Phylogenetics and evolution of the aphid genus Uroleucon based on mitochondrial and nuclear DNA sequences

The genus Uroleucon, and the related genus Macrosiphoniella, represent a large Tertiary radiation of aphids, with a total of about 300 species distributed throughout the world, primarily on host plant species in the family Asteraceae. A molecular phylogenetic study was conducted to identify major clades within Uroleucon and to address the cladistic validity of current subgeneric categories, the evolution of host plant associations, the age of origin, and intercontinental movements in this genus. The seventeen study species included members of the three major subgenera of Uroleucon, species from Europe and North America, one member of Macrosiphoniella, and two outgroups. Data consisted of DNA sequences for three mitochondrial regions and the nuclear gene EF1alpha, for a total of 4287 sites. Nodes supported strongly in both parsimony and maximum likelihood analyses suggest that: (1) Nearctic Uromelan are a monophyletic group branching near the base of the genus and not related to European Uromelan, (2) the New World subgenus Lambersius is possibly monophyletic but is not a tightly related group and is not closely related to other North American species, and (3) Nearctic members of subgenus Uroleucon are a closely related monophyletic group not allied with Nearctic Uromelan or Lambersius. Instead they represent a separate colonization by an Old World ancestor, as they are nested within a strongly supported clade containing European members of both subgenera Uroleucon and Uromelan. Neither of these subgenera is monophyletic. Molecular clock calculations, based on calibrations of mitochondrial divergences from other insects, suggest that Uroleucon + Macrosiphoniella is a relatively recent radiation, probably no more than 5–10 million years old. Although largely confined to Asteraceae, this clade did not radiate in parallel with its host plants. Rather, lateral movement between lineages of Asteraceae must have occurred repeatedly.     

Phylogenetic relationships among Passiflora species based on the glutamine synthetase nuclear gene expressed in chloroplast (ncpGS)

This paper presents the first molecular phylogeny of the genus Passiflora encompassing almost all sections of this large genus. The nuclear-encoded chloroplast-expressed glutamine synthetase gene (ncpGS) was used to examine the relationships among Passiflora species (passionflowers), which was then compared with the new classification proposed by Feuillet and MacDougal. The resulting Bayesian, likelihood, and parsimony trees are congruent and well supported. The 90 Passiflora species examined apparently split into eight main subgenera: Plectostemma, Granadilla, Astrophea, Deidamioides, Polyanthea, Dysosmia, Tetrapathea, and Tryphostemmatoides. These results are in overall agreement with the Feuillet and MacDougal's classification but here we propose that three additional subgenera, Polyanthea, Dysosmia, and Tetrapathea, should be maintained. We observe a striking overall correlation between the phylogenetic position of the different species and their chromosome number. The first clade contains the arborescent species of the subgenus Astrophea, with n=12. The second clade, subgenus Plectostemma, includes species from four subgenera of Killip's classification with n=6 chromosomes. The last clade, subgenus Granadilla, includes species of seven old subgenera with n=9. Subgenus Dysosmia, with a variable chromosome number of n=9-11, is considered here as a separate subgenus closely related to the subgenus Granadilla.     

Molecular phylogeny of Incarvillea (Bignoniaceae) based on ITS and trnL-F sequences

Incarvillea is a herbaceous and temperate member of Bignoniaceae, previously divided into four subgenera, Niedzwedzkia, Amphicome, Incarvillea, and Pteroscleris. Niedzwedzkia and Amphicome have in the past been treated as independent genera. Different relationships have been proposed for the four subgenera. Here, maximum parsimony analysis using ITS and trnL-F sequences resulted in similar trees and showed that the genus is monophyletic. Analysis of the combined data resulted in a single tree with five major clades highly supported and well resolved. The relationships of the five major clades are (subgenus Niedzwedzkia (Incarvillea olgae (subgenus Amphicome (subgenus Incarvillea, subgenus Pteroscleris)))). All four subgenera are well supported for monophyly, with the exception of subgenus Incarvillea, represented here by I. sinensis and I. olgae. Incarvillea olgae is not closely related to I. sinensis, a conclusion supported by morphology. The two basal monotypic subgenera are found in Central Asia. The most species-rich subgenus, Pteroscleris, has 10 species in the Himalaya-Hengduan Mountains and may have dispersed early from central Asia to eastern Asia. Short branch lengths on the molecular trees within Pteroscleris suggest a recent and rapid radiation of this rosette-forming subgenus, perhaps connected with the uplift of the Himalaya-Hengduan massif.     

