Titre :	Population based approaches in the study of Pilosella Hill (Asteraceae) : a new view of its taxonomy ?
Type de document :	Livre
Auteurs :	Frantisek Krahulec, Auteur ; Anna Krahulcová, Auteur
Importance :	pp. 15-25
Langues :	Anglais
Résumé :	"We present a structure of the Pilosella populations occurring in the Krkonose Mts, northern Czech Republic. Each basic species, hybridogenous species and recent hybrid is documented by its frequency, cytotypes, breeding system, and chloroplast haplotypes. We compare this structure with the situation in another mountain range, the Sumava Mts in the south western Czech Republic. Both regions have the same structure ofhybridising species, but the resulting population are different. We de duce that random phenomena in the past and the residual sexuality of apomictic species has influenced the present population composition. Our results are discussed in connection with existing approaches to the taxonomy of Pilosella." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Krahulec F., Krahulcová A., 2006 - Population based approaches in the study of Pilosella Hill (Asteraceae) : a new view of its taxonomy ? In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 15-25.
ID PMB :	6461
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6461

Population based approaches in the study of Pilosella Hill (Asteraceae) : a new view of its taxonomy ? [Livre] / Frantisek Krahulec, Auteur ; Anna Krahulcová, Auteur . - [s.d.] . - pp. 15-25.
Langues : Anglais

Résumé :	"We present a structure of the Pilosella populations occurring in the Krkonose Mts, northern Czech Republic. Each basic species, hybridogenous species and recent hybrid is documented by its frequency, cytotypes, breeding system, and chloroplast haplotypes. We compare this structure with the situation in another mountain range, the Sumava Mts in the south western Czech Republic. Both regions have the same structure ofhybridising species, but the resulting population are different. We de duce that random phenomena in the past and the residual sexuality of apomictic species has influenced the present population composition. Our results are discussed in connection with existing approaches to the taxonomy of Pilosella." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Krahulec F., Krahulcová A., 2006 - Population based approaches in the study of Pilosella Hill (Asteraceae) : a new view of its taxonomy ? In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 15-25.
ID PMB :	6461
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6461

Titre :	New field botanists for the future
Type de document :	Livre
Auteurs :	Franklyn Hugh Perring, Auteur
Importance :	pp. 153-154
Langues :	Anglais
Résumé :	"Clive Stace was a precocious field botanist who contributed to the first Maps Scheme as a teen-aged boy in the mid-1950s, significantly encouraged by his biology master and the local natural history society in Tunbridge Wells and by the nearby Francis Rose. And he was not al one - other youngsters, notably Raymond Harley at Harrow and David Allen at Rugby, were similarly encouraged to high quality work. But where are such young people today? Today very few biology teachers have the taxonomic skills, or the realisation of the need for field botanists, for them to be able or willing to promote it as a hobby, let alone as a career. Yet it is clear that there never was a time when there was so much demand for trained field botanists and never a time when there were so few available. To meet this gap the BSBI is working with many others to produce materials, literature and courses to make opportunities for careers in field otany widely known." (source : auteur)
Type de publication :	article de livre
Référence biblio :	Perring F., 2006 - New field botanists for the future. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 153-154.
ID PMB :	6451
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6451

New field botanists for the future [Livre] / Franklyn Hugh Perring, Auteur . - [s.d.] . - pp. 153-154.
Langues : Anglais

Résumé :	"Clive Stace was a precocious field botanist who contributed to the first Maps Scheme as a teen-aged boy in the mid-1950s, significantly encouraged by his biology master and the local natural history society in Tunbridge Wells and by the nearby Francis Rose. And he was not al one - other youngsters, notably Raymond Harley at Harrow and David Allen at Rugby, were similarly encouraged to high quality work. But where are such young people today? Today very few biology teachers have the taxonomic skills, or the realisation of the need for field botanists, for them to be able or willing to promote it as a hobby, let alone as a career. Yet it is clear that there never was a time when there was so much demand for trained field botanists and never a time when there were so few available. To meet this gap the BSBI is working with many others to produce materials, literature and courses to make opportunities for careers in field otany widely known." (source : auteur)
Type de publication :	article de livre
Référence biblio :	Perring F., 2006 - New field botanists for the future. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 153-154.
ID PMB :	6451
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6451

