Showing papers in "Plant Systematics and Evolution in 1998"
TL;DR: In this article, the parsimony jackknife analysis was used to identify 1400 groups on the basis of all the chloroplast generbcL positions, including major taxa such as green plants, land plants, flowering plants, monocots and eudicots.
Abstract: The ever-larger data matrices resulting from continuing improvements in DNA sequencing techniques require faster and more efficient methods of phylogenetic analysis. Here we explore a promising new method, parsimony jackknifing, by analyzing a matrix comprising 2538 sequences of the chloroplast generbcL. The sequences included cover a broad taxonomic range, from cyanobacteria to flowering plants. Several parsimony jackknife analyses were performed, both with and without branch-swapping and multiple random addition sequences: 1) including all positions; 2) including only first and second codon positions; 3) including only third positions; and 4) using only transversions. The best resolution was obtained using all positions. Removal of third positions or transitions led to massive loss of resolution, although using only transversions somewhat improved basal resolution. While branch-swapping improved both resolution and the support found for several groups, most of the groups could be recovered by faster simple analyses. Designed to eliminate groups poorly supported by the data, parsimony jackknifing recognizes 1400 groups on the basis of allrbcL positions. These include major taxa such as green plants, land plants, flowering plants, monocots and eudicots. We include appendices of supported angiosperm families, as well as larger groups.
214 citations
TL;DR: Using the AFLP technique highly informative DNA fingerprints were generated from 19 taxa of Solanum sect.Petota (potatoes) and threeTaxa ofSolanum Sect.Lycopersicum (tomatoes), and classifications based on the molecular markers were generally in agreement with current taxonomic opinions.
Abstract: Using the AFLP technique highly informative DNA fingerprints were generated from 19 taxa ofSolanum sect.Petota (potatoes) and three taxa ofSolanum sect.Lycopersicum (tomatoes). Both phenetic and cladistic analyses were conducted from the individual genotypic level to the species level. An AFLP fingerprint, using a combination of suitable AFLP primers, generated 12 to 71 scorable fragments per genotype which was sufficient for taxonomic interpretation. The classifications based on the molecular markers were generally in agreement with current taxonomic opinions. Unexpectedly,S. microdontum was associated with ser.Megistacroloba rather than with ser.Tuberosa, andS. demissum (ser.Demissa) and species of ser.Acaulia appeared closely affiliated. AFLP is an efficient and reliable technique to generate biosystematic data and therefore a promising tool for evolutionary studies.
169 citations
TL;DR: The phylogeny of suprageneric groups in Cyperaceae has been examined by cladistic analysis ofrbcL sequence data of 80 species in 40 genera and the results support the family as monophyletic and derived from a juncaceous grade.
Abstract: The phylogeny of suprageneric groups inCyperaceae has been examined by cladistic analysis ofrbcL sequence data of 80 species in 40 genera. The results support the family as monophyletic and derived from a juncaceous grade.Oxychloe (Juncaceae) has moderate support as the sister taxon toCyperaceae. Several monophyletic groups correspond to previously recognised tribes, and some similarities are noted between this analysis and previous cladistic analyses of primarily morphological data. Support is also given for the removal ofHellmuthia from tribeHypolytreae, the transfer ofIsolepis nodosa toFicinia, and the inclusion ofOxycaryum andKyllingiella in tribeCypereae. A polytomy comprisingCyperus, Juncellus, Kyllinga andPycreus indicates a broader circumscription ofCyperus. The greatest uncertainty lies with the generic and tribal status of theScirpeae.
148 citations
TL;DR: Sequences ofrbcL andndhF were analysed independently and in combination to resolve phylogenetic relationships inLabiatae s.
Abstract: Sequences ofrbcL andndhF were analysed independently and in combination to resolve phylogenetic relationships inLabiatae s. l. Monophyly ofLabiatae s. l was supported by all three analyses.Congea tomentosa (Symphoremataceae) is nested withinLabiatae s. l. in therbcL analysis, but emerges as the sister group ofLabiatae s. l. in thendhF and combined analyses. Four noteworthy clades ofLabiate s. l. also are supported by all analyses corresponding to subfamiliesNepetoideae, Lamioideae, Pogostemonoideae andScutellarioideae. Monophyly of subfamiliesChloanthoideae andViticoideae is not supported. A clade comprisingTeucrioideae plusAjuga is supported byndhF and the combined analysis.