Phylogenetic analysis of Phlebotomus species belonging to the subgenus Larroussius (Diptera, psychodidae) by ITS2 rDNA sequences

In the genealogy of Phlebotomus (Diptera: Psychodidae), morphological analyses have indicated that the subgenus Larroussius is a monophyletic group which is most closely related to the subgenera Transphlebotomus and Adlerius. We conducted a phylogenetic analysis of the relationships among six representative species of the subgenus Larroussius and one species representatitive of the Phlebotomus subgenus, assessing sequences of the Second Internal Transcribed Spacer (ITS2) of the ribosomal RNA (rRNA). Three of the species (P. perniciosus, P. ariasi and P. perfiliewi perfiliewi) were collected in different parts of the Mediterranean area. The trees estimated from parsimony and neighbour-joining analyses supported the monophyly of the Larroussius subgenus inferred from the morphological analysis. According to our data, P. ariasi may be a sister group to the rest of the Larroussius subgenus, although additional sequence data are needed to confirm this observation. Our results suggest that P. perniciosus and P. longicuspis are distinct species, in spite of the fact that there are only slight morphological differences. The strict congruence between the phylogeny of the Larroussius subgenus inferred from the ITS2 sequences and that based on morphological studies further confirmed the ability of the spacer sequence to identify recently-derived affiliations.     

基于ITS序列探讨杜鹃属的亚属和组间系统关系

首次报道了15种杜鹃属(Rhododendron)植物、1种杜香属(Ledum)植物和Cassiope fastigiata的内转录间隔区(ITS) (包括5.8S)序列.加上从GenBank下载的13种杜鹃属植物和Bajiaria racemosa的ITS序列,以C. fastigiata和B. racemosa为外类群,用最大简约法对杜鹃属的亚属和组间的系统关系进行了分析.结果表明: 1)杜鹃属是一个单系类群,叶状苞亚属为杜鹃属的基部类群; 2)杜香属确应归并到杜鹃属中,且与有鳞杜鹃亚属有较近的亲缘关系; 3)有鳞杜鹃亚属和杜香构成一个单系分支,该分支是其余无鳞杜鹃花的姐妹群; 4)由无鳞杜鹃花组成的一个分支的内部支持率较低,其中常绿杜鹃亚属和映山红亚属均为内部支持率很高的单系类群,而羊踯躅亚属和马银花亚属均为多系类群; 5)在马银花亚属中,长蕊杜鹃组和马银花组均分别得到强烈支持,马银花组与异蕊杜鹃亚属可能构成姐妹群关系,异蕊杜鹃亚属和马银花组组成的一个分支可能与映山红亚属构成姐妹群关系.     

Molecular phylogeny and systematic in the genus Brachycaudus (Homoptera: Aphididae): insights from a combined analysis of nuclear and mitochondrial genes

Phylogenetic relationships among members of the Aphid genus Brachycaudus (Homoptera: Aphididae) were inferred from partial sequences of mitochondrial cytochrome B oxidase (CytB), two partial fragments of mitochondrial cytochrome C oxidase subunit I (COI) and the internal transcribed spacer II (ITS2) of ribosomal DNA. Twenty-nine species, with several specimens per species, were included, representing all the historically recognized species-groups and subgenera used in the genus except the monospecific subgenus Mordvilkomemor. Results indicate that the genus Brachycaudus is a well-supported monophyletic group. While our results validate the monophyly of subgenera Thuleaphis , Appelia and Brachycaudus s. str. , they reveal two discrepancies in the classical taxonomy. First, the monotypic subgenus Nevskyaphis does not appear valid. Second, the traditionally defined Acaudus subgenus is not monophyletic. On the other hand, our phylogenetic trees corroborate Andreev's recent definition of Acaudus and Brachycaudina. However, they clearly show that the subgenera Prunaphis , Nevskyaphis and Scrophulaphis as defined by this author do not form monophyletic groups. Our results also highlight a highly supported clade that has not been discussed by previous authors; this clade could form a new subgenus, the subgenus Nevskyaphis . Finally, our study shows that molecular data and morphology meet the same limits in delimiting species groups and species themselves. Species groups in which taxonomic treatment is difficult are polytomous. Furthermore, except for one node clustering Brachycaudus s. str . and Appelia, intersubgeneric relationships remain poorly resolved even when several genes are added to the phylogenetic analysis. These results, together with previous studies in other aphid groups suggest that diversification might have been a rapid process in aphids.     