Titre :	Endemic vascular plants in the Nordic flora
Type de document :	Livre
Auteurs :	Bengt Jonsell, Auteur ; Thomas Karlsson, Auteur
Importance :	pp. 123-133
Langues :	Anglais
Mots-clés :	endémisme  glaciation
Résumé :	"The endemic taxa of vascular plants of the Nordic countries amount to about 130, of which 46 are currently regarded as species (Hieracium, Taraxacum, and the Ranunculus auricomus complex exc1uded). A postglacial origin, i.e. a time span of maximally 10,000 years of evolution, is now postulated for ail Nordic endemics. There are five allopolyploid sexual endemic species; Arabidopsis suecica, Corydalis gotlandica, Draha cacuminum, Prim uZa scandinavica and Saxifraga osloënsis. Outside the large apomictic groups mentioned above, only about 40 apomictic endemics are recognized. A large proportion of the non-hybrid and non-apomictic endemics have probably originated from ecotypes. Many Nordic endemics are members of intricate species complexes with subtle and often disputed taxonomie Iimits. The Nordic endemics are geographically concentrated, but far from exc1usively, to a number of 'hot' areas with particular ecological and historical conditions, the most important of which are the Scandes, the Baltic land-lift shores and the Baltic Iimestone islands of Gland and Gotland. A smaller number of endemic taxa are found at the coasts of NW Jylland (Denmark), along the Arctic Ocean coast, and in Iceland. The isolated Nordic islands and the island groups to the north and west (Spitzbergen, Jan Mayen, and the Faroes) have few or no endemic taxa." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Jonsell B., Karlsson T., 2006 - Endemic vascular plants in the Nordic flora. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 123-133.
ID PMB :	6453
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6453

Endemic vascular plants in the Nordic flora [Livre] / Bengt Jonsell, Auteur ; Thomas Karlsson, Auteur . - [s.d.] . - pp. 123-133.
Langues : Anglais

Mots-clés :	endémisme  glaciation
Résumé :	"The endemic taxa of vascular plants of the Nordic countries amount to about 130, of which 46 are currently regarded as species (Hieracium, Taraxacum, and the Ranunculus auricomus complex exc1uded). A postglacial origin, i.e. a time span of maximally 10,000 years of evolution, is now postulated for ail Nordic endemics. There are five allopolyploid sexual endemic species; Arabidopsis suecica, Corydalis gotlandica, Draha cacuminum, Prim uZa scandinavica and Saxifraga osloënsis. Outside the large apomictic groups mentioned above, only about 40 apomictic endemics are recognized. A large proportion of the non-hybrid and non-apomictic endemics have probably originated from ecotypes. Many Nordic endemics are members of intricate species complexes with subtle and often disputed taxonomie Iimits. The Nordic endemics are geographically concentrated, but far from exc1usively, to a number of 'hot' areas with particular ecological and historical conditions, the most important of which are the Scandes, the Baltic land-lift shores and the Baltic Iimestone islands of Gland and Gotland. A smaller number of endemic taxa are found at the coasts of NW Jylland (Denmark), along the Arctic Ocean coast, and in Iceland. The isolated Nordic islands and the island groups to the north and west (Spitzbergen, Jan Mayen, and the Faroes) have few or no endemic taxa." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Jonsell B., Karlsson T., 2006 - Endemic vascular plants in the Nordic flora. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 123-133.
ID PMB :	6453
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6453