143 citations
TL;DR: It is suggested that in order to minimise nomenclatural change and to name only well supported clades, Potentilla should be split into several genera, while other previously recognised genera such as Duchesnea, Horkelia, andIvesia are best included inPotentilla.
Abstract: The circumscription ofPotentilla has varied widely. To investigate the monophyly ofPotentilla and the phylogenetic relationships of associated genera we used nuclear ribosomal internal transcribed spacer (ITS) DNA sequences. Fourteen species ofPotentilla (sensuWolf 1908) were included, some of which represent proposed segregate genera (such asArgentina, Comarum, Drymocallis, Duchesnea, Pentaphylloides, andSibbaldiopsis), and 17 other genera ofRosoideae, usingPrunus as outgroup. Our most parsimonious tree strongly implies thatPotentilla is not monophyletic. Forcing the monophyly ofPotentilla yields distinctly longer trees. Several morphological features appear to have evolved several times independently, including the swollen receptacle (“strawberry”) and ternate leaves. In order to minimise nomenclatural change and to name only well supported clades,Potentilla should be split into several genera, while other previously recognised genera such asDuchesnea, Horkelia, andIvesia are best included inPotentilla. We suggest, however, that a phylogenetic nomenclature (sensude Queiroz & Gauthier 1994) might be a better solution.
119 citations
TL;DR: The investigation of molecular data neither supports the phylogeny of Andersson nor the classification of Robbrecht, but instead indicates totally new relationships ofIsertieae, Mussaendeae, andSabiceeae.
Abstract: The circumscription of the Isertieae has been under debate for a long time and recently a phylogeny based on morphological data has been presented (ANDERSSON 1996), contradicting the classification of ROBBRECHT (1988, 1993). Our investigation of molecular
84 citations
TL;DR: The 4C DNA amounts of 86 species from Allium subgg.Allium, Rhizirideum, Bromatorrhiza, Melanocrommyum, Caloscordum andAmerallium show a 8.35-fold difference, which shows that a significant loss and/or gain of DNA has occurred during evolution.
Abstract: The 4C DNA amounts of 86 species fromAllium subgg.Allium, Rhizirideum, Bromatorrhiza, Melanocrommyum, Caloscordum andAmerallium show a 8.35-fold difference ranging from 35.60 pg (A. ledebourianum, 2n = 16) to 297.13 pg (A. validum 2n = 56). At diploid level the difference is 3.57-fold betweenA. ledebourianum (35.60 pg) andA. ursinum (127.14 pg). This shows that a significant loss and/or gain of DNA has occurred during evolution. On average subgg.Rhizirideum andAllium have less DNA amount than subgg.Melanocrommyum andAmerallium. The distribution of nuclear DNA amounts does not show discontinuous pattern and regular groups. The evolution of genome size has been discussed in relation to polyploidy and genomes, heterochromatin, adaptive changes in morphological characteristics, phenology and ecological factors, and infrageneric classification.
78 citations
TL;DR: A phylogenetic analysis was conducted on sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA in 23 species of Aveneae and suggests unexpectedly close affinities of the agronomically important genusAvena to comparatively small-flowered taxa ofAveneae.
Abstract: A phylogenetic analysis was conducted on sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA in 23 species ofAveneae (Poaceae subfam.Pooideaae). These sequences ofHelictotrichon spp.,Arrhenatherum elatius, Avena spp.,Trisetum spp.,Koeleria spp.,Holcus lanatus, Alopecurus vaginatus together with published ITS sequences of furtherAveneae, Poeae, Triticeae, andBromeae were analysed by the neighbor-joining distance method to assess the molecular phylogenetic relationship in perennial and annualAveneae. The results suggest unexpectedly close affinities of the agronomically important genusAvena to comparatively small-flowered taxa ofAveneae. GenusArrhenatherum and small-flowered subgenera ofHelictotrichon are close extant relatives. The large genusHelictotrichon is para- if not polyphyletic, only its subgenera are monophyletic.Trisetum is clearly separated fromHelictotrichon and forms together withKoeleria and perhaps others a monophyletic lineage which is characterised by a conspicuous 9-bp deletion in ITS1. The impact of the ITS data on the delineation of some genera and subtribes ofAveneae and on the recognition of their biogeographical and ecological patterns is outlined.