Molecular phylogeny of Lysimachia (Myrsinaceae) based on chloroplast trnL-F and nuclear ribosomal ITS sequences

Both nuclear ribosomal ITS and chloroplast trnL-F sequences were acquired for 57 species (accessions) of Lysimachia and its close relatives, and were analyzed together with sequences retrieved from databases. The results of phylogenetic analyses based on these data (separately or combined) show that Lysimachia is paraphyletic, with the monotypic genus Glaux nested deeply inside. Previous suggestions that Anagallis and Trientalis could be ingroups of Lysimachia were not corroborated by our results. The molecular phylogenies do not support the current infrageneric divisions of Lysimachia. Subgenus Lysimachia contains at least five independent lineages. The Hawaii endemic subgenus Lysimachiopsis was shown to group with subgenera Palladia and Heterostylandra, instead of subgenus Idiophyton as previously suggested. The two North American representatives of Lysimachia, subgenus Seleucia and section Verticillatae of subgenus Lysimachia are group together as the most basal clade of the genus. Parallel and independent evolutions were inferred for morphological characters that were previously used as diagnostic criteria. Molecular phylogenies do not offer clear inferences on the overall historical biogeography of Lysimachia, but Southeast Asia origins of several clades, including the Hawaiian endemic clade and the Iberian Lysimachia ephemerum are strongly supported.     

Molecular systematics of bats of the genus Myotis (Vespertilionidae) suggests deterministic ecomorphological convergences.

Based on extensive phenetic analyses, bats of the genus Myotis have been classically subdivided into four major subgenera each of which comprise many species with similar morphological and ecological adaptations. Each subgenus thus corresponds to a distinct "ecomorph" encompassing bat species exploiting their environment in a similar fashion. As three of these subgenera are cosmopolitan, regional species assemblages of Myotis usually include sympatric representatives of each ecomorph. If species within these ecomorphs are monophyletic, such assemblages would suggest extensive secondary dispersal across geographic areas. Conversely, these ecomorphological adaptations may have evolved independently through deterministic processes, such as adaptive radiation. In this case, phylogenetic reconstructions are not expected to sort species of the same ecomorph into monophyletic clades. To test these predictions, we reconstructed the phylogenetic history of 13 American, 11 Palaearctic, and 6 other Myotis species, using sequence data obtained from nearly 2 kb of mitochondrial genes (cytochrome b and nd1). Separate or combined analyses of these sequences clearly demonstrate the existence of several pairs of morphologically very similar species (i.e., sibling species) which are phylogenetically not closely related. None of the three tested subgenera constitute monophyletic units. For instance, Nearctic and Neotropical species currently classified into the three subgenera were clustered in a single, well-supported monophyletic clade. These species thus evolved independently of their ecological equivalents from the Palaearctic region. Independent adaptive radiations among species of the genus Myotis therefore produced strikingly similar evolutionary solutions in different parts of the world. Furthermore, all phylogenetic reconstructions based on mtDNA strongly supported the existence of an unsuspected monophyletic clade which included all assayed New World species plus M. brandtii (from the Palaearctic Region). This "American" clade thus radiated into a morphologically diverse species assemblage which evolved after the first Myotis species colonized the Americas. Molecular reconstructions support paleontological evidence that species of the genus Myotis had a burst of diversification during the late Miocene-early Pliocene epoch.     