Titre :	Evolution in thyme enough ? Rapid physiological evolution in response to pollution in two common British plants
Type de document :	Livre
Auteurs :	John Richards, Auteur ; Helena Winsnes, Auteur ; Lynn Whitfield, Auteur
Importance :	pp. 135-148
Langues :	Anglais
Mots-clés :	tolérance
Résumé :	"Speciation is often confused with evolution, but taxonomic recognition of a species depends on morphological distinctiveness. We argue that when plants are challenged by rapid and drastic environmental changes such as those resulting from pollution, climate change, or new predators and pathogens, they commonly show dramatic and often sympatric physiological evolution, but because this is normally cryptic ('silent') it is not recognised by taxonomists and so tends to be ignored by conservationists and policy makers. The principle is illustrated by wild thyme Thymus polytrichus from metal-rich calaminarian grasslands, and perennial rye-grass Lolium perenne from salted road-verges, both of which appear to have evolved tolerance within the last 100 years. Zinc tolerance in T. polytrichus is biparentally dominant. We were unable to detect a metabolic co st to this tolerance, or for salt tolerance found in roadside L. perenne from several sites. We were unable to induce tolerance by early exposure to salt, and strains that appeared to be innate1y tolerant were not later affected by this early exposure. In contrast, susceptible strains showed a 'hang-over' effect from early exposure, even when grown in salt-free conditions." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Richards J., Winsnes H., Whitfield L., 2006 - Evolution in thyme enough ? Rapid physiological evolution in response to pollution in two common British plants. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 135-148.
ID PMB :	6454
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6454

Evolution in thyme enough ? Rapid physiological evolution in response to pollution in two common British plants [Livre] / John Richards, Auteur ; Helena Winsnes, Auteur ; Lynn Whitfield, Auteur . - [s.d.] . - pp. 135-148.
Langues : Anglais

Mots-clés :	tolérance
Résumé :	"Speciation is often confused with evolution, but taxonomic recognition of a species depends on morphological distinctiveness. We argue that when plants are challenged by rapid and drastic environmental changes such as those resulting from pollution, climate change, or new predators and pathogens, they commonly show dramatic and often sympatric physiological evolution, but because this is normally cryptic ('silent') it is not recognised by taxonomists and so tends to be ignored by conservationists and policy makers. The principle is illustrated by wild thyme Thymus polytrichus from metal-rich calaminarian grasslands, and perennial rye-grass Lolium perenne from salted road-verges, both of which appear to have evolved tolerance within the last 100 years. Zinc tolerance in T. polytrichus is biparentally dominant. We were unable to detect a metabolic co st to this tolerance, or for salt tolerance found in roadside L. perenne from several sites. We were unable to induce tolerance by early exposure to salt, and strains that appeared to be innate1y tolerant were not later affected by this early exposure. In contrast, susceptible strains showed a 'hang-over' effect from early exposure, even when grown in salt-free conditions." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Richards J., Winsnes H., Whitfield L., 2006 - Evolution in thyme enough ? Rapid physiological evolution in response to pollution in two common British plants. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 135-148.
ID PMB :	6454
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6454

Titre :	Factors affecting hybridisation from GM oilseed rape in the United Kingdom
Type de document :	Livre
Auteurs :	Mike J. Wilkinson, Auteur ; Joel Allainguillaume, Auteur
Importance :	pp. 111-122
Langues :	Anglais
Mots-clés :	hybridation  OGM
Résumé :	"On a global scale, the cultivation of genetically modified (GM) crops has risen dramatically over the past five years and now stands at almost 60Mha. Whilst there has been no commercial release of GM crops in the UK to date, the government is currently reviewing the situation and releases are possible within a relative1y short time frame. Concerns over the possible consequences of widespread use of GM crops centre on the possible risks to human health and to the environment. The latter range from indirect effects such as those caused by changed farm practice or agricultural market forces through to direct impacts of a transgene either on the crop itse1f outside cultivation or on weedy or wild relatives following gene flow. In this talk, 1 shaH use the possibility ofunwanted environmental change arising from gene flow between GM oilseed rape and natural populations of Brassica rapa to illustrate the complexity of assessing risks on a National scale" (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Wilkinson M., Allainguillaume J., 2006 - Factors affecting hybridisation from GM oilseed rape in the United Kingdom. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 111-122.
ID PMB :	6455
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6455

