Chloroplastrps16 intron phylogeny of the tribeSileneae (Caryophyllaceae)

Intron sequences of the chloroplast generps16 from 46 species were used to examine phylogenetic relationships indicated by nrDNA ITS sequence variation in the tribeSileneae (Caryophyllaceae, Caryophylloideae). This region has previously not been utilized for phylogenetic purposes but the results presented here suggest that it is a consistent and valuable complement to the ITS sequences. Therps16 intron trees are largely congruent with the ITS trees. All the major hypotheses suggested by the ITS data are supported, often at similar bootstrap levels. The joint usage ofrps16 intron and ITS sequences provides a powerful tool for resolving many of the difficult taxonomic issues in the tribeSileneae. Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday     

ITS sequences from nuclear rDNA suggest unexpected phylogenetic relationships between Euro-Mediterranean, East Asiatic and North American taxa ofQuercus (Fagaceae)

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.     

Molecular phylogeny ofSalicaceae and closely relatedFlacourtiaceae: Evidence from 5.8 S, ITS 1 and ITS 2 of the rDNA

A ribosomal DNA region, including the entire 5.8S RNA gene and the internal transcribed spacers ITS 1 and ITS 2, was used for studying the phylogeny ofSalicaceae and the relationship betweenSalicaceae andFlacourtiaceae. The length of the ITS regions withinSalicaceae andFlacourtiaceae was similar to that found in other angiosperms. The GC content of both ITS regions was high, varying 62.7-72.2%. The most parsimonious tree clusters the wind-pollinatedChosenia bracteosa among theSalix species, suggesting that it should be included in the genusSalix. The grouping withinSalix leaves subg.Salix as paraphyletic, for which reason the subgeneric division is questionable.Populus was monophyletic and formed a sister group toSalix. The interspecific variation of the ITS sequences was very small inSalicaceae, which is in contradiction to the age of the group according to the evidence from fossil data.Idesia polycarpa fromFlacourtiaceae shows great sequence similarity withSalicaceae, but the analysis of 5.8S rDNA supports monophyly of the four species ofFlacourtiaceae sampled for this study.     

The use of a non-coding region of chloroplast DNA in phylogenetic studies of the subtribeSonchinae (Asteraceae:Lactuceae)

The systematic utility of sequences from a non-coding region of chloroplast DNA (cpDNA) betweenpsbA andtrnH^(GUG) was examined by assessing phylogenetic relationships in subtribeSonchinae (Asteraceae:Lactuceae). Primers constructed against highly conserved regions of tRNA genes were used for PCR amplification and sequencing. ThepsbA-trnH intergenic spacer contains several insertions and deletions (indels) inSonchinae with the length varying from 385 to 450 bp. Sequence divergence ranges from 0.00% to 7.54% withinSonchinae, with an average of 2.4%. Average sequence divergence inSonchus subg.Sonchus is 2.0%, while the mean for subg.Dendrosonchus and its close relatives in Macaronesia (the woodySonchus alliance) is 1.0%. Our results suggest that this region does not evolve rapidly enough to resolve relationships among closely related genera or insular endemics in theAsteraceae. The phylogenetic utility ofpsbA-trnH sequences of the non-coding cpDNA was compared to sequences from the ITS region of nuclear ribosomal DNA. The results suggest that ITS sequences evolve nearly four times faster thanpsbA-trnH intergenic spacer sequences. Furthermore, the ITS sequences provide more variable and phylogenetically informative sites and generate more highly resolved trees with more strongly supported clades, and thus are more suitable for phylogenetic comparisons at lower taxonomic levels than thepsbA-trnH intergenic chloroplast sequences.     

Pollen morphology of the cypripedioid orchids

Pollen morphology of the four traditional genera (Paphiopedilum, Selenipedium, Cypripedium, Phragmipedium) comprising the cypripedioid orchids indicates that the monads are sulcate, more or less smooth-surfaced, and covered by a non-acetolysis resistant layer called elastoviscin. Evidence from ultrathin sections of pollen grains shows that typical exine layers are present only inSelenipedium, modified inPhragmipedium and absent inPaphiopedilum and most species ofCypripedium; that a small, inconspicuous portion of the grain surface is constructed as a sulcus; and that the pollen grain wall acts as a sponge in rapidly absorbing water. Several instances of parallelisms between non-related families and among different groups of orchids are reported and new ideas on the evolution of theCypripedioideae are presented.Dedicated to Prof. DrE. Tschermak-Woess on the occasion of her 70th birthday.Reprint requests toM. Hesse.     