Molecular systematics of Boraginaceae tribe Boragineae based on ITS1 and trnL sequences, with special reference to Anchusa s.l

BACKGROUND AND AIMS: Boragineae is one of the main tribes of Boraginaceae, but delimitation and intergeneric classification of this group are unclear and have not yet been studied using DNA sequences. In particular, phylogenetic relationships in Anchusa s.l. still need to be elucidated in order to assess its taxonomic boundaries with respect to the controversial segregate genera Hormuzakia, Gastrocotyle, Phyllocara and Cynoglottis. METHODS: Phylogenetic relationships among 51 taxa of tribe Boragineae were investigated by comparative sequencing of the trnL(UAA) intron of the plastid genome and of the ITS1 region of the nuclear ribosomal DNA. Exemplar taxa from 16 genera of Boragineae and all subgenera of Anchusa s.l. were included, along with two selected outgroups from tribes Lithospermeae and Cynoglosseae. KEY RESULTS: Phylogenies generated by maximum parsimony and combined ITS1-trnL sequences support the monophyly of the tribe and a split into two clades, Pentaglottis and the remainder of Boragineae. The latter contains two large monophyletic groups. The first consists of three moderately to well-supported branches, Borago-Symphytum, Pulmonaria-Nonea and Brunnera. In the Pulmonaria-Nonea subclade, the rare endemic Paraskevia cesatiana is sister to Pulmonaria, and Nonea appears to be paraphyletic with respect to Elizaldia. The second main group corresponds to the well-supported clade of Anchusa s.l., with the megaphyllic, polyploid herb Trachystemon orientalis as sister taxon, although with low support. Anchusa s.l. is highly paraphyletic to its segregate genera and falls into four subclades: (1) Phyllocara, Hormuzakia, Anchusa subgenus Buglossum and A. subgenus Buglossoides; (2) Gastrocotyle; (3) A. subgenus Buglossellum and Cynoglottis; and (4) A. subgenus Anchusa, Lycopsis and Anchusella. All species of Anchusa subg. Anchusa, including the South African A. capensis, are included in a single unresolved clade. Anchusa subgenus Limbata is also included here despite marked divergence in floral morphology. The low nucleotide variation of ITS1 suggests a recent partly adaptive radiation within this group. CONCLUSIONS: Molecular data show that nine of the usually accepted genera of the Boragineae consisting of two or more species are monophyletic: Anchusella, Borago, Brunnera, Cynoglottis, Gastrocotyle, Hormuzakia, Nonea, Pulmonaria and Symphytum. In addition, the tribe includes the four monotypic genera Paraskevia, Pentaglottis, Phyllocara and Trachystemon. The morphologically well-characterized segregate genera in Anchusa s.l. are all confirmed by DNA sequences and should be definitively accepted. Most of the traditionally recognized subgenera of Anchusa are also supported as monophyletic groups by both nuclear and plastid sequence data. In order to bring taxonomy in line with phylogeny, the institution of new, independent generic entities for subgenera Buglossum, Buglossellum and Buglossoides and a narrower but more natural concept of Anchusa are advocated.     

The Genus Artemisia and its Allies: Phylogeny of the Subtribe Artemisiinae (Asteraceae, Anthemideae) Based on Nucleotide Sequences of Nuclear Ribosomal DNA Internal Transcribed Spacers (ITS)

Abstract: Sequences of the internal transcribed spacers (ITS1 and ITS2) of nuclear ribosomal DNA were analysed for 44 Artemisia species (46 populations) representing all the five classical subgenera and the geographical range of the genus, 11 species from 10 genera closely related to Artemisia, and six outgroup species from five other genera of the Anthemideae. The results definitely support the monophyly of the genus Artemisia in its broadest sense (including some taxa segregated as independent genera, like Oligosporus and Seriphidium ). Eight main clades are established in this molecular phylogeny within Artemisia; they agree in part with the classical subdivision of the genus, but they also suggest that some infrageneric groups must be redefined, especially the subgenus Artemisia. The subgenera Tridentatae and Seriphidium are independent from each other. Some of the satellite genera are clearly placed within Artemisia ( Artemisiastrum, Filifolium, Mausolea, Picrothamnus, Sphaeromeria, Turaniphytum ), whereas some others fall outside the large clade formed by this genus (Brachanthemum, Elachanthemum, Hippolytia, Kaschgaria). Our results, correlated to other data such as pollen morphology, allow us to conclude that the subtribe Artemisiinae as currently defined is a very heterogeneous group. Affinities of the largest genus of the subtribe and tribe, Artemisia, and of other genera of the subtribe to some genera from other subtribes of the Anthemideae strongly suggest that subtribe Artemisiinae needs a deep revision and redefinition. Phylogenetic utility of region trnL-F of the plastid DNA in the genus Artemisia and allies was also evaluated: sequences of the trnL-F region in Artemisia do not provide phylogenetic information.     