Factors affecting hybridisation from GM oilseed rape in the United Kingdom [Livre] / Mike J. Wilkinson, Auteur ; Joel Allainguillaume, Auteur . - [s.d.] . - pp. 111-122.
Langues : Anglais

Mots-clés :	hybridation  OGM
Résumé :	"On a global scale, the cultivation of genetically modified (GM) crops has risen dramatically over the past five years and now stands at almost 60Mha. Whilst there has been no commercial release of GM crops in the UK to date, the government is currently reviewing the situation and releases are possible within a relative1y short time frame. Concerns over the possible consequences of widespread use of GM crops centre on the possible risks to human health and to the environment. The latter range from indirect effects such as those caused by changed farm practice or agricultural market forces through to direct impacts of a transgene either on the crop itse1f outside cultivation or on weedy or wild relatives following gene flow. In this talk, 1 shaH use the possibility ofunwanted environmental change arising from gene flow between GM oilseed rape and natural populations of Brassica rapa to illustrate the complexity of assessing risks on a National scale" (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Wilkinson M., Allainguillaume J., 2006 - Factors affecting hybridisation from GM oilseed rape in the United Kingdom. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 111-122.
ID PMB :	6455
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6455

Titre :	How many orchid species are currently native to the British Isles ?
Type de document :	Livre
Auteurs :	Richard M. Bateman, Auteur
Importance :	pp. 89-110
Langues :	Anglais
Mots-clés :	classification  DNA  phylogénétique  population génétique
Résumé :	"The British Isles probably host the most intensively studied flora in the world, and within that flora the Orchidaceae has long been the most intensively studied family. Nonetheless, molecular phylogenetic studies performed only during the last decade have revolutionised our understanding of species relationships among European orchids, eliminating former monotypic genera such as Aceras, Coe/oglossum and Hammarbya, apportioning many former Orchis species to expanded concepts of Anacamptis and Neotinea, and combining 'Listera' into Neottia. Emphasis has now switched from species comparison to species delimitation, integrating morphometric approaches with population genetic techniques via simultaneous ordinations. Early results suggest that several distinct speciation mechanisms operate within the British and Irish orchid flora, and challenge the validity of several 'Schedule 8' species. No meaningful differences exist between British Dactylorhiza 'lapponica' and D. 'traunsteineri' , and neither represents the same allopolyploid speciation event as D. traunsteineri from the type locality in Austria. AIso, contrary to the recent Atlas of the British & Irish flora, D. majalis s.s. does not occur in the British Isles. By contrast, three habitat 'races' within Gymnadenia merit species status. Epipactis 'youngiana' is not reliably distinct from E. helleborine, whereas the autogamous E. leptochila and E. dunensis both warrant species status, alongside E. sancta recently described from Lindisfame. Controversial taxa are either widely recognised but lack biological cohesion (Emperor's New Clothes species), rarely if ever recognised but possess biological cohesion (Cinderella species, including Robinson Crusoe species recently diverged on islands such as Dactylorhiza ebudensis), or are migrating northward, presumably in response to climate change (Bleriot species, such as Serapias parviflora). Recent arrivaIs by origination or migration are partly negated by extirpation of longer established species, notably Spiranthes aestivalis and arguably Epipogium aphyllum. Present evidence suggests that the orchid flora of the British Isles (excluding the iogeographically French Channel Islands) currently consists of52 species in 20 genera; these taxa are herein reclassified in anticipation of the third edition of Stace's Flora." (source : auteur)
Type de publication :	article de livre
Référence biblio :	Bateman R., 2006 - How many orchid species are currently native to the British Isles ? In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 89-110.
ID PMB :	6456
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6456

How many orchid species are currently native to the British Isles ? [Livre] / Richard M. Bateman, Auteur . - [s.d.] . - pp. 89-110.
Langues : Anglais

