Growth rates in vegetative and reproductive tissue of Parmelia cumberlandia after relocation to a... more Growth rates in vegetative and reproductive tissue of Parmelia cumberlandia after relocation to a new environment. Canadian Field-Naturalist 91(2): 134-140. Abstract. A large colony of the lichen Parmelia cumberlandia (Gyeln.) Hale and its rock substrate were subdivided by means of a diamond saw and the portions relocated at different sites. After 1 year, vegetative growth and trends in the production of apothecial tissue were observed. The annual growth rates recorded for the vegetative part of the thallus of P. cumberlandia were considerably higher than for any other species of Parmelia reported previously and are among the highest reported for any lichen. In sections of the thallus transported to new and slightly more southerly locations, previously existing apothecia expanded to a greater extent, and new apothecia developed more frequently, than in the control location.
Archives of Environmental Contamination and Toxicology, Aug 1, 2003
The influence of copper was assessed on wild and tolerant strains of the lichen photobiont Trebou... more The influence of copper was assessed on wild and tolerant strains of the lichen photobiont Trebouxia erici and shown to have multiple toxic effects. Addition of 4 mM copper chloride into Trebouxia media reduced growth rates of the wild type to less than 1% of control levels. It also injured cell membranes, inhibited dehydrogenase activity, altered pigment composition, and reduced activity of photosystem II. Membrane damage was assessed through measuring electrical conductivity and potassium content, dehydrogenase activity by degree of conversion of 2,3,5-triphenyl tetrazolium chloride to red triphenylformazan, and functioning of PS II by chlorophyll a fluorescence. In respect to most parameters the tolerant strain was usually less affected by copper than the wild strain and, in some cases, not at all. We demonstrated by inductively coupled plasma atomic emission spectrometry and energy-dispersive X-ray microanalysis that enriched copper in the medium resulted in increased uptake by both wild and tolerant photobiont cells, but extracellular concentrations were significantly higher in the tolerant strain. This suggested that, at least in vitro, extracellular deposition was a mechanism of copper tolerance.
Free proline accumulation has been observed in response to heavy metal stress in plants including... more Free proline accumulation has been observed in response to heavy metal stress in plants including algae, however nothing is known about its role in copper sensitivity or copper tolerance in lichen photobionts. Copper uptake, potassium efflux and free proline accumulation were determined in copper-enriched liquid cultures of wild-type Trebouxia erici as well as in copper-tolerant strain. By using inductively coupled plasma atomic emission spectrometry we found that the highest intracellular copper uptake from 2 mM copper media occurred within 4 h in both strains, but significantly less was accumulated by the tolerant strain. The copper-tolerant strain exhibited significantly more intracellular proline and significantly less potassium efflux than the wild strain. By 24 h differences between strains in intracellular copper diminished, as concentrations in both strains reached their highest levels. At the same time proline accumulations decreased significantly. Growth, pigment content, chlorophyll a degradation and chlorophyll a fluorescence were decreased by high copper concentration in the agar media after 2 weeks of cultivation, more pronounced in wild-type of T. erici. Adding proline alleviated the toxic effects of copper in both strains, but markedly so in the case of the tolerant strain.
A significant negative correlation was found between the quantity of acetone-extractable phenolic... more A significant negative correlation was found between the quantity of acetone-extractable phenolic compounds and the degree of enzyme polymorphism in eight eastern North American populations of Umbilicaria americana. In sites at higher elevations, where UV irradiance was more intense, phenolic levels were significantly lower and within-stand enzyme variability significantly greater than in low elevation sites. Similarly, the phenolic content of thalli collected in Ontario, Canada, over a 16-month sampling period was negatively correlated with mean monthly UV-B irradiance.