Phylogeny of Bembidion and related ground beetles (Coleoptera: Carabidae: Trechinae: Bembidiini: Bembidiina)

The phylogeny of the large genus Bembidion and related genera is inferred from four nuclear protein-coding genes (CAD, wingless, arginine kinase, and topoisomerase I), ribosomal DNA (28S and 18S), and the mitochondrial gene cytochrome oxidase I (COI). 230 of the more than 1200 species of Bembidion are sampled, as well as 26 species of five related genera, and 14 outgroups. Nuclear copies (numts) of COI were found sparsely scattered through sampled species. The resulting phylogeny, based upon individual gene analyses and combined analyses using maximum likelihood and parsimony, is very well supported at most nodes. Additional analyses explored the evidence, and corroborate the phylogeny. Seven analyses, each with one of the seven genes removed from the combined matrix, were also conducted, and yielded maximum likelihood bootstrap trees sharing over 92% of their nodes with the original, well-resolved bootstrap trees based on the complete set of seven genes. All key nodes were present in all seven analyses missing a single gene, indicating that support for these nodes comes from at least two genes. In addition, the inferred maximum likelihood tree based on the combined matrix is well-behaved and self-predicting, in that simulated evolution of sequences on the inferred tree under the inferred model of evolution yields a matrix from which all but one of the model tree's clades are recovered with bootstrap value >50, suggesting that internal branches in the tree may be of a length to yield sequences sufficient to allow their inference. All likelihood analyses were conducted under both a proportion-invariable plus gamma site-to-site rate variation model, as well as a simpler gamma model. The choice of model did not have a major effect on inferred phylogenies or their bootstrap values. The inferred phylogeny shows that Bembidarenas is not closely related to Bembidiina, and Phrypeus is likely distant as well; the remaining genera of Bembidiina form a monophyletic group. Lionepha, formerly considered a subgenus of Bembidion, is shown to be outside of the clade of Asaphidion+Bembidion, and is separated as its own genus. B. (Phyla) obtusum is quite isolated within Bembidion, and there is some evidence that the remaining Bembidion form a clade. Within Bembidion, there are three large clades that are well-supported, the Bembidion, Odontium, and Ocydromus Series. The Bembidion Series contains Bembidion (s. str.), Notaphus, Furcacampa, Emphanes, Trepanedoris, Diplocampa, and related Holarctic species; all species from South America, Australia, New Zealand; and most species from southern Africa and Madagascar. All species in South America, except for members of Notaphus and Nothocys, form a clade, the Antiperyphanes Complex, which has independently radiated into body forms and niches occupied by multiple, independent Northern-Hemisphere forms. All species from New Zealand, including Zecillenus, and Australian species formerly placed in Ananotaphus together form a clade. Bembidion (s. str.) and Cyclolopha are in a clade with the Old World, Southern Hemisphere lineages Notaphocampa, Sloanephila, and Omotaphus. The large subgenus Notaphus appears to have originated in South America, with all Northern Hemisphere Notaphus arising from within a south-temperate grade. All major variation in frontal furrows on the head is contained within the Bembidion Series. The Odontium Series contains subgenera Hirmoplataphus and Hydriomicrus, which together are the sister clade of Odontium, Bracteon, Ochthedromus, Pseudoperyphus, and Microserrullula. The very large Ocydromus Series, dominant in the Holarctic region, includes the Ocydromus Complex, with many subgenera, including Hypsipezum and Leuchydrium; the phylogeny within this group is notably at odds with the current classification. Also included in the Ocydromus Series are Nepha and Bembidionetolitzkya, as well as the Princidium Complex, in which the intertidal B. (Cillenus) laterale falls. Outside these three series are a number of smaller groups, including the Plataphus Complex (containing Blepharoplataphus, Plataphus, the latter including Plataphodes); the Hydrium Complex (Metallina, Chlorodium, and Hydrium, which contains Eurytrachelus), whose sister group might be subgenus Andrewesa; Trechonepha and Liocosmius, which might be sisters; and B. (Melomalus) planatum, which is not close to Plataphus. There is some evidence that these groups plus the Ocydromus and Odontium Series form a clade. A few enigmatic groups were harder to place. The sister group of the pair Philochthus plus Philochthemphanes might be B. wickhami; Eupetedromus is well outside the three major series and not related to Notaphus; the high-elevation Asian group Hoquedela is a very isolated lineage. Notaphiellus is removed from synonymy with Nothocys, and placed in synonymy with Notaphus; Plataphodes is synonymized with Plataphus, as Plataphus is paraphyletic otherwise; Eurytrachelus is synonymized with Hydrium. A new subgenus, Lindrochthus, is described to house the distinctive B. wickhami. The implications of the inferred phylogeny for some morphological characters used in Bembidiina systematics are explored, and some of the most widely used (e.g., location of discal seta ed3 on the elytron, and shape of the shoulder) are shown to be notably homoplastic. For example, the location of elytral seta ed3 has undergone at least nine transitions between two states.     