69 citations
TL;DR: The hyperarid coastal Atacama and Peruvian Deserts along the Pacific coast of South America contain a surprisingly rich flora of bromeliad species, many of which grow at the absolute limits of vascular plant tolerance.
Abstract: Studies of geographic distribution and physiological adaptations in theBromeliaceae of coastal Chile and Peru provide insights into the ecological patterns of habit selection and speciation. The hyperarid coastal Atacama and Peruvian Deserts along the Pacific coast of South America contain a surprisingly rich flora of bromeliad species. These include representatives of all threeBromeliaceae subfamilies: two terrestrialBromelioideae and two terrestialPitcairnioideae, all with rooted growth morphologies, and 14 species ofTillandsioideae (allTillandsia) with epiphytic and unrooted, terrestraial representatives. TheBromelioideae are represented by two species ofPuya
Molina, one each in Peru and Chile. ThePitcairnioideae are represented by two genera,Deuterocohnia andPitcairnia, with one species each. The 14Tillandsia species are distributed in five subgenera which have successfully invaded the coastal deserts, and include both widespread and local endemics with xeromorphic adaptations. All theTillandsia species are epiphytic in the broad sense, but in addition to growing on plants, they are found growing on rocks (i.e. saxicolous or epilithic). Six species (T. purpurea, T. latifolia, T. capillaris, T. marconae, T. werdermanii, andT. landbeckii) have evolved a highly specialized substrate ecology where they grow essentially unrooted on sand (i.e. epiarenic). Nowhere in the world are bromeliads more dominant or have more biomass than in these coastal species growing on sand. Many of these species grow at the absolute limits of vascular plant tolerance, with the entire community consisting of a singleTillandsia species. Rooted, terrestrial bromeliads in the coastal lomas formations (allPitcairnioideae) include CAM, C3, and C3-CAM flexible taxa in their metabolic systems, the CAM species growing in the most arid sites along the coast and C3 species growing in the most mesic habitats within the center of the coastal fog belt where fog moisture input is highest. All of the epiphyticTillandsia species of the coastal desert region utilize CAM metabolism entirely or in part. At least two species,T. latifolia andT. tragophoba, utilize a flexible C3-CAM mode of carbon fixation. Whereas most of the desert-inhabitingTillandsia species have relatively narrow leaves covered by water absorbing trichomes on their surface,T. multiflora in northern Peru andT. tragophoba in northern Chile are tank-forming species where the bases of the leaves form a water-containing reservoir. The occurrence of the latter as a local endemic in hyperarid northern Chile is remarkable since it occurs thousands of kilometers south of its closest potential relatives in the central Andes.
68 citations
TL;DR: Phylogenetic analysis of nrDNA ITS and trnL (UAA) 5′ exon-trnF (GAA) chloroplast DNA sequences from 17 species of Pelargonium sect.Peristera suggests paraphyly for the section and a close relationship between the highly disjunct South African and Australian species of sect.
Abstract: Phylogenetic analysis of nrDNA ITS and trnL (UAA) 5′ exon-trnF (GAA) chloroplast DNA sequences from 17 species ofPelargonium sect.Peristera, together with nine putative outgroups, suggests paraphyly for the section and a close relationship between the highly disjunct South African and Australian species of sect.Peristera. Representatives fromPelargonium sectt.Reniformia, Ligularia s. l. andIsopetalum (the St. Helena endemicP. cotyledonis) appear to be nested within thePeristera clade. The close relationship between the South African and AustralianPeristera is interpreted as being caused by long-range dispersal to Australia, probably as recent as the late Pliocene.
67 citations
TL;DR: The peacock moraeas are South African geophytes with Iris-like flowers that are characterized by broad outer tepals with iridescent spots that were found to be exclusively visited and pollinated by beetles.