Relationships between species ofLeymus,Psathyrostachys, andHordeum (Poaceae,Triticeae) inferred from Southern hybridization of genomic and cloned DNA probes

We have used total genomic DNA as a probe to size-fractionated restriction enzyme digests of genomic DNA from a range ofTriticeae species from the generaLeymus Hochst.,Psathyrostachys Nevski, andHordeum L., and hybrids betweenHordeum andLeymus to investigate their taxonomic relationships. Genomic Southern hybridization was found to be an effective and simple way to assess the distribution and diversity of essentially species-specific and common, repetitive DNA sequences, and is hence especially useful in evolutionary studies. The DNA sequences ofH. vulgare seem to diverge substantially from those ofH. brachyantherum, H. lechleri, H. procerum, andH. depressum. The genome ofThinopyron bessarabicum shows little homology to those of theLeymus species investigated, confirming thatT. bessarabicum is not an ancestral genome inLeymus. Although the genomes ofLeymus andPsathyrostachys share substantial proportions of DNA sequences, they include divergent repeated sequences as well. Hybridization with a ribosomal DNA probe (pTa 71) showed that the coding regions containing structural genes encoding the 18 S, 5.8 S, and 26 S ribosomal RNA were conserved among the species investigated, whereas the intergenic spacer region was more variable, presenting different sizes of restriction fragments and enabling a classification of the species. The rye heterochromatin probe pSc 119.2 hybridized to DNA fromH. lechleri andT. bessarabicum, but not to DNA from the other species investigated.     

The phylogenetic relationships ofByblis andRoridula (Byblidaceae-Roridulaceae) inferred from partial 18S ribosomal RNA sequences

The phylogenetic relationships of the angiosperm generaByblis andRoridula have been the subject of ongoing taxonomic controversy. Twenty-eight taxa of varying degrees of alleged relationship, including 3 members of theWinteraceae (as an outgroup), were investigated using partial sequences of 18S rRNA (small subunit) and also compared against the morphological data set fromHufford's (1992) cladistic treatment of 80 members of theRosidae-Asteridae. The morphological analysis placed the two genera in a clade with theSarraceniaceae in theCorniflorae-Asterid group as a sister taxon to anEricales-Hydrangeales clade. The 18S rRNA analysis supports the recently publishedrbcL DNA analysis ofAlbert & al. (1992), withRoridula joined to taxa in the lowerRosidae, butByblis joining instead to members of theAsteridae near theSolanaceae. Comparisons for congruence between the three analyses placeByblis in the higher Asterid group near theSolanaceae, andRoridula possibly nearer theSarraceniaceae andEricales. These results imply that the traditional morphological characters used to relate the two genera are possibly the result of convergence towards similar ecological and life-history strategies rather than synapomorphies.     

Relationships in theAcanthaceae and related families as suggested by cladistic analysis ofrbcL nucleotide sequences

A parsimony analysis of DNA sequences of the chloroplast-encoded generbcL from twelve members of theAcanthaceae s.l., including members of the sometimes segregateThunbergioideae andNelsonioideae, and other families in theBignoniales sensuThorne (1992) is presented. The results largely agree with the classification of theAcanthaceae presented byBremekamp (1965) andThorne (1992) and supportNelsonioideae as a sister group to the rest of theAcanthaceae. Thunbergioideae are placed as a sister toAcanthaceae s.str.Acanthus andAphelandra, both representatives ofAcanthoideae, form a sister group toRuellioideae. An analysis of branch support found that many branches throughout theBignoniales are weakly upheld. This points to the need for further studies in the group using more sequences ofrbcL as well as other data. None of the families ofBignoniales as presently circumscribed (includingAcanthaceae s.l.) were strongly supported, although the larger clade containing the families of theBignoniales was robust.     

Observations on pollination inSarcostemma (Asclepiadaceae)

Field observations on pollination in New World species of the genusSarcostemma R. Br. sensuHolm are reported. Morphological and anatomical comparisons of pollinated flowers ofSarcostemma subg.Ceramanthus Kuntze (New World) andSarcostemma subg.Sarcostemma (Old World) are presented.     