Old-growth forests are declining throughout eastern North America, especially toward the northern... more Old-growth forests are declining throughout eastern North America, especially toward the northern limit of the deciduous formation where gently undulating topography and milder climate especially encourage human activity. Remnants exist, but do they retain the defining characteristics of the original vegetation? The objective was to marshal information required to answer this question, and toward this objective we assessed vegetation in a small 1 ha remnant of maple-beech forest with no history of past logging and compared it to well known and larger old-growth areas in the region. We used Curtiss (1959) Point Quarter method to provide full quantitative data for trees, saplings, shrub and herbs. Size class distribution of trees and successional status of the stand were assessed. As a general conclusion, we found that tree species richness of our remnant was higher than most recognized large old-growth forests and, while the herbaceous understorey was poorer in species than larger tracts, it exhibited three provincially rare species. Furthermore, the successional status and structural complexity of the remnant were typical of old-growth forests. In overall comparative terms, the remnant was found not be an outlier when ordinated with larger forests. It thus is safe to conclude that this remnant constitutes an ecological benchmark well worth protection, despite its limited size. Abbreviations: asl-above sea level; BABH-basal area 1 m above ground; DBH-diameter 1 m above ground; DCA-detrended correspondence analysis; DF-density-frequency index or sum of relative frequency and relative density; DFD-sum of relative density; relative frequency and relative dominance also called importance value;
Ultraviolet light is known to alter thallus concentrations of lichen phenolics, thus attempts wer... more Ultraviolet light is known to alter thallus concentrations of lichen phenolics, thus attempts were made to assess photostability. Lichen products extracted from 14 lichen species were applied to thin-layer chromatography (TLC) plates, exposed to high intensity UV-A/B and developed in suitable solvents. Banding patterns of extracts containing gyrophoric acid, lecanoric acid and tenuiorin were not altered by UV, but patterns of species containing usnic acid, atranorin, barbatic acid and didymic acid changed visibly. Thin-layer chromatography, gas chromatography and mass spectroscopy showed that usnic acid is broken down by UV into photoproducts with molecular weights lower than usnic acid itself. However, banding patterns of extracts from intact thalli exposed to UV were not visibly different from unexposed controls for any of the four species tested, Cladonia uncialis, Cladonia rangiferina, Peltigera aphthosa and Umbilicaria mammulata. Nevertheless, quantitative analysis of Cladonia uncialis showed consistently lower-than-control amounts of usnic acid in irradiated subsamples of all whole thalli tested, suggesting that degradation probably occurred. Live air-dried material consistently maintained control levels of phenolics after irradiation, but hydrated subsamples tended to show decreased concentrations of usnic acid.
Cellulose-acetate filter disks were found convenient for the cultivation of lichen mycobionts and... more Cellulose-acetate filter disks were found convenient for the cultivation of lichen mycobionts and artificial re-synthesis of lichens, and using this method of culture we tested the effects of acidification on Cladonia cristatella Tuck. Mycobionts subjected to short-term strongly acidic conditions showed decreased formazan production compared to colonies grown at optimal pH 5.0. Disk-supported synthetic lichens grown at pH 3.0 or 5.0 exhibited no significant differences in pigment chemistry or photosynthetic efficiency compared to those at pH 7.0, but all of these parameters changed at pH 1.5. Chlorophyll a integrity significantly decreased under all treatments involving acidified water, with the highest amount of degradation at pH 1.5. At pH 1.5, significantly decreased concentrations of both -carotene and total carotenoids were observed. A significant decrease in chlorophyll a fluorescence was also shown at pH 1.5.
Transplantation to new locations is used widely to propagate horticultural and agricultural speci... more Transplantation to new locations is used widely to propagate horticultural and agricultural species but is also promoted as a means of relocating whole communities that stand in the way of development. It may be used as well to move vegetation from the field for experimentation under controlled conditions. Transplantation has not in the past been considered a reliable means of conserving threatened species or reproducing functional characteristics of natural communities, and has been regarded by many as highly ineffective. However, its potential must now be reexamined because of the many recent transplant attempts as well as advances in related fields. Recent trials illustrate that individual endangered species are still particularly difficult to transplant and displaced multi-species sods are almost always changed in the process. Exact reconstruction of communities from individual components is next to impossible because the full complement of species, including critical microbial components, is almost never known. Owing to a limited understanding of phenology, reproduction, functional roles, and interrelationships among constituent microbes, cryptogams, vascular plants, and fauna, transplants may be placed into sites with both biological and physical insufficiencies. Genetic diversity may be lost or, if genotypes from diverse sources are mixed, outbreeding depression may result. Recent advances in soil science, microbial ecology, and population genetics have in some cases improved the effectiveness of transplantation, but new insights mainly permit a fuller appreciation of the causes of failure. Home-site advantage has been demonstrated, and habitat protection appears to be the best and perhaps only reliable way of preserving intact natural communities and rare species. Furthermore, experimentation with vegetational mats under controlled conditions may have little relevance to natural ecosystems.