Toward a better understanding of the infrageneric relationships in Cortinarius (Agaricales, Basidiomycota)

Research on the molecular systematics of Cortinarius, a species-rich mushroom genus with nearly global distribution, is just beginning. The present study explores infrageneric relationships using rDNA ITS and LSU sequence data. One large dataset of 132 rDNA ITS sequences and one combined da-taset with 54 rDNA ITS and LSU sequences were generated. Hebeloma was used as outgroup. Bayesian analyses and maximum-likelihood (ML) analyses were carried out. Bayesian phylogenetic inference performed equally well or better than ML, especially in large datasets. The phylogenetic analysis of the combined dataset with species representing all currently recognized subgenera recovered seven well-supported clades (Bayesian posterior probabilities BPP > 90%). These major clades are: /Myxacium s.l., /subg. Cortinarius, the /phlegmacioid clade (including the subclades /Phlegmacium and /Delibuti), the /calochroid clade (/Calochroi, /Ochroleuci and /Allutus), the /telamonioid clade (/Telamonia, /Orellani, /Anomali), /Dermocybe s.l. and /Myxotelamonia. Our results show that Cortinarius consists of many lineages, but the relationships among these clades could not be elucidated. On one hand, the low divergence in rDNA sequences can be held responsible for this; on the other hand, taxon sampling is problematic in Cortinarius phylogeny. Because of the incredibly high diversity (~2000 Cortinarius species), our sampling included <5% of the known species. By choosing type species of subgenera and sections, our sampling is strongly biased toward Northern Hemisphere taxa. More extensive taxon sampling, especially of species from the Southern Hemisphere, is essential to resolve the phylogeny of this important genus of ectomycorrhizal fungi.     

中国榕属榕亚属植物的系统发育初探

对分布于中国的榕亚属植物的15个种和2个变种(分别代表榕亚属的3个组)的nrDNA的ITS序列和系统发育关系进行分析。结果表明,榕亚属是非单系起源,其中榕组构成了一个独立的单系群,与无花果亚属有较近的亲缘关系,而与榕亚属其它组间并未表现出近缘关系。榕亚属的其它5个组构成一单系群并得到中度的支持率。来自中国的种类分别聚在相应的组内。但环纹榕组被分成2个单支,其中来自中国的大叶水榕(F.glaberrima)和环纹榕(F.annulata)构成一个分支,二者表现较近的亲缘关系。榕亚属的亚洲特有组印度榕组在ITS树中聚在环纹榕组的另一个分支中,但它与此组其它种的亲缘关系并不清楚。     

Phylogenetic relationships and ecological speciation in the mistletoe Tristerix (Loranthaceae): the influence of pollinators, dispersers, and hosts

Phylogenies can provide valuable information on biotic and abiotic factors associated with speciation. We examined species relationships in Tristerix (Loranthaceae), a genus of 11 species with an Andean distribution from Colombia to Chile. A previous classification divided Tristerix into subgenera Tristerix (two species) and Metastachys (nine species). We tested this classification by generating a molecular phylogeny of the genus using nuclear ribosomal DNA ITS and chloroplast atpB-rbcL intergenic spacer and trnL-F regions. All partitions generally gave congruent trees, thus a combined analysis was conducted. Tristerix was composed of a northern clade (six species) and a southern clade (four species). Tristerix verticillatus and T. penduliflorus (Metastachys) were strongly supported as members of the (southern) subgenus Tristerix clade. Speciation appears to be correlated with the emergence of matorral and cloud forest biomes and is driven by interactions with pollinators and seed dispersers. Tristerix aphyllus is sister to T. corymbosus of the matorral, not to neighboring temperate forest populations, thus rendering the latter species paraphyletic. This ecological speciation event may have occurred in sympatry. Tristerix provides excellent examples of how, during the orography of the Andes, many dynamic and interacting ecological factors have influenced their speciation.     