Mots-clés :	classification  DNA  phylogénétique  population génétique
Résumé :	"The British Isles probably host the most intensively studied flora in the world, and within that flora the Orchidaceae has long been the most intensively studied family. Nonetheless, molecular phylogenetic studies performed only during the last decade have revolutionised our understanding of species relationships among European orchids, eliminating former monotypic genera such as Aceras, Coe/oglossum and Hammarbya, apportioning many former Orchis species to expanded concepts of Anacamptis and Neotinea, and combining 'Listera' into Neottia. Emphasis has now switched from species comparison to species delimitation, integrating morphometric approaches with population genetic techniques via simultaneous ordinations. Early results suggest that several distinct speciation mechanisms operate within the British and Irish orchid flora, and challenge the validity of several 'Schedule 8' species. No meaningful differences exist between British Dactylorhiza 'lapponica' and D. 'traunsteineri' , and neither represents the same allopolyploid speciation event as D. traunsteineri from the type locality in Austria. AIso, contrary to the recent Atlas of the British & Irish flora, D. majalis s.s. does not occur in the British Isles. By contrast, three habitat 'races' within Gymnadenia merit species status. Epipactis 'youngiana' is not reliably distinct from E. helleborine, whereas the autogamous E. leptochila and E. dunensis both warrant species status, alongside E. sancta recently described from Lindisfame. Controversial taxa are either widely recognised but lack biological cohesion (Emperor's New Clothes species), rarely if ever recognised but possess biological cohesion (Cinderella species, including Robinson Crusoe species recently diverged on islands such as Dactylorhiza ebudensis), or are migrating northward, presumably in response to climate change (Bleriot species, such as Serapias parviflora). Recent arrivaIs by origination or migration are partly negated by extirpation of longer established species, notably Spiranthes aestivalis and arguably Epipogium aphyllum. Present evidence suggests that the orchid flora of the British Isles (excluding the iogeographically French Channel Islands) currently consists of52 species in 20 genera; these taxa are herein reclassified in anticipation of the third edition of Stace's Flora." (source : auteur)
Type de publication :	article de livre
Référence biblio :	Bateman R., 2006 - How many orchid species are currently native to the British Isles ? In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 89-110.
ID PMB :	6456
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6456

Titre :	What use is sex ? Rock sea-lavenders (Limonium binervosum agg.) revisited
Type de document :	Livre
Auteurs :	Martin Ingrouille, Auteur
Importance :	pp. 71-88
Langues :	Anglais
Mots-clés :	variation génétique  évolution
Résumé :	"Analysis of morphometric variation within and between populations of Limonium binervosum agg., rock sea-Iavender has revealed extensive, statistically significant, differentiation between populations of the same infra-specific taxon, even those growing in close geographical vicinity. Morphological groups are largely supported by patterns of amplified DNA fragment length polymorphisms but genetical distances contrast markedly from phenetic/morphological distances. It is recommended that a more informai and simplified classification of the group is utilised. The evolution of the obligately asexual group is discussed and it is suggested that much of the observed pattern of variation may be due to heritable epigenetic differences." (source : auteur)
Type de publication :	article de livre
Référence biblio :	Ingrouille M., 2006 - What use is sex ? Rock sea-lavenders (Limonium binervosum agg.) revisited. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 71-88.
ID PMB :	6457
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6457

What use is sex ? Rock sea-lavenders (Limonium binervosum agg.) revisited [Livre] / Martin Ingrouille, Auteur . - [s.d.] . - pp. 71-88.
Langues : Anglais

Mots-clés :	variation génétique  évolution
Résumé :	"Analysis of morphometric variation within and between populations of Limonium binervosum agg., rock sea-Iavender has revealed extensive, statistically significant, differentiation between populations of the same infra-specific taxon, even those growing in close geographical vicinity. Morphological groups are largely supported by patterns of amplified DNA fragment length polymorphisms but genetical distances contrast markedly from phenetic/morphological distances. It is recommended that a more informai and simplified classification of the group is utilised. The evolution of the obligately asexual group is discussed and it is suggested that much of the observed pattern of variation may be due to heritable epigenetic differences." (source : auteur)
Type de publication :	article de livre
Référence biblio :	Ingrouille M., 2006 - What use is sex ? Rock sea-lavenders (Limonium binervosum agg.) revisited. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 71-88.
ID PMB :	6457
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6457