Energy-dispersive X-ray microanalysis and X-ray mapping were used to study metal uptake by the li... more Energy-dispersive X-ray microanalysis and X-ray mapping were used to study metal uptake by the lichens Lecidea lithophila and Rhizocarpon oederi growing on centuries old copper mine spoil heaps in Špania Dolina, Slovakia. Mineral waste derived from historical extraction of copper was still rich in the heavy metals iron and aluminum, while copper was not detectable. In apothecia of both species there was, as expected, significantly more C than in the substrate but the same levels of O, Na and Mg. The elements Al, Si, and K were present in apothecia of both lichen species, but in significantly lower concentrations than in the substrate. The weight percent of Fe for L. lithophila ascocarps was also significantly lower than the substrate, but Cu concentrations were higher. Elemental composition of the vegetative part of thalli, determined only in L. lithophila, did not differ significantly from that of the substrate.
A significant negative correlation was found between the quantity of acetone-extractable phenolic... more A significant negative correlation was found between the quantity of acetone-extractable phenolic compounds and the degree of enzyme polymorphism in eight eastern North American populations of Umbilicaria americana. In sites higher elevations, where UV irradiance was more intense, phenolic levels were significantly lower and within-stand enzyme variability significantly greater than in low elevation sites. Similarly, the phenolic content of thalli collected in Ontario, Canada, over a 16-month sampling period was negatively correlated with mean monthly UV-B irradiance.
The foliose lichen Umbilicaria americana Poelt & Nash was exposed to spectrally altered r... more The foliose lichen Umbilicaria americana Poelt & Nash was exposed to spectrally altered radiation in three growth chamber experiments and one field experiment. After 1 week in growth chambers the phenolic content (% w/w) increased significantly under a spectral band including visible light and UV-A, and the increase was greater when intensity was higher. Under exposure to both UV-A and UV-B the concentration of phenolics was lower than with UV-A alone and, depending on dosage, approached or achieved control levels. In a population of U. americana on a vertical rock face, the interaction between filter treatments and collection dates had a highly significant effect on phenolic levels (P = 0.01). In thalli protected from UV-B, phenolic levels were higher than in those exposed to natural sunlight in June and October, but the same response was not observed in July and August. Thallus groupings covered by filters that admitted both UV-B and UV-A accumulated less phenolics than controls in August, but on other sampling dates contained the same concentrations. Key words: Umbilicaria americana, UV-A, UV-B, depsides, tridepsides.
... Abstract. Cellulose-acetate disks were found convenient for the cultivation of lichen myco-bi... more ... Abstract. Cellulose-acetate disks were found convenient for the cultivation of lichen myco-bionts and artificial resynthesis and culture of the lichen Cladonia cristatella. ... Page 3. 2003] BACKOR & FAHSELT: LICHEN CULTURE SUBSTRATE 441 160 - 140 a E 120 ' 100 ...
... and one of P. rigida Lynge were sampled. ... Although earlier numerical taxonomists favored t... more ... and one of P. rigida Lynge were sampled. ... Although earlier numerical taxonomists favored the use of large numbers of characters, it has more recently been shown (Wishart, 1969; Orloci, 1973, 1976) that characters contributing mini-mally to the classification are harmful rather ...
... 1982; Fahselt et al. 1995; Jeran et al. 1995). ... Air-dried li-chens that are rewetted exper... more ... 1982; Fahselt et al. 1995; Jeran et al. 1995). ... Air-dried li-chens that are rewetted experience a period of accelerated respiration, but after approximately 10 hr, normal levels of respiration are resumed (Smith & Molesworth 1973). ...
