmeliopsis. The new combination Lecanora filamentosa (Stirt.) Elix & Palice is proposed. The new species Lecanora schizochromatica is described from northwestern North America. It produces atranorin as a major substance and is closely related to the morphologically and chemically similar L. filamentosa. The American Biatora pullula Tuck. is synonymised with Lecanora anopta Nyl., which is hereby reported for continental North America for the first time. The phylogenetic relationships between the major clades of Lecanora are still largely unresolved and require more intensive taxon and character sampling.

Species recognition and phylogeny of Thelotrema species in Australia (Ostropales, Ascomycota)

Species circumscriptions based on morphological data are difficult in crustose lichens with limited characters as they often show remarkable variability. An example is the genus Thelotrema s.str., a speciose genus of mostly tropical lichens. Morphological studies on Australian Thelotrema spp. were accompanied by a phylogenetic analysis of mt SSU rDNA sequence data of 19 species, including 25 newly obtained sequences. We performed maximum parsimony and Bayesian phylogenetic analyses of 50 samples, representing 25 species. Our results indicate that more species need to be accepted in Thelotrema than previously thought. Subtle morphological differences were found to be associated with independent lineages in the phylogenetic trees. Furthermore, monophyly of Thelotrema s.str. is strongly supported. On the basis of the corroboration of morphological evidence by molecular data, the new species Thelotrema capetribulense Mangold, T. crespoae Mangold, Lumbsch & Elix, T. oleosum Mangold, and T. pseudosubtile Mangold are described. The new combinations Chapsa phlyctidioides (Mull.Arg.) Mangold and Thelotrema defossum (Mull.Arg.) Mangold are proposed.

Phenotypic disparity and adaptive radiation in the genus Cladia (Lecanorales, Ascomycota)

Phylogenetic relationships of the genera Cladia, Heterodea and Ramalinora were reconstructed using a combined dataset of ribosomal nuclear ITS and LSU and mitochondrial SSU, and protein-coding Mcm7 DNA sequences. Maximum likelihood and Bayesian analyses strongly supported a monophyletic group in which the species of the foliose genus Heterodea and the crustose genus Ramalinora were nested within the fruticose genus Cladia. Alternative hypothesis testing rejected an independent status of Ramalinora. We tested the hypothesis that an adaptive radiation led to the morphological disparity found in the Cladia clade. Gamma-statistics indicated a significantly disproportional clustering of origins of extant lineages at the base of the Cladia clade and lineage-through-time plots were also consistent with the hypothesis of an adaptive radiation at the base of the Cladia clade. Ancestral-range reconstructions supported an origin of Cladia and the three major lineages within Cladia in Australia. On the basis of these results, we propose an evolutionary hypothesis for the genus. The results suggest that processes of adaptive radiation of the ancestor of Cladia in Australia led to the morphological disparity in the extant taxa, and that the broad distribution of some extant species is due to subsequent long-distance dispersal.

The genus Karoowia (Parmeliaceae, Ascomycota) includes unrelated clades nested within Xanthoparmelia

Thallus morphology has traditionally played a major role in the classification of lichenised fungi. We have used a combined dataset of nuITS, nuLSU and mtSSU rDNA sequences to evaluate the phylogenetic relationships between the subcrustose genus Karoowia and the mostly foliose genus Xanthoparmelia. Our phylogenetic analyses using maximum parsimony, maximum likelihood and a Bayesian approach show that Karoowia species do not form a monophyletic group but cluster in different clades nested within Xanthoparmelia. The monophyly of Karoowia either as a separate clade from Xanthoparmelia, or nested within Xanthoparmelia is significantly rejected using alternative hypothesis testing. These results suggest that the usefulness of the phenotypic features used to define Karoowia has been overestimated because the subcrustose growth form has evolved independently in several clades within Xanthoparmelia. Other characters used to circumscribe Karoowia, such as the presence of cylindrical conidia, also occur in Xanthoparmelia, and the differences in rhizine morphology are minimal. Consequently, we propose to reduce Karoowia to synonymy with Xanthoparmelia. The enlarged genus is characterised by the presence of Xanthoparmelia-type lichenan in the hyphal cell walls and the presence of an arachiform vacuolar body in the ascospores. Fifteen new combinations in Xanthoparmelia and the new name Xanthoparmelia mucinae for Karoowia squamatica are made.

Triterpene chemosyndromes and subtle morphological characters characterise lineages in the Physcia aipolia group in Australia (Ascomycota)

Abstract Species delimitation in lichens of the Physcia aipolia group in Australia has been studied based on thalline morphology (lobe width, upper surface pruinosity) and medullary triterpene chemistry as main character complexes. Previous treatments have utilised the presence or absence of atranorin and zeorin in the medulla as useful discriminators, but have neglected utilising the diversity of medullary triterpenes for taxonomic purposes. We have now tested the phylogenetic patterns of distribution of subtle morphological characters and terpenoid chemistry by means of molecular phylogenetic analysis of nuclear ITS and mitochondrial SSU rDNA sequences. Our analysis supports triterpene chemosyndromes and subtle morphological characters for the distinction of distinct lineages. Three new species are described for Australia, P. austrostellaris Elix, P. littoralis Elix and P. tropica Elix. In addition, the detailed chemical variation of species within the group is documented and three major chemosyndromes of triterpenes have been identified.