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1.
Aim We reconstructed the phylogeny of the lichen genus Nephroma (Peltigerales) to assess the relationships of species endemic to Macaronesia. We estimated dates of divergences to test the hypothesis that the species arose in Macaronesia (neo‐endemism) versus the oceanic archipelagos serving as refugia for formerly widespread taxa (palaeo‐endemism). Location Cosmopolitan with a special focus on the archipelagos of the Azores, Madeira and the Canary Islands. Methods DNA sequences were obtained from 18 species for three loci and analysed using maximum parsimony, maximum likelihood and Bayesian inferences. Divergence dates were estimated for the internal transcribed spacer (ITS)‐based phylogeny using a relaxed molecular clock. Reconstruction of the ancestral geographical range was conducted using the Bayesian 50% majority rule consensus tree under a parsimony method. Results The backbone phylogenetic tree was fully supported, with Nephroma plumbeum as sister to all other species. Four strongly supported clades were detected: the Nephroma helveticum, the N. bellum, the N. laevigatum and the N. parile clades. The latter two share a common ancestor and each includes a widespread Holarctic species (N. laevigatum and N. parile, respectively) and all species endemic to Macaronesia. The data suggest a neo‐endemic origin of Macaronesian taxa, a recent range expansion from Macaronesia of both widespread species, a range expansion limited to the Mediteranean Basin and south‐western Europe for another taxon, and a long dispersal event that resulted in a speciation event in the western parts of North America. Main conclusions The Macaronesian endemic species belong to two sister clades and originated from a most recent common ancestor (MRCA) shared with one widely distributed taxon, either N. parile or N. laevigatum. Estimates of the mean divergence dates suggest that the endemics originated in the archipelagos after the rise of the volcanic islands, along with the ancestor to the now widespread species, which probably expanded their range beyond Macaronesia via long‐distance dispersal. This study provides the first phylogenetic evidence of Macaronesian neo‐endemism in lichenized fungi and provides support for the hypothesis that oceanic islands may serve as a source for the colonization of continents. However, further data are needed to properly assess the alternative hypothesis, namely colonization from western North America.  相似文献   

2.
A multi-locus phylogenetic study of the order Arthoniales is presented here using the nuclear ribosomal large subunit (nuLSU), the second largest subunit of RNA polymerase II (RPB2) and the mitochondrial ribosomal small subunit (mtSSU). These genes were sequenced from 43 specimens or culture isolates representing 33 species from this order, 16 of which were from the second largest genus, Opegrapha. With the inclusion of sequences from GenBank, ten genera and 35 species are included in this study, representing about 18 % of the genera and ca 3 % of the species of this order. Our study revealed the homoplastic nature of morphological characters traditionally used to circumscribe genera within the Arthoniales, such as exciple carbonization and ascomatal structure. The genus Opegrapha appears polyphyletic, species of that genus being nested in all the major clades identified within Arthoniales. The transfer of O. atra and O. calcarea to the genus Arthonia will allow this genus and family Arthoniaceae to be recognized as monophyletic. The genus Enterographa was also found to be polyphyletic. Therefore, the following new combinations are needed: Arthonia calcarea (basionym: O. calcarea), and O. anguinella (basionym: Stigmatidium anguinellum); and the use of the names A. atra and Enterographa zonata are proposed here. The simultaneous use of a mitochondrial gene and two nuclear genes led to the detection of what seems to be a case of introgression of a mitochondrion from one species to another (mitochondrion capture; cytoplasmic gene flow) resulting from hybridization.  相似文献   