Thalli from a population of Cladonia cristatella Tuck. were sorted according to mor- phological c... more Thalli from a population of Cladonia cristatella Tuck. were sorted according to mor- phological characters and the ten most common types were determined on the basis of podetial biomass. From a large podetial sample of each morphotype which was available in sufficient quan- tity, crude protein extracts were prepared and subjected to isoelectricfocusing. Comparisons were made among common morphological variants on the basis of gels stained for the activity of 12 enzymes. A few of the common morphotypes were sampled more intensively in order to provide an indication of possible enzyme polymorphism within morphological forms. There was little evidence of variation in dehydrogenase enzymes among morphotypes but there were differences with respect to esterase and acid and alkaline phosphatases. However, variation in enzyme forms was also observed within morphotypes. There was, thus, no indication of unusual differences among mor- phological variants of C. cristatella and also no evidence to suggest that distinct morphological forms are diverging from one another in the population.
... Türk, Elfie Stocker-Wörgötter. (2008) Production and Bioactivity of Common Lichen Metabolites... more ... Türk, Elfie Stocker-Wörgötter. (2008) Production and Bioactivity of Common Lichen Metabolites as Exemplified by Heterodea muelleri (Hampe) Nyl.. Journal of Chemical Ecology 34:2, 113-120 Online publication date: 1-Feb-2008. N. Valencia-Islas, A. Zambrano, JL Rojas. ...
The foliose lichen Parmelia aurulenta Tuck. (Parmeliaceae) was examined using scanning electron m... more The foliose lichen Parmelia aurulenta Tuck. (Parmeliaceae) was examined using scanning electron microscopy and transmittance electron microscopy. The algal component was identified as Trebouxia and the physical relationship between algal cells and fungal hyphae was studied. An impression of the three-dimensional relationship between the two symbionts was obtained with the scanning electron microscope, and the sites of extensive crystal deposition were identified.
... CECILIA HAGEMAN AND DIANNE FAHSELT Department of Plant Sciences, University of Western Ontari... more ... CECILIA HAGEMAN AND DIANNE FAHSELT Department of Plant Sciences, University of Western Ontario, London, Ontario N6A 5B7, Canada ... Staining recipes for IDH, 6PG and GDH were from Adams and Joly (1980), G6P, EST and ALP from Brewer and Sing (1970), SOD ...
Growth rates in vegetative and reproductive tissue of Parmelia cumberlandia after relocation to a... more Growth rates in vegetative and reproductive tissue of Parmelia cumberlandia after relocation to a new environment. Canadian Field-Naturalist 91(2): 134-140. Abstract. A large colony of the lichen Parmelia cumberlandia (Gyeln.) Hale and its rock substrate were subdivided by means of a diamond saw and the portions relocated at different sites. After 1 year, vegetative growth and trends in the production of apothecial tissue were observed. The annual growth rates recorded for the vegetative part of the thallus of P. cumberlandia were considerably higher than for any other species of Parmelia reported previously and are among the highest reported for any lichen. In sections of the thallus transported to new and slightly more southerly locations, previously existing apothecia expanded to a greater extent, and new apothecia developed more frequently, than in the control location.
Archives of Environmental Contamination and Toxicology, Aug 1, 2003
The influence of copper was assessed on wild and tolerant strains of the lichen photobiont Trebou... more The influence of copper was assessed on wild and tolerant strains of the lichen photobiont Trebouxia erici and shown to have multiple toxic effects. Addition of 4 mM copper chloride into Trebouxia media reduced growth rates of the wild type to less than 1% of control levels. It also injured cell membranes, inhibited dehydrogenase activity, altered pigment composition, and reduced activity of photosystem II. Membrane damage was assessed through measuring electrical conductivity and potassium content, dehydrogenase activity by degree of conversion of 2,3,5-triphenyl tetrazolium chloride to red triphenylformazan, and functioning of PS II by chlorophyll a fluorescence. In respect to most parameters the tolerant strain was usually less affected by copper than the wild strain and, in some cases, not at all. We demonstrated by inductively coupled plasma atomic emission spectrometry and energy-dispersive X-ray microanalysis that enriched copper in the medium resulted in increased uptake by both wild and tolerant photobiont cells, but extracellular concentrations were significantly higher in the tolerant strain. This suggested that, at least in vitro, extracellular deposition was a mechanism of copper tolerance.