Abstract: The peacock moraeas are South African geophytes withIris-like flowers that are characterized by broad outer tepals with iridescent spots Three of the seven species were studied and found to be exclusively visited and pollinated by beetles The primary pollinators were hopliine (Scarabaeidae) beetles in the generaPeritrichia, Monochelus, Anisonyx andAnisochelus These beetles visit flowers for nectar, pollen and matingPeritrichia rufotibialis was the primary pollinator ofMoraea villosa, P abdominalis was the primary pollinator ofM tulbaghensis, whileMonochelus sp nov was the primary pollinator of the third species,M neopavonia High levels of fruit set attest to the effectiveness of these beetles as pollinators Average fruit set ranged from 835 ± 348% (M villosa) to 972 ± 116% (M tulbaghensis) Average seed set in the various populations was more variable, but was also quite high, ranging from 773 ± 408 (M villosa) to 3422 ± 1150 (M neopavonia) seeds per capsule Although hopliine beetles are abundant and diverse in southern Africa and commonly visit flowers, this is the first well-documented report of pollination by these beetles
TL;DR: In the present analysis those of these accessions which had particularly high or low DNA contents in that study were subjected to a reanalysis using propidium iodide and DAPI flow cytometry and Feulgen densitometry and no significant differences were obtained.
Abstract: A recent investigation of genome size in certain samples of the pigeonpea,Cajanus cajan, indicates values from 1.55 pg to 1.99 pg (1C level), which is 1.29-fold variation between accessions. In the present analysis those of these accessions which had particularly high or low DNA contents in that study were subjected to a reanalysis using propidium iodide and DAPI flow cytometry and Feulgen densitometry. Only minor differences in genome size, not more than 1.047-fold, were found with flow cytometry, and no significant differences were obtained with Feulgen densitometry. The previously reported genome size cannot be confirmed. It is about half as large and was determined in the present study as 0.825 pg (1C, propidium iodide flow cytometry,Glycine max as standard) and 0.853 pg (1C, Feulgen densitometry,Allium cepa andPisum sativum as standards), respectively.
TL;DR: Populations of bisexualS.
Abstract: Isozyme electrophoresis was used to study the morphologically similar sister speciesSphagnum rubellum andS. capillifolium from a sample of 1313 plants representing 37 populations from Scandinavia, Great Britain and S Germany. The mean pairwise genetic identities (I) among conspecific populations were 0.976 forS. rubellum and 0.969 forS. capillifolium, versus 0.627 between populations of the two species. Interspecific gene flow was indicated by the observation of occasional plants in sympatric populations with alleles otherwise unique to the other species. Populations of bisexualS. capillifolium were significantly more variable than populations of unisexualS. rubellum. Alpine populations ofS. rubellum andS. capillifolium were dominated by few genotypes, and differentiation among populations was pronounced, indicating a low level of sexual recombination. InS. rubellum, maximum variability was found in western areas with high annual precipitation. Distribution of alleles inS. rubellum indicated restricted gene flow between Great Britain and Scandinavia. Postglacial migration from separate refugia may explain large-scale variation inS. rubellum.
TL;DR: It is concluded that dramatic changes in family circumscriptions are needed in order for taxonomy to reflect strictly monophyletic groups in thePrimulales.
Abstract: A cladistic analysis of phylogenetic relationships in thePrimulales has been conducted, based on nucleotide sequence data from the chloroplast DNA generbcL. The analysis included 16 taxa representing all three families in the order, and also six genera from other orders, viz.Magnolia (Magnoliaceae),Caltha (Ranunculaceae),Geranium (Geraniaceae),Nicotiana (Solanaceae),Diospyros (Ebenaceae), andManilkara (Sapotaceae). Previous cladistic analyses of morphological data have indicated that theTheophrastaceae are monophyletic, and that theMyrsinaceae are paraphyletic if including the genusMaesa. The results of the present work corroborate this conclusion, but also indicate that thePrimulaceae are paraphyletic.Maesa is part of an unresolved clade that also include theTheophrastaceae and thePrimulaceae, and theMyrsinaceae s. str. The latter is part of a monophyletic group also comprising thePrimulaceae-Lysimachiinae andCyclamen. It is concluded that dramatic changes in family circumscriptions are needed in order for taxonomy to reflect strictly monophyletic groups in thePrimulales.
TL;DR: The rate of fruit set, under natural conditions and the sex ratio of the gynodioecious populations studied suggest that the hermaphrodite individuals may behave as males, and the floral biology and the phenology of Clusia nemorosa are studied.