Adaptive radiation and genetic differentiation in the woodySonchus alliance (Asteraceae:Sonchinae) in the Canary Islands

The woodySonchus alliance consists of 19 species ofSonchus subg.Dendrosonchus, one species ofSonchus subg.Sonchus and species of five genera (i.e.Babcockia, Sventenia, Taeckholmia, Lactucosonchus, Prenanthes), and is restricted primarily to the archipelago of the Canaries in the Macaronesian phytogeographical region. An enzyme electrophoretic study, including 13 loci, was conducted to assess genetic diversity within and divergence among species of the alliance. Nei's genetic identities (distances) between genera and/or subgenera range from 0.490 (0.714) to 0.980 (0.013), and pairwise comparisons of all populations show relatively high genetic identities, with a mean of 0.804. The high identities further support the genetic cohesiveness of the alliance and its single origin on the Macaronesian islands. Species in the alliance also show about 50%; higher total genetic diversity (H_T) than the mean for other oceanic endemics. There is greater divergence between endemics or species on older islands compared to those on younger islands, which suggests that time is a factor for divergence at allozyme loci. Furthermore, populations on older islands have higher total genetic diversities and lower identities than conspecific populations on younger islands. These results imply early colonization, radiation, and divergence of the woodySonchus alliance on older islands followed by subsequent colonization to younger islands. The taxonomic distribution of alleles in the alliance indicates lineage sorting also played a role in divergence among species. Lineage sorting may also produce nonconcordance with either taxonomic designation or the pattern of variation obtained from other molecular markers such as ITS sequences of nrDNA. Timing for the origin and radiation of the alliance agrees with the estimate based on ITS sequences, and suggests that the early divergence and rapid radiation took place during the Late Tertiary on either Gran Canaria or Tenerife.     

RAPD patterns,nrDNA ITS sequences and morphological patterns inSilene sectionSedoideae (Caryophyllaceae)

Hierarchical patterns inSilene sect.Sedoideae were investigated using random amplified polymorphic DNA (RAPD), nucleotide sequences of the internal transcribed spacer (ITS) regions of the 18S–28S nuclear ribosomal DNA, and discrete morphological characters. All data sets firmly supported the species recognized. The RAPD data offered the best resolution at the intraspecific level, supporting the current intraspecific classifications ofS. sedoides andS. integripetala. The ITS sequences and the morphological data gave poor resolution within species, and the three data sets disagreed about the relationships among species. The signal from the RAPD data was strongest and remained when the total data set was analysed. The three data sets all support an amphiploid origin ofS. aegaea, with the strongest evidence from the ITS sequences. Incongruences among data sets as well as merits and shortcomings of each are discussed. The robustness of the results can be evaluated using perturbations of data, i.e., bootstrap and jackknife of taxa and characters. These methods should not be taken as methods of statistical inference at the taxonomic level, because unbiased sampling appears impossible. RAPD data, however, come close to being suitable for statistical estimation of hierarchies at the genome level, but several methodological problems have to be solved.     

Taxonomy and phylogeny of the tribePlucheeae (Asteraceae)

The tribePlucheeae (Benth.)A. Anderb., has been analysed cladistically by means of a computerized parsimony program (Hennig 86), using theArctotideae as outgroup. The results of the analysis are presented in a consensus tree and one cladogram. Four major monophyletic subgroups can be recognized: TheColeocoma group (3 genera), thePterocaulon group (3 genera), theLaggera group (6 genera), and thePluchea group (12 genera). All recognized genera are described and most genera are supplied with taxonomical notes including comments on their taxonomic status. Genera such asBlumea, Pluchea, andEpaltes are demonstrated to be unnatural assemblages.Monarrhenus andTessaria are both closely related to thePluchea complex. The old generic nameLitogyne Harv. has been taken up for one species ofEpaltes, the genusRhodogeron is reduced to a synonym ofSachsia, and the following new combinations are made;Litogyne gariepina (DC.)A. Anderb., andSachsia coronopifolia (Griseb.)A. Anderb.     