Free proline accumulation has been observed in response to heavy metal stress in plants including... more Free proline accumulation has been observed in response to heavy metal stress in plants including algae, however nothing is known about its role in copper sensitivity or copper tolerance in lichen photobionts. Copper uptake, potassium efflux and free proline accumulation were determined in copper-enriched liquid cultures of wild-type Trebouxia erici as well as in copper-tolerant strain. By using inductively coupled plasma atomic emission spectrometry we found that the highest intracellular copper uptake from 2 mM copper media occurred within 4 h in both strains, but significantly less was accumulated by the tolerant strain. The copper-tolerant strain exhibited significantly more intracellular proline and significantly less potassium efflux than the wild strain. By 24 h differences between strains in intracellular copper diminished, as concentrations in both strains reached their highest levels. At the same time proline accumulations decreased significantly. Growth, pigment content, chlorophyll a degradation and chlorophyll a fluorescence were decreased by high copper concentration in the agar media after 2 weeks of cultivation, more pronounced in wild-type of T. erici. Adding proline alleviated the toxic effects of copper in both strains, but markedly so in the case of the tolerant strain.
A significant negative correlation was found between the quantity of acetone-extractable phenolic... more A significant negative correlation was found between the quantity of acetone-extractable phenolic compounds and the degree of enzyme polymorphism in eight eastern North American populations of Umbilicaria americana. In sites at higher elevations, where UV irradiance was more intense, phenolic levels were significantly lower and within-stand enzyme variability significantly greater than in low elevation sites. Similarly, the phenolic content of thalli collected in Ontario, Canada, over a 16-month sampling period was negatively correlated with mean monthly UV-B irradiance.
Old-growth forests are declining throughout eastern North America, especially toward the northern... more Old-growth forests are declining throughout eastern North America, especially toward the northern limit of the deciduous formation where gently undulating topography and milder climate especially encourage human activity. Remnants exist, but do they retain the defining characteristics of the original vegetation? The objective was to marshal information required to answer this question, and toward this objective we assessed vegetation in a small 1 ha remnant of maple-beech forest with no history of past logging and compared it to well known and larger old-growth areas in the region. We used Curtiss (1959) Point Quarter method to provide full quantitative data for trees, saplings, shrub and herbs. Size class distribution of trees and successional status of the stand were assessed. As a general conclusion, we found that tree species richness of our remnant was higher than most recognized large old-growth forests and, while the herbaceous understorey was poorer in species than larger tracts, it exhibited three provincially rare species. Furthermore, the successional status and structural complexity of the remnant were typical of old-growth forests. In overall comparative terms, the remnant was found not be an outlier when ordinated with larger forests. It thus is safe to conclude that this remnant constitutes an ecological benchmark well worth protection, despite its limited size. Abbreviations: asl-above sea level; BABH-basal area 1 m above ground; DBH-diameter 1 m above ground; DCA-detrended correspondence analysis; DF-density-frequency index or sum of relative frequency and relative density; DFD-sum of relative density; relative frequency and relative dominance also called importance value;
Ultraviolet light is known to alter thallus concentrations of lichen phenolics, thus attempts wer... more Ultraviolet light is known to alter thallus concentrations of lichen phenolics, thus attempts were made to assess photostability. Lichen products extracted from 14 lichen species were applied to thin-layer chromatography (TLC) plates, exposed to high intensity UV-A/B and developed in suitable solvents. Banding patterns of extracts containing gyrophoric acid, lecanoric acid and tenuiorin were not altered by UV, but patterns of species containing usnic acid, atranorin, barbatic acid and didymic acid changed visibly. Thin-layer chromatography, gas chromatography and mass spectroscopy showed that usnic acid is broken down by UV into photoproducts with molecular weights lower than usnic acid itself. However, banding patterns of extracts from intact thalli exposed to UV were not visibly different from unexposed controls for any of the four species tested, Cladonia uncialis, Cladonia rangiferina, Peltigera aphthosa and Umbilicaria mammulata. Nevertheless, quantitative analysis of Cladonia uncialis showed consistently lower-than-control amounts of usnic acid in irradiated subsamples of all whole thalli tested, suggesting that degradation probably occurred. Live air-dried material consistently maintained control levels of phenolics after irradiation, but hydrated subsamples tended to show decreased concentrations of usnic acid.