Abstract: Between March 1993 and May 1995 the floral biology and the phenology ofClusia nemorosa
G. Mey. (Clusiaceae) were studied in two dioecious populations in Pernambuco State, and some observations were made in gynodioecious populations, that were encountered only in Bahia State. The species flowers from June to January/February. The flowers are bowl shaped, and last only one day. The floral reward is resin which is produced by staminodia in all types of flowers. The sex ratio was 1:1 for the studied populations. The pollen viability was approximately 98%. Apomixis was not observed. The rate of fruit set, in hermaphrodite individuals, under natural conditions and the sex ratio of the gynodioecious populations studied suggest that the hermaphrodite individuals may behave as males.Clusia nemorosa is melittophilous and was visited by 16 species of bees. The main pollinators wereEuplusia mussitans, E. iopyhrra, Eulaema cingulata, E. nigrita, Euglossa cordata andEuglossa sp.
TL;DR: Seed anatomy and micromorphological, wood anatomical, and floral morphological characters indicate that the taxa investigated form a monophyletic group close toMalvales s.
Abstract: Ovule and especially seed anatomy of eight species ofCochlospermaceae, Bixaceae, Cistaceae, Monotoideae, Pakaraimaeoideae (two subfamilies ofDipterocarpaceae), andSarcolaenaceae were investigated. All representatives show a bixoid chalazal region in the seed as probable exclusive synapomorphy among angiosperms. The palisade layer of the exotegmen is curved inwards at its proximal end and forms a dome-shaped structure. A plug of hypostase tissue with an annulus/core structure fits into this dome. Moreover, two additional tissue types in the hypostase can be found in some representatives of the group. These and other micromorphological, wood anatomical, and floral morphological characters, indicate that the taxa form a monophyletic group close toMalvales s. str. The form of the starch grains in the endosperm is compared and is described for the first time forPakaraimaea (Dipterocarpaceae) andLeptolaena (Sarcolaenaceae). The position ofDiegodendron close toBixa and the presumably more distant positions ofMuntingia andNeuradaceae are discussed.
TL;DR: The pollination of the terrestrial herbIrlbachia alata by the batGlossophaga soricina was recorded in northeastern Brazil and the small flowers and the delicate stem ofI.
Abstract: The pollination of the terrestrial herbIrlbachia alata by the batGlossophaga soricina was recorded in northeastern Brazil. This herb colonizes disturbed swampy sites in clearings and forest edges, blooming year-round. Its greenish white flowers open at dusk and attract phyllostomid bats and hawkmoths. The long-tongued batGlossophaga soricina is the major pollinator ofI. alata at the study site, with its trapline visits promoting cross-pollination of this herb. The small flowers and the delicate stem ofI. alata match the small size and the manoeuverable flight of glossophagine bats.
TL;DR: Fireweed is part of the South African S. inaequidens complex, and the infestation in Australia originated from South Africa as opposed to Madagascar, which will facilitate a resumption of biological control efforts in Australia and will direct surveys for control agents to South Africa.
Abstract: ITS1 sequence data was obtained for fireweed (Senecio madagascariensis) andS. lautus from Australia,S. madagascariensis andS. inaequidens from South Africa andS. madagascariensis from Madagascar. Despite the low level of variation (0.0–3.4%), these data further resolve the controversy concerning the identity and origin of fireweed. They confirm that fireweed is part of the South AfricanS. madagascariensis/S. inaequidens complex, and indicate that the infestation in Australia originated from South Africa as opposed to Madagascar. This will facilitate a resumption of biological control efforts in Australia and will direct surveys for control agents to South Africa.
TL;DR: Observations on the development and morphology of inaperturate pollen in functionally female flowers ofSolanum are related to hypotheses about the evolution of dioecy in the genus.
Abstract: Dioecy has evolved independently several times in the large, mostly tropical genusSolanum. In all cases of dioecy inSolanum functionally male flowers have normal anthers, normal pollen and reduced stigmas while functionally female flowers have stigmas and anthers that appear normal but contain non-functional, usually inaperturate pollen. The inaperturate pollen has living cytoplasm, but apparently never germinates and it has been hypothesised that the pollen in these functionally female flowers is retained as a pollinator reward. Pollen morphology is compared in twelve of the thirteen known dioecious species ofSolanum, and some stages in the the development of inaperturate pollen in the anthers of functionally female flowers ofSolanum confertiseriatum of Western Ecuador are examined. Observations on the development and morphology of inaperturate pollen in functionally female flowers ofSolanum are related to hypotheses about the evolution of dioecy in the genus.
TL;DR: Palynological data do not support a broad concept of the genus Anchusa, and point to the autonomy of the ‘satellite’ generaHormuzakia, Gastrocotyle, Phyllocara, Pentaglottis andCynoglottis.