The natural delimitation ofCentaurea (Asteraceae: Cardueae): ITS sequence analysis of theCentaurea jacea group

Taxonomic complexity has hindered partitioning the genusCentaurea into natural subdivisions, even though it has long been recognized as an unwieldy, artificial assemblage. Most of the remaining difficulties center in theCentaurea jacea group, whose taxa share a common advanced type of pollen. Because it comprises half the species of the genusCentaurea, as well as five other disputed genera previously segregated fromCentaurea (Chartolepis, Cheirolepis, Cnicus, Grossheimia andTomanthea), theCentaurea jacea group is a significant taxonomic challenge. Newer molecular approaches are useful for resolving complex relationships because they provide more precise inferences of evolutionary relationships than traditional morphological characters. Sequences of the Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA were analyzed for a comprehensive sample of this group. Results indicated that theCentaurea jacea group is monophyletic and includes the segregated genera, but not two other genera (Oligochaeta andZoegea), whose inclusion in theCentaurea jacea group was doubtful. In addition to pollen morphology, the ITS phylogeny is also supported by karyological evidence and by good correlation with biogeographic distribution of the species. The monophyly of theCentaurea jacea group suggests that a natural delimitation ofCentaurea that minimizes nomenclatural changes is possible, but only if a new type of the genus is designated.     

Generic delimitation and phylogeny of theCarduncellus-Carthamus complex (Asteraceae) based on ITS sequences

Within the Mediterranean complexCarduncellus-Carthamus, taxonomic classification has proven problematic. Numerous attempts to clarify the relative systematic boundaries have included splittingCarduncellus andCarthamus into several genera, but none of these proposed classifications have been generally accepted. For a comprehensive resolution of the relationships within this group, we used sequences of the Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA. The results indicate that the complex should be classified into four genera:Carduncellus, Carthamus, Femeniasia andPhonus. The relationship between the western group (Carduncellus, Femeniasia andPhonus) and the eastern genusCarthamus are not resolved by analysis of ITS sequences, but the two groups are probably not close relatives. The ITS classifications corresponded with biogeography and less with morphological characters, which have also been the main source of confusion in traditional classifications. Most of the unusual morphological features in theCarduncellus-Carthamus complex appear to be reversals to ancestral character states.     

Phylogenetic relationships betweenVicia faba (Fabaceae) and related species inferred from chloroplasttrnL sequences

The chloroplasttrnL intron from 46 differentVicia accessions, representing five of the nine sections of the genusVicia subg.Vicia sensuMaxted (1991a) were amplified by the Polymerase Chain Reaction (PCR) using oligonucleotide primers homologous to conserved regions intrnL. The products fell into two distinct groups; those of approximately 250 nt and those of around 450 nt in length. Of these, products from 17 differentVicia species were cloned and their nucleotide sequences determined. Multiple alignments were assembled and phylogenetic trees constructed by the weighted least-squares distance method. ALathyrus latifolius trnL intron sequence was used as an outgroup. The resulting trees clearly group and separate the sectt.Narbonensis, Bithynica andFaba species but were less able to distinguish species from sectt.Hypechusa andPeregrinae. Based on these sequence data,V. faba appears to be more distant from sect.Narbonensis than sectt.Hypechusa andPeregrinae. The results are in general agreement with a recent treatment ofVicia subg.Vicia (Maxted 1993) and lend further support to placingV. faba in the monospecific sect.Faba.     

Phylogeny and classification ofFumariaceae, with emphasis onDicentra s. l., based on the plastid generps16 intron

The phylogeny ofFumariaceae, as inferred fromrps16 intron sequences, is compared with morphological data, and nrDNA-ITS. The different data sets are largely congruent and indicate that (1)Dicentra and the tribeCorydaleae as hitherto circumscribed are polyphyletic, (2)Lamprocapnos (=Dicentra spectabilis) is sister group to the rest of subfam.Fumarioideae, (3)Ehrendorferia, gen. nov. (=Dicentra chrysantha andD. ochroleuca) is basal in the latter group, (4) the morphologically aberrantIchtyoselmis, gen. nov. (=Dicentra macrantha) groups withDicentra s. str., (5) the genusCysticapnos should be included in the tribeFumarieae, (6)Dactylicapnos (=Dicentra subg.Dactylicapnos) is sister group toCorydalis, (7) the genusCorydalis is monophyletic, and consists of three subgenera:Chremnocapnos, stat. nov.,Sophorocapnos, stat. nov., andCorydalis. The following new combinations are validated:Ehrendorferia chrysantha, E. ochroleuca, Ichtyoselmis macrantha, andLamprocapnos spectabilis. Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday     

A new scolenaspidid (Osteostraci, Vertebrata) from the Lower Devonian of Podolia, Ukraine

Anew osteostracan genus and species,Victoraspis longicornualis n. gen., n. sp., is described based on material from Rakovets’, present day Ukraine. This new taxon shares characters with the two generaStensiopelta Denison, 1951 andZychaspis Janvier, 1985. A phylogenetic analysis supports the position ofVictoraspis as the sister group to a monophyleticStensiopelta, while the interrelationships of the various species ofZychaspis are poorly resolved. A morphometric analysis is carried out in an attempt to further resolve the taxonomic affinity. This analysis groups all examinedZychaspis species closely together, and further supports the establishment ofVictoraspis as separate genus.      