Phylogeny of Cyttaria inferred from nuclear and mitochondrial sequence and morphological data

Cyttaria species (Leotiomycetes, Cyttariales) are obligate, biotrophic associates of Nothofagus (Hamamelididae, Nothofagaceae), the southern beech. As such Cyttaria species are restricted to the southern hemisphere, inhabiting southern South America (Argentina and Chile) and southeastern Australasia (southeastern Australia including Tasmania, and New Zealand). The relationship of Cyttaria to other Leotiomycetes and the relationships among species of Cyttaria were investigated with newly generated sequences of partial nucSSU, nucLSU and mitSSU rRNA, as well as TEF1 sequence data and morphological data. Results found Cyttaria to be defined as a strongly supported clade. There is evidence for a close relationship between Cyttaria and these members of the Helotiales: Cordierites, certain Encoelia spp., Ionomidotis and to a lesser extent Chlorociboria. Order Cyttariales is supported by molecular data, as well as by the unique endostromatic apothecia, lack of chitin and highly specific habit of Cyttaria species. Twelve Cyttaria species are hypothesized, including all 11 currently accepted species plus an undescribed species that accommodates specimens known in New Zealand by the misapplied name C. gunnii, as revealed by molecular data. Thus the name C. gunnii sensu stricto is reserved for specimens occurring on N. cunninghamii in Australia, including Tasmania. Morphological data now support the continued recognition of C. septentrionalis as a species separate from C. gunnii. Three major clades are identified within Cyttaria: one in South America hosted by subgenus Nothofagus, another in South America hosted by subgenera Nothofagus and Lophozonia, and a third in South America and Australasia hosted by subgenus Lophozonia, thus producing a non-monophyletic grade of South American species and a monophyletic clade of Australasian species, including monophyletic Australian and New Zealand clades. Cyttaria species do not sort into clades according to their associations with subgenera Lophozonia and Nothofagus.     

Molecular evolution and phylogenetic implications of internal transcribed spacer sequences of nuclear ribosomal DNA in the Phaseolus-Vigna complex.

Molecular phylogeny based on internal transcribed spacer (ITS) sequences was studied to resolve the taxonomic contradiction in Vigna and its relation to Phaseolus. The ITS region of the 18S-26S nuclear ribosomal DNA repeat was sequenced for 29 Vigna species, selected from five of the nine subgenera, and 9 species of Phaseolus. The length of ITS-1 ranged from 187 to 243 bp and 217 to 290 bp, and that of ITS-2 from 187 to 219 bp and 225 to 243 bp, within Vigna and Phaseolus species, respectively. Phylogenies derived from ITS sequences based on maximum-parsimony and neighbor-joining methods gave trees essentially of similar topology. The ITS phylogeny was generally congruent with recent classifications based largely on morphological, biochemical, cytogenetical, and palynological features, except that subgenus Plectotropis of Neotropical origin was revealed to be closely related to subgenus Vigna instead of forming a link between African (subgenus Vigna) and Asiatic (subgenus Ceratotropis) vignas, and subgenus Sigmoidotropis, featuring morphological characters of both Vigna and Phaseolus, was placed as the sister group to the Phaseolus taxa. The ITS sequences were shown to be useful for identifying wild progenitors of V. mungo, V. radiata, V. umbellata, and V. unguiculata and for clarifying taxonomy-related problems in many previously controversial cases. This study also affirms that V. umbellata and V. angularis are the diploid progenitors of the only tetraploid species (V. glabrescens) known in the genus.     