Abstract: The results of a comparative survey on pollen morphology in theBoragineae by means of light, scanning and transmission electron microscopy are presented and discussed in relation to the taxonomy of the tribe. Multivariate analyses lead to the recognition of 15 pollen morphotypes for which a discriminant key is proposed. The discriminatory characters concern mainly the stereostructural and ultrastructural features of the grains, such as tectum sculpture and aperture morphology, while the number of apertures appears variable within genera and even single species. Seven out of the 12 investigated genera, as currently circumscribed, are matched by palynological data:Anchusella, Borago, Brunnera, Elizaldia, Lithodora, Symphytum andTrachystemon. On account of aperture shape,Lithodora is however closer to theLithospermeae than to theBoragineae. Other genera, and in particularNonea, show a wide variation in tectum ornamentation, shape of grains and number of apertures. Palynological data do not support a broad concept of the genusAnchusa, and point to the autonomy of the ‘satellite’ generaHormuzakia, Gastrocotyle, Phyllocara, Pentaglottis andCynoglottis.
TL;DR: Cladistic analysis of the data indicates that Ulmaceae s.
Abstract: The Ulmaceae is usually split into two subgroups, referred to as either tribes or more commonly subfamilies (Ulmoideae andCeltidoideae). The two groups are separated, with some exceptions, on the basis of leaf venation, fruit type, seed morphology, wood anatomy, palynology, chemistry, and chromosome number. Propositions to separate the two groups as distinct families have never gained general acceptance. Recent morphological and anatomical data have suggested, however, that not only is family status warranted but thatCeltidaceae are more closely related toMoraceae and otherUrticales than toUlmaceae. In order to test these alternative sets of relationships, restriction site mapping of the entire cpDNA was done with nine rare cutting enzymes using 11 genera ofUlmaceae s. l., three other families of theUrticales, and an outgroup family from theHamamelidae. Cladistic analysis of the data indicates thatUlmaceae s. l. is not monophyletic and that distinct families (Ulmaceae andCeltidaceae) are warranted; thatUlmaceae is the sister group toCeltidaceae plus all other families in the order; and thatCannabaceae might be nested withinCeltidaceae. Familial placements of various problematic genera (e.g.Ampelocera, Aphananthe) are resolved and character evolution of key morphological, anatomical, chemical, and chromosomal features are discussed.
TL;DR: The genome size and base composition of the triploidCrocus sativus and its two diploid most probable ancestors,C.
Abstract: The genome size and base composition of the triploidCrocus sativus and its two diploid most probable ancestors,C. cartwrightianus andC. thomasii, was investigated and compared inter- and intra-specifically by means of flow cytometry. There was little variation inC. sativus and little difference fromC. cartwrightianus. Crocus thomasii was significantly different from the others.Crocus cartwrightianus is the most probable diploid ancestor ofC. sativus.
TL;DR: The discovery of this new, allopolyploid species suggests that hybridization is an important evolutionary process in liverworts, and is likely to be an interspecific hybrid between P. platyphylla and P. cordaeana.
Abstract: Porella platyphylla andP. cordaeana are genetically well differentiated in Europe (I = 0.486). Isozyme data from 156 European colonies reveal thatP. baueri is polyploid and could be an interspecific hybrid between these two species. It is characterized by large lobe cells, toothed margins of the female bracts, and ciliate perianth mouth. Correspondence analysis using morphological characters revealed that its colonies cluster into two geographicallý separated groups, similar to one or other of the putative parental species. These results agree with the genetic analysis, that also revealed two main allelic associations, each with a distinct geographical range. We hypothesize that this pattern was produced by introgression subsequent to hybridization, or by gene silencing. The discovery of this new, allopolyploid species suggests that hybridization is an important evolutionary process in liverworts.
TL;DR: The analysis suggests that the prototunicate ascus in the Sphaerophoraceae is a reversion to the plesiomorphic state, which supports the Lecanorales as monophyletic, including Sphaenoraceae and thePeltigerineae, but does not provide strong support for this monophyly.