Titre :	Molecular evolutionary rates shed new light on the relationships of Festuca, Lolium, Vulpia and related grasses (Loliinae, Pooideae, Poaceae)
Type de document :	Livre
Auteurs :	Pilar Catalán, Auteur ; Pedro Torrecilla, Auteur ; Jose Angel López Rodríguez, Auteur
Importance :	pp. 45-70
Langues :	Anglais
Mots-clés :	ITS  trn L.-F.  phylogénie
Résumé :	"Festuca L., Vulpia Gmel. and Latium L. are the three main genera of subtribe Loliinae, a group of temperate grasses characterized by their festucoid-type spikelet. Recent phylogenetic studies based on separate and combined analyses of nuclear ITS and chloroplast trnL-F nucleotide sequences have shown that the large genus Festuca, as traditionally circumscribed, is a paraphyletic assemblage of several Loliinae representatives. Monophyletic Festuca s.l. splits into two main diverging lineages, the 'broad-leaved Festuca' and the 'fine-leaved Festuca', each encompassing different genera and with several morphologically-intermediate taxa placed between them or at the base ofthe 'fine-Ieaved' clade. AH these lineages include both perennial and annual taxa that show significant and paraHel differences in rates of nucleotide substitution for the two genomes analyzed. Comparative rate analysis indicate that the 'fine-Ieaved Festuca' evolve, in general terms, faster than the 'broad-Ieaved Festuca', and have presumably been derived from them. Relative rate ratios support the minimum-generation-time hypothesis in both lineages, implying the existence of stabilized selection processes for the slow evolving perennials and rapid adaptive mechanisms for the rapidly evolving annuals. High divergences in rate heterogeneity may be responsible for unsatisfactory resolution at the basal node of the festucoid ITS tree. These results, together with conflicts between the ITS and the trnL-F trees in the placement of several taxa suggests that the existence of past reticulation events, might have profound implications on their classification." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Catalán P., Torrecilla P., López Rodríguez J., 2006 - Molecular evolutionary rates shed new light on the relationships of Festuca, Lolium, Vulpia and related grasses (Loliinae, Pooideae, Poaceae). In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 45-70.
ID PMB :	6458
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6458

Molecular evolutionary rates shed new light on the relationships of Festuca, Lolium, Vulpia and related grasses (Loliinae, Pooideae, Poaceae) [Livre] / Pilar Catalán, Auteur ; Pedro Torrecilla, Auteur ; Jose Angel López Rodríguez, Auteur . - [s.d.] . - pp. 45-70.
Langues : Anglais

Mots-clés :	ITS  trn L.-F.  phylogénie
Résumé :	"Festuca L., Vulpia Gmel. and Latium L. are the three main genera of subtribe Loliinae, a group of temperate grasses characterized by their festucoid-type spikelet. Recent phylogenetic studies based on separate and combined analyses of nuclear ITS and chloroplast trnL-F nucleotide sequences have shown that the large genus Festuca, as traditionally circumscribed, is a paraphyletic assemblage of several Loliinae representatives. Monophyletic Festuca s.l. splits into two main diverging lineages, the 'broad-leaved Festuca' and the 'fine-leaved Festuca', each encompassing different genera and with several morphologically-intermediate taxa placed between them or at the base ofthe 'fine-Ieaved' clade. AH these lineages include both perennial and annual taxa that show significant and paraHel differences in rates of nucleotide substitution for the two genomes analyzed. Comparative rate analysis indicate that the 'fine-Ieaved Festuca' evolve, in general terms, faster than the 'broad-Ieaved Festuca', and have presumably been derived from them. Relative rate ratios support the minimum-generation-time hypothesis in both lineages, implying the existence of stabilized selection processes for the slow evolving perennials and rapid adaptive mechanisms for the rapidly evolving annuals. High divergences in rate heterogeneity may be responsible for unsatisfactory resolution at the basal node of the festucoid ITS tree. These results, together with conflicts between the ITS and the trnL-F trees in the placement of several taxa suggests that the existence of past reticulation events, might have profound implications on their classification." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Catalán P., Torrecilla P., López Rodríguez J., 2006 - Molecular evolutionary rates shed new light on the relationships of Festuca, Lolium, Vulpia and related grasses (Loliinae, Pooideae, Poaceae). In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 45-70.
ID PMB :	6458
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6458