Cellulose-acetate filter disks were found convenient for the cultivation of lichen mycobionts and... more Cellulose-acetate filter disks were found convenient for the cultivation of lichen mycobionts and artificial re-synthesis of lichens, and using this method of culture we tested the effects of acidification on Cladonia cristatella Tuck. Mycobionts subjected to short-term strongly acidic conditions showed decreased formazan production compared to colonies grown at optimal pH 5.0. Disk-supported synthetic lichens grown at pH 3.0 or 5.0 exhibited no significant differences in pigment chemistry or photosynthetic efficiency compared to those at pH 7.0, but all of these parameters changed at pH 1.5. Chlorophyll a integrity significantly decreased under all treatments involving acidified water, with the highest amount of degradation at pH 1.5. At pH 1.5, significantly decreased concentrations of both -carotene and total carotenoids were observed. A significant decrease in chlorophyll a fluorescence was also shown at pH 1.5.
Transplantation to new locations is used widely to propagate horticultural and agricultural speci... more Transplantation to new locations is used widely to propagate horticultural and agricultural species but is also promoted as a means of relocating whole communities that stand in the way of development. It may be used as well to move vegetation from the field for experimentation under controlled conditions. Transplantation has not in the past been considered a reliable means of conserving threatened species or reproducing functional characteristics of natural communities, and has been regarded by many as highly ineffective. However, its potential must now be reexamined because of the many recent transplant attempts as well as advances in related fields. Recent trials illustrate that individual endangered species are still particularly difficult to transplant and displaced multi-species sods are almost always changed in the process. Exact reconstruction of communities from individual components is next to impossible because the full complement of species, including critical microbial components, is almost never known. Owing to a limited understanding of phenology, reproduction, functional roles, and interrelationships among constituent microbes, cryptogams, vascular plants, and fauna, transplants may be placed into sites with both biological and physical insufficiencies. Genetic diversity may be lost or, if genotypes from diverse sources are mixed, outbreeding depression may result. Recent advances in soil science, microbial ecology, and population genetics have in some cases improved the effectiveness of transplantation, but new insights mainly permit a fuller appreciation of the causes of failure. Home-site advantage has been demonstrated, and habitat protection appears to be the best and perhaps only reliable way of preserving intact natural communities and rare species. Furthermore, experimentation with vegetational mats under controlled conditions may have little relevance to natural ecosystems.
Energy-dispersive X-ray microanalysis and X-ray mapping were used to study metal uptake by the li... more Energy-dispersive X-ray microanalysis and X-ray mapping were used to study metal uptake by the lichens Lecidea lithophila and Rhizocarpon oederi growing on centuries old copper mine spoil heaps in Špania Dolina, Slovakia. Mineral waste derived from historical extraction of copper was still rich in the heavy metals iron and aluminum, while copper was not detectable. In apothecia of both species there was, as expected, significantly more C than in the substrate but the same levels of O, Na and Mg. The elements Al, Si, and K were present in apothecia of both lichen species, but in significantly lower concentrations than in the substrate. The weight percent of Fe for L. lithophila ascocarps was also significantly lower than the substrate, but Cu concentrations were higher. Elemental composition of the vegetative part of thalli, determined only in L. lithophila, did not differ significantly from that of the substrate.
A significant negative correlation was found between the quantity of acetone-extractable phenolic... more A significant negative correlation was found between the quantity of acetone-extractable phenolic compounds and the degree of enzyme polymorphism in eight eastern North American populations of Umbilicaria americana. In sites higher elevations, where UV irradiance was more intense, phenolic levels were significantly lower and within-stand enzyme variability significantly greater than in low elevation sites. Similarly, the phenolic content of thalli collected in Ontario, Canada, over a 16-month sampling period was negatively correlated with mean monthly UV-B irradiance.