The phylogeny and taxonomy of genera Cystoderma and Cystodermella (Agaricales) based on nuclear ITS and LSU sequences

Species delimitation in Cystoderma and Cystodermella was evaluated based on ITS and LSU rDNA sequences as well as morphological data. Two species of Cystoderma are synonymised with C. carcharias and three species with C. jasonis, distinguishing the synonymised taxa as varieties of these accepted species. Analyses of partial LSU rDNA sequences revealed Cystoderma and Cystodermella as distinct monophyletic genera, with Ripartitella representing a well-supported sister group of the latter. Phaeolepiota aurea represents either an unsupported sister group or member of Cystoderma in the phylogenies based on LSU and ITS sequences rDNA data, respectively. The tribe Cystodermateae sensu Singer did not appear monophyletic according to analyses of LSU sequences. On the basis of these data, the phylogenetic relationships among most of the analyzed genera could not be resolved unequivocally.     

Phylogenetic analysis of cpDNA restriction sites andrps16 intron sequences reveals relationships among Apiaceae tribes Caucalideae, Scandiceae and related taxa

Evolutionary relationships among members of Apiaceae (Umbelliferae) tribe Caucalideae Spreng. and related taxa were inferred from maximum parsimony analyses of chloroplast DNA restriction sites andrps16 intron sequences and the results compared to an existing phylogeny for the group based on nuclear ribosomal DNA internal transcribed spacer sequences. While these three data sets were not similar in size or composition, the relationships among the shared taxa, with few exceptions, were concordant. Three major lineages are recognized, coinciding with the previously delimited Scandiceae subtribes Daucinae Dumort. (Agrocharis, Ammodaucus, Cuminum, Daucus, Orlaya, Pachyctenium, Pseudorlaya), Torilidinae Dumort. (Astrodaucus, Caucalis, Glochidotheca, Lisaea, Szovitsia, Torilis, Turgenia, Yabea), and Scandicinae Tausch (Anthriscus, Kozlovia, Myrrhis, Osmorhiza, Scandix). Included in Daucinae is representation from tribe Laserpitieae (Laser, Laserpitium, Melanoselinum, Monizia, Polylophium). Daucinae and Torilidinae arise as sister taxa in the chloroplast DNA-based phylogenies, whereas in the ITS trees relationships among the three major lineages are unresolved. Unexpectedly, three species ofFerula ally with Daucinae and Torilidinae. The position ofArtedia is equivocal, occurring either sister to Daucinae in the ITS trees, within Torilidinae in the intron trees, or sister to Torilidinae upon analysis of combined ITS and intron data.Chaetosciadium trichospermum emerges withinTorilis, and is recognized asTorilis trichosperma (L.) Spreng.     

Taxonomic separation ofKengyilia (Poaceae: Triticeae) in relation to nearest relatedRoegneria,Elymus, andAgropyron,based on some morphological characters

Based on 100 species representative of the four genera, we scored 290 herbarium specimens for a number of morphological characters. The data were subjected to canonical discriminant analysis using characters different from those in the identification key to these genera byBaum, Yen, andYang (1991). These characters collectively support the four groupsAgropyron, Kengyilia, Roegneria, andElymus as previously defined. The four groups are also supported by the linear discriminant function with an overall rate of 83% correct classification. Length of lemma awn was found to be an additional diagnostic character asAgropyron andKengyilia have lemma awns shorter than 5 mm, whereasRoegneria andElymus have longer lemma awns with very few exceptions. Length of glume awns is also a useful supplementary generic diagnostic.Agropyron andElymus have glume awns, whereas the majority of species ofKengyilia and more than half of the species ofRoegneria lack them. If a glume awn is present it is usually not longer than 1 mm.