Titre :	Taxonomic complexity, conservation and recurrent origins of self-pollination in Epipactis (Orchidaceae)
Type de document :	Livre
Auteurs :	P. M. Hollingsworth, Auteur ; J. Squirrell, Auteur ; M.L. Hollingsworth, Auteur ; A. J. Richards, Auteur ; Richard M. Bateman, Auteur
Importance :	pp. 27-44
Langues :	Anglais
Mots-clés :	cpSSRs  plante endémique  marqueur génétique  RFLPs
Résumé :	"The recent post-glacial colonisation of Britain has given little time for the evolution of endemic plant species. The few British endemic species that have been recognised tend to occur in taxonomically complex groups that possess mechanisms promoting rapid diversi-fication. Such taxonomie complexity leads to problems for plant conservation because a species has to be circumscribed and recognised before its distribution, status and threats can be established. One classic example of the challenges for conservation in taxonomie ally complex groups is the British endemic orchid Epipactis youngiana. This species is afforded full legal conservation protection but is one of a large number of taxonomically difficult species recently recognised in the genus; it is difficult to distinguish from the more common E. helleborine, and its species status has been questioned. We have used a combination of genetic markers (allozymes, chloroplast microsatellites and RFLPs) from a large sample set to establish the taxonomie and conservation status of E. youngiana and to place it in the wider context of patterns of breeding system variation and taxon differentiation in the genus. Our data provide evidence that recurrent breeding system transitions between cross-pollination and self-pollination are an important mechanism for diversification in the genus, and there are numerous genetically different taxa that are homozygous and uniform for different subsets of allelic diversity found in allogamous species. E. youngiana is the one major exception to this pattern. It has a floral morphology consistent with self-pollination, but has not achieved reproductive isolation from E. helleborine. The potential mechanisms underlying the recurrent evolution of self-pollination in Epipactis are discussed, as is the need for developing conservation strategies that reflect dynamic diversification in the genus, rather than the current heavily typological (is it distinct or not?) species-based approach." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Hollingsworth P.-M., Squirrell J., Hollingsworth M.-L., Richards A.-J., Bateman R., 2006 - Taxonomic complexity, conservation and recurrent origins of self-pollination in Epipactis (Orchidaceae). In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 27-44.
ID PMB :	6459
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6459

Taxonomic complexity, conservation and recurrent origins of self-pollination in Epipactis (Orchidaceae) [Livre] / P. M. Hollingsworth, Auteur ; J. Squirrell, Auteur ; M.L. Hollingsworth, Auteur ; A. J. Richards, Auteur ; Richard M. Bateman, Auteur . - [s.d.] . - pp. 27-44.
Langues : Anglais