Abstract: SSU rDNA was sequenced from the lichenized fungiBunodophoron scrobiculatum andLeifidium tenerum (Sphaerophoraceae), andStereocaulon ramulosum andPilophorus acicularis (Stereocaulaceae) and analysed by maximum parsimony with 44 homologous ascomycete sequences in a cladistic study A small insertion (c 60 nt) was found in the sequence ofLeifidium tenerum Sphaerophoraceae constitutes a strongly supported monophyletic group which groups together withLecanora dispersa and theStereocaulaceae Together withPorpidia crustulata, this larger group is a sistergroup to thePeltigerineae This analysis thus supports theLecanorales as monophyletic, includingSphaerophoraceae and thePeltigerineae, but does not provide strong support for this monophyly The analysis also suggests that the prototunicate ascus in theSphaerophoraceae is a reversion to the plesiomorphic state Based on morphological, anatomical and chemical reasons,Sphaerophoraceae is proposed to belong to one of the groups presently included in the paraphyletic suborderCladoniineae within theLecanorales
TL;DR: The results point to the flavonoid chemistry evolution of Bignoniaceae following a path of simplification, with more complex chemical profiles characterize the more woody Tecomeae rather than the more advanced Bignonieae.
Abstract: Flavones and glycosides of flavones and flavonols were obtained from leaves of five species ofBignoniaceae from the “cerrado”, a savanna ecosystem of Central and Southeast Brazil. A predominance of flavonol glycosides was observed in all samples investigated. Flavones were often found in species of tribeTecomeae and rarely inBignonieae. The species of the former yielded derivatives of 6-hydroxyluteolin. No 6-oxygenated compounds were found in species ofBignonieae. The results point to the flavonoid chemistry evolution ofBignoniaceae following a path of simplification. More complex chemical profiles characterize the more woodyTecomeae rather than the more advancedBignonieae.
TL;DR: Morphological evolution in Exostema involves many specializations for xeric habitats, reflecting repeated ecological shifts from moist forest to exposed, seasonally dry environments during the diversification of the genus.
Abstract: The neotropical genusExostema comprises 25 species of trees and shrubs, ranging in distribution from Bolivia to Mexico and throughout the West Indies, with most species endemic to the Greater Antilles. Infrageneric relationships and species-level patterns of evolution were investigated in phylogenetic analyses using morphological, molecular, and combined data sets. All data sets resolved three main species groups which correspond to the three sections recognized byMcDowell (1996). However, the analyses of ITS sequence data placed the two South American species basal to the three main clades. Otherwise, the morphological and molecular data are highly compatible, and produce a more robust yet consistent phylogeny in the combined data analysis. Morphological evolution inExostema involves many specializations for xeric habitats, reflecting repeated ecological shifts from moist forest to exposed, seasonally dry environments during the diversification of the genus. Both moth and bee pollination syndromes are found inExostema, and shifts in pollination ecology appear pivotal to the differentiation of the three sections. Biogeographically,Exostema likely originated in South America and migrated via Central America to the Greater Antilles, where the morphological diversification and speciation are most extensive.
TL;DR: The annual Mediterranean herbTheligonum cynocrambe shows a peculiar combination of morphological characters, e.g., switch from decussate to spiral phyllotaxis with 90–100° divergence, combined with a change from interpetiolar to lateral stipules, anemophily, lack of calyx, flowers often dimerous to trimerous, corolla fused in both male and female flowers
Abstract: The annual Mediterranean herbTheligonum cynocrambe shows a peculiar combination of morphological characters, e.g., switch from decussate to spiral phyllotaxis with 90–100° divergence, combined with a change from interpetiolar to lateral stipules, anemophily, lack of calyx, flowers often dimerous to trimerous, corolla fused in both male and female flowers, male flowers extra-axillary, with 2–19 stamens per flower, female flowers axillary, with inferior uniovulate ovary, basilateral style and perianth, nut-like fruits with elaiosome. In male flowers the androecium emerges as an (uneven) elliptical rim with a central depression. This common girdling primordium is divided up into several stamen primordia. In male flowers with low stamen number the stamen primordia may occupy the corners alternating with the corolla lobes. There are no epipetalous androecial primordia that secondarily divide into stamens. Male flowers occasionally show a hemispherical base that may be interpreted as remnant of the inferior ovary. In female flowers a ring primordium grows into a tube on which the petal lobes arise. The perianth and style become displaced adaxially by uneven growth of the inferior ovary. The ovary is basically bilocular. The lower region of the ovary is provided with a septum that is overtopped and hidden by the single curved ovule.Theligonum is referred to theRubiaceae-Rubioideae, with theAnthospermeae andPaederieae as most closely related tribes.