The foliose lichen Umbilicaria americana Poelt & Nash was exposed to spectrally altered r... more The foliose lichen Umbilicaria americana Poelt & Nash was exposed to spectrally altered radiation in three growth chamber experiments and one field experiment. After 1 week in growth chambers the phenolic content (% w/w) increased significantly under a spectral band including visible light and UV-A, and the increase was greater when intensity was higher. Under exposure to both UV-A and UV-B the concentration of phenolics was lower than with UV-A alone and, depending on dosage, approached or achieved control levels. In a population of U. americana on a vertical rock face, the interaction between filter treatments and collection dates had a highly significant effect on phenolic levels (P = 0.01). In thalli protected from UV-B, phenolic levels were higher than in those exposed to natural sunlight in June and October, but the same response was not observed in July and August. Thallus groupings covered by filters that admitted both UV-B and UV-A accumulated less phenolics than controls in August, but on other sampling dates contained the same concentrations. Key words: Umbilicaria americana, UV-A, UV-B, depsides, tridepsides.
... Abstract. Cellulose-acetate disks were found convenient for the cultivation of lichen myco-bi... more ... Abstract. Cellulose-acetate disks were found convenient for the cultivation of lichen myco-bionts and artificial resynthesis and culture of the lichen Cladonia cristatella. ... Page 3. 2003] BACKOR & FAHSELT: LICHEN CULTURE SUBSTRATE 441 160 - 140 a E 120 ' 100 ...
... and one of P. rigida Lynge were sampled. ... Although earlier numerical taxonomists favored t... more ... and one of P. rigida Lynge were sampled. ... Although earlier numerical taxonomists favored the use of large numbers of characters, it has more recently been shown (Wishart, 1969; Orloci, 1973, 1976) that characters contributing mini-mally to the classification are harmful rather ...
... 1982; Fahselt et al. 1995; Jeran et al. 1995). ... Air-dried li-chens that are rewetted exper... more ... 1982; Fahselt et al. 1995; Jeran et al. 1995). ... Air-dried li-chens that are rewetted experience a period of accelerated respiration, but after approximately 10 hr, normal levels of respiration are resumed (Smith & Molesworth 1973). ...
Thalli from a population of Cladonia cristatella Tuck. were sorted according to mor- phological c... more Thalli from a population of Cladonia cristatella Tuck. were sorted according to mor- phological characters and the ten most common types were determined on the basis of podetial biomass. From a large podetial sample of each morphotype which was available in sufficient quan- tity, crude protein extracts were prepared and subjected to isoelectricfocusing. Comparisons were made among common morphological variants on the basis of gels stained for the activity of 12 enzymes. A few of the common morphotypes were sampled more intensively in order to provide an indication of possible enzyme polymorphism within morphological forms. There was little evidence of variation in dehydrogenase enzymes among morphotypes but there were differences with respect to esterase and acid and alkaline phosphatases. However, variation in enzyme forms was also observed within morphotypes. There was, thus, no indication of unusual differences among mor- phological variants of C. cristatella and also no evidence to suggest that distinct morphological forms are diverging from one another in the population.
... Türk, Elfie Stocker-Wörgötter. (2008) Production and Bioactivity of Common Lichen Metabolites... more ... Türk, Elfie Stocker-Wörgötter. (2008) Production and Bioactivity of Common Lichen Metabolites as Exemplified by Heterodea muelleri (Hampe) Nyl.. Journal of Chemical Ecology 34:2, 113-120 Online publication date: 1-Feb-2008. N. Valencia-Islas, A. Zambrano, JL Rojas. ...
The foliose lichen Parmelia aurulenta Tuck. (Parmeliaceae) was examined using scanning electron m... more The foliose lichen Parmelia aurulenta Tuck. (Parmeliaceae) was examined using scanning electron microscopy and transmittance electron microscopy. The algal component was identified as Trebouxia and the physical relationship between algal cells and fungal hyphae was studied. An impression of the three-dimensional relationship between the two symbionts was obtained with the scanning electron microscope, and the sites of extensive crystal deposition were identified.
... CECILIA HAGEMAN AND DIANNE FAHSELT Department of Plant Sciences, University of Western Ontari... more ... CECILIA HAGEMAN AND DIANNE FAHSELT Department of Plant Sciences, University of Western Ontario, London, Ontario N6A 5B7, Canada ... Staining recipes for IDH, 6PG and GDH were from Adams and Joly (1980), G6P, EST and ALP from Brewer and Sing (1970), SOD ...
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