Mots-clés :	cpSSRs  plante endémique  marqueur génétique  RFLPs
Résumé :	"The recent post-glacial colonisation of Britain has given little time for the evolution of endemic plant species. The few British endemic species that have been recognised tend to occur in taxonomically complex groups that possess mechanisms promoting rapid diversi-fication. Such taxonomie complexity leads to problems for plant conservation because a species has to be circumscribed and recognised before its distribution, status and threats can be established. One classic example of the challenges for conservation in taxonomie ally complex groups is the British endemic orchid Epipactis youngiana. This species is afforded full legal conservation protection but is one of a large number of taxonomically difficult species recently recognised in the genus; it is difficult to distinguish from the more common E. helleborine, and its species status has been questioned. We have used a combination of genetic markers (allozymes, chloroplast microsatellites and RFLPs) from a large sample set to establish the taxonomie and conservation status of E. youngiana and to place it in the wider context of patterns of breeding system variation and taxon differentiation in the genus. Our data provide evidence that recurrent breeding system transitions between cross-pollination and self-pollination are an important mechanism for diversification in the genus, and there are numerous genetically different taxa that are homozygous and uniform for different subsets of allelic diversity found in allogamous species. E. youngiana is the one major exception to this pattern. It has a floral morphology consistent with self-pollination, but has not achieved reproductive isolation from E. helleborine. The potential mechanisms underlying the recurrent evolution of self-pollination in Epipactis are discussed, as is the need for developing conservation strategies that reflect dynamic diversification in the genus, rather than the current heavily typological (is it distinct or not?) species-based approach." (source : auteurs)
Type de publication :	article de livre
Référence biblio :	Hollingsworth P.-M., Squirrell J., Hollingsworth M.-L., Richards A.-J., Bateman R., 2006 - Taxonomic complexity, conservation and recurrent origins of self-pollination in Epipactis (Orchidaceae). In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 27-44.
ID PMB :	6459
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6459

Titre :	Keys for the future
Type de document :	Livre
Auteurs :	Richard J. Pankhurst, Auteur
Importance :	pp. 5-13
Langues :	Anglais
Mots-clés :	clé de détermination  outils de détermination
Résumé :	"Diagnostic keys for the identification of plants have been in use for hundreds ofyears, but computerisedkeys have only been around for the past thirty. The internet provides a handy means to publish keys, but the really important innovation lies in programs for interactive multi-access identification. There are hundreds of these available, but computerised descriptions of taxa in the British flora are scarce. Data exists for particular groups, such as Carex and Taraxacum, but the CDROM being prepared by ETI is planned to inc1ude a key for the whole flora. Although the complete list of different characters will be long, the number of characters needed for descriptions of individual taxa will be manageable. Published Floras, admirable though they are, are intentionally concise and severely limited in the amount of information that they can contain. In a computerised flora, there is no reason to not inc1ude complete descriptions, not to mention drawings, pictures, and maps. This data will need to be organised in sorne kind of database. It is not c1ear whether we shall be using portable PCs with high capacity or with wideband communication to a central system." (source : auteur)
Type de publication :	article de livre
Référence biblio :	Pankhurst R., 2006 - Keys for the future. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 5-13.
ID PMB :	6460
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6460

Keys for the future [Livre] / Richard J. Pankhurst, Auteur . - [s.d.] . - pp. 5-13.
Langues : Anglais

Mots-clés :	clé de détermination  outils de détermination
Résumé :	"Diagnostic keys for the identification of plants have been in use for hundreds ofyears, but computerisedkeys have only been around for the past thirty. The internet provides a handy means to publish keys, but the really important innovation lies in programs for interactive multi-access identification. There are hundreds of these available, but computerised descriptions of taxa in the British flora are scarce. Data exists for particular groups, such as Carex and Taraxacum, but the CDROM being prepared by ETI is planned to inc1ude a key for the whole flora. Although the complete list of different characters will be long, the number of characters needed for descriptions of individual taxa will be manageable. Published Floras, admirable though they are, are intentionally concise and severely limited in the amount of information that they can contain. In a computerised flora, there is no reason to not inc1ude complete descriptions, not to mention drawings, pictures, and maps. This data will need to be organised in sorne kind of database. It is not c1ear whether we shall be using portable PCs with high capacity or with wideband communication to a central system." (source : auteur)
Type de publication :	article de livre
Référence biblio :	Pankhurst R., 2006 - Keys for the future. In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 5-13.
ID PMB :	6460
Permalink :	http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6460