Phylogenetics of the Thamnocalamus group and its allies (Gramineae: Bambusoideae): inference from the sequences of GBSSI gene and ITS spacer

Phylogenetics of 33 species (35 species in the ITS analysis) of the Thamnocalamus group and its allies inferred from partial sequences of the nuclear GBSSI gene and from those of the nuclear ribosomal ITS spacer was discussed in the present paper. The analyses of two separate data and combined data sets were performed using the parsimony method. Two species from Arundinaria and Acidosasa were used as outgroups. All three analyses supported the monophyly of the Thamnocalamus group and its allies, which have pachymorph rhizomes and semelauctant synflorescences with three stamens. The two sampled species of Chimonocalamus were resolved as a strongly supported monophyletic group and as basal in the Thamnocalamus group and its allies in the ITS and combined analyses. The resolution of the Thamnocalamus group and its allies in the GBSSI-gene-based tree was generally poor, while the gene still identified some clades with strongly internal supports, i.e., the Chimonocalamus clade, the Ampelocalamus clade, the clade of Thamnocalamus spathiflorus and its variety, that of Fargesia porphyrea and Yushania bojieana, and the clade of Fargesia edulis and Fargesia fungosa. The topology resulting from the GBSSI and ITS combined data analysis had a better resolution than those from the two separate data sets. T. spathiflorus and its variety comprised another strongly supported basal clade and may be next to the Chimonocalamus clade. The positions of the African Thamnocalamus tessellatus and Arundinaria (Yushania) alpina, and the monotypic Chinese endemic Gaoligongshania were problematic. The Thamnocalamus group per se was resolved as polyphyletic. Most species of Fargesia and Yushania formed a group with no bootstrap support. This assemblage was heterogeneous according to the morphological characters and further investigation is needed. This study implicated that the current limitation of three genera of Thamnocalamus, Fargesia (incl. Borinda) and Yushania may not reflect the true phylogenetic relationships of the complex. The phylogenetic utility of GBSSI gene in closely related woody bamboos was also evaluated.     

Veronica: Chemical characters for the support of phylogenetic relationships based on nuclear ribosomal and plastid DNA sequence data

Molecular phylogenetic analyses have revealed many relationships in Veronica (Plantaginaceae) never anticipated before. However, phytochemical characters show good congruence with DNA-based analyses. We have analysed a combined data set of 49 species and subspecies derived from the nuclear ribosomal ITS-region (18 new sequences) and the plastid trnL-F region (12 new sequences) of Veronica emphasizing subgenera Chamaedrys and Pocilla and separate analyses of subgenera Pentasepalae (ITS only) and Pseudolysimachium. Results for subgenus Chamaedrys show that European and Asian perennial species are monophyletic sister groups with the annual species consecutive sisters to them. All species of Veronica that contain cornoside are found in this subgenus, although some species seem to have secondarily lost the ability to produce this compound. Subgenera Pocilla and Pentasepalae are well supported sister groups characterized by the occurrence of 8-hydroxyflavones. The traditional subsection Biloba of subgenus Pocilla is biphyletic with Veronica intercedens being clearly separate from the rest of the group. This result is mirrored by the unusual phytochemical arsenal of V. intercedens, which is the only species in the genus analysed to date to contain melittoside and globularifolin. Subgenus Pentasepalae appears to be a clade of diverse lineages from southwestern Asia and a single European clade. Species shown to have 6-hydroxyflavones do not form a monophyletic group. Subgenus Pseudolysimachium seems to have originated in Eastern Asia. 6-Hydroxyflavones acylated with phenolic acids are common in this subgenus but may have originated only later in the evolution of the group. Possible chemotaxonomic markers for other groups are discussed.     

根据ITS序列证据重建防己科蝙蝠葛族的系统发育

研究了国产防己科蝙蝠葛族tirb．Menispermeae9属20种和外类群青牛胆族trib．Tinosporeae 2属3种植物完整的ITS(包括5.8S rDNA)序列。trib．Menispermeae的ITS长527～601 bp,排序后长667bp。当gap处理为missing时具281个有信息位点。PAUP软件分析结果表明：①trib．Menispermeae是一个单系类群,该分支得到hootstrap l00％的支持;②确定了存疑种Pachygone valida的系统学位置,该种是Coc—culus属的成员;③Sinomenium和Menispermum两属有很近的系统学关系,组成族内稳定的一支,它们的ITS序列同源性极高,ITS1比族内其它属长41～73bp;④Stephania和Cyclea也是系统发育关系很近的两个类群。前者具两个主要分支,其IIS1、ITS2的G+C含量差异较大,在种类组成上,该两大支与传统上Stephania属内处理的2个亚属——千金藤亚属subgen．Stephania和山乌龟亚属subgen．Tuberiphania基本一致;Cyclea属内种间的ITS序列差异小,同源性极高。