TL;DR: Polyphyletic lines from evergreen to deciduous taxa are document and Tertiary transcontinental connections within the genus Quercus are suggested and partly conflict with current taxonomic classification but are supported by some anatomical and morphological characters.
Abstract: Nucleotide sequences from the internal transcribed spacer (ITS) regions of the 18S–26S nuclear ribosomal DNA have been studied from ten species ofQuercus (representing four subgenera),Castanea sativa andFagus sylvatica, as a preliminary molecular contribution to the still poorly understood systematics and evolution ofFagaceae. The resulting matrix has been used to calculate pair-wise sequence divergence indices and to construct a maximum parsimony tree forQuercus coding indels as a fifth state. Divergence is greater forQuercus vs.Fagus than forQuercus vs.Castanea. The tree for theQuercus taxa studied reveals two clearly divergent clades. In clade I the evergreen W MediterraneanQ. suber appears in a basal position as sister to more distal deciduous taxa, i.e. the E MediterraneanQ. macrolepis and the E AsiaticQ. acutissima (all formerly united as different sections under the apparently polyphyletic subg.Cerris), andQ. rubra (a representative of the N American subg.Erythrobalanus), forming a pair withQ. acutissima. In clade II the evergreen southeastern N AmericanQ. virginiana is basal and sister to the remaining three branches, i.e. a pair of evergreen Mediterranean taxa withQ. ilex andQ. coccifera (subg.Sclerophyllodrys), the deciduous but otherwise plesiomorphic SE European/SW AsiaticQ. cerris (type species of subg.Cerris), and the related but more apomorphic European pairQ. petraea andQ. robur (subg.Quercus). These results partly conflict with current taxonomic classification but are supported by some anatomical and morphological characters. They document polyphyletic lines from evergreen to deciduous taxa and suggest Tertiary transcontinental connections within the genus.
TL;DR: It is concluded that flavonoids are plesiomorphic characters inAloe reflecting ancient phylogenetic and biogeographic links.
Abstract: A chemotaxonomic study of practically all the species of the genusAloe showed that flavonoids occur as major compounds in 31 out of a total of 380 species investigated. Flavanones and dihydroflavonols are present in the exudate of species inAloe ser.Rhodacanthae andSuperpositae and also in a number of the endemic species from Madagascar. Flavones occur as the only major compound in the leaf extracts of the sects.Leptoaloe andGraminialoe. In ser.Macrifoliae and inLomatophyllum, the sister genus ofAloe, isovitexin co-occurred with theC-glucosylanthrone aloin. The chemotaxonomic implication of these results are discussed together with the significance of the taxonomic and chemogeographical distribution of flavonoids inAloe. With a few rare exceptions, the leaf compounds from two different biogenetic pathways (polyketide pathway and flavonoid pathway) are mutually exclusive. Since flavonoids are restricted to the basal groups inAloe, we conclude that flavonoids are plesiomorphic characters inAloe reflecting ancient phylogenetic and biogeographic links.
TL;DR: The results suggest that the analysed species of Ranunculus are divisible into two main clades, and only few of the traditional sections and subgenera ofRan unculus are monophyletic.
Abstract: A chloroplast DNA restriction site map forRanunculus sceleratus (Ranunculaceae) was constructed using 14 restriction endonucleases. The total size of the chloroplast genome is 152.4kb. No inversions were detected relative to the tobacco chloroplast DNA. Cladistic analyses of chloroplast DNA restriction site polymorphism were employed in order to elucidate the phylogeny among 76 species of the genusRanunculus in a wide sense and one species ofTrautvetteria. A total of 341 informative restriction site changes were detected. Parsimony jackknifing, bootstrapping and decay analysis were undertaken in order to evaluate the amount of support for the monophyletic groups. The results suggest that the analysed species ofRanunculus are divisible into two main clades. Only few of the traditional sections and subgenera ofRanunculus are monophyletic. The genusTrautvetteria is nested within a clade comprising, e.g.Ranunculus cymbalaria, R. andersonii, R. lapponicus andR. ficaria. SubgenusBatrachium lies within a larger clade containing, e.g.R. sceleratus andR. hyperboreus. Contractions of the inverted repeat due to parallel deletions of 200–300 bp close to the JSB have occurred in many clades and the phylogenetic distribution of this size reduction was mapped among the species.