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5.
The closely related genera Carestiella, Schizoxylon and Stictis (Stictidaceae, Ostropales, Ascomycota) are revised in northern Scandinavia, and a revised phylogenetic hypothesis, including all seven species of this group in the area, is presented. A key to the species of Stictis s. lat. (including Carestiella, Schizoxylon and Stictis) in Northern Scandinavia is presented. S. albescens and S. confusum are described as new to science, and the new name S. brunnescens is introduced for S. mollis ssp. populorum, when treated as a distinct species. C. socia and S. albescens are the only representatives of their genera in northern Scandinavia, but a total of five species of Stictis are present in the area (S. brunnescens, S. confusum, S. mollis, S. populorum and S. radiata). Substantial within-species variation in ascoma morphology and wall pigmentation is revealed and discussed, and found to correlate with fungal lifestyles; optional lichenization apparently affects several details in fungal anatomy and morphology.  相似文献   

6.
A new genus of Metopiinae, Ojuelos Khalaim, gen. n., with a single species, Ojuelos juachicus Khalaim & Ruíz-Cancino, sp. n., is described from Jalisco Province in central Mexico. Ojuelos belongs to the group of three genera (Cubus Townes & Townes, Colpotrochia Holmgren and Triclistus Förster) having a high lamella separating the antennal sockets and reaching the median ocellus (this lamella possesses a dorsal groove in it, just below the median ocellus), but differs from these genera primarily by 1) face and clypeus not convex in lateral view, 2) face separated from clypeus by a shallow transverse impression, 3) mandible with lower tooth very strongly reduced, 4) flagellomeres of antenna strongly transverse, and 5) dorsal carinae of propodeum reduced. A portion of the key to the genera of Metopiinae is provided to distinguish the new genus.  相似文献   

7.
To clarify the relationship between two genera, Draba and the narrow genus Coelonema, endemic to the QilianMountains of the northeastern Qinghai-Tibet Plateau, phylogenetic analyses were conducted using nuclear ribosomal DNA ITS, and the chloroplast DNA trnL, from Coelonema draboides and 30 species of Draba representing eight sections, including 25 species of Chinese Draba, seven of which were endemic to the study region. The results unambiguously support several previously published proposals to unite Coelonema with Draba and accommodate C. draboides in the latter genus on the basis of morphological re-examination. Our molecular data presented here also provide evidence that these two genera should be combined as a monophyletic group with high support. In addition, it is estimated that Draba may have originated about 1.36–2.71 Mya, with C. draboides diverging from Draba about 0.15–0.31 Mya, based on the molecular calibration of ITS datasets. The assumed speciation and rapid expansion of these two genera is likely to have occurred in the eastern edge of the QilianMountains area according to molecular phylogeny and estimated divergence times, which correspond well with the known geological and paleobotanical histories of the Qinghai-Tibet Plateau.  相似文献   

8.

Background and Aims

The genus Erodium is a common feature of Mediterranean-type climates throughout the world, but the Mediterranean Basin has significantly higher diversity than other areas. The aim here is to reveal the biogeographical history of the genus and the causes behind the evolution of the uneven distribution.

Methods

Seventy-eight new nrITS sequences were incorporated with existing plastid data to explore the phylogenetic relationships and biogeography of Erodium using several reconstruction methods. Divergence times for major clades were calculated and contrasted with other previously published information. Furthermore, topological and temporal diversification rate shift analyses were employed using these data.

Key Results

Phylogenetic relationships among species are widely congruent with previous plastid reconstructions, which refute the classical taxonomical classification. Biogeographical reconstructions point to Asia as the ancestral area of Erodium, arising approx. 18 MYA. Four incidences of intercontinental dispersal from the Mediterranean Basin to similar climates are demonstrated. Increases in diversification were present in two independent Erodium lineages concurrently. Two bursts of diversification (3 MYA and 0·69 MYA) were detected only in the Mediterranean flora.

Conclusions

Two lineages diverged early in the evolution of the genus Erodium: (1) subgenus Erodium plus subgenus Barbata subsection Absinthioidea and (2) the remainder of subgenus Barbata. Dispersal across major water bodies, although uncommon, has had a major influence on the distribution of this genus and is likely to have played as significant role as in other, more easily dispersed, genera. Establishment of Mediterranean climates has facilitated the spread of the genus and been crucial in its diversification. Two, independent, rapid radiations in response to the onset of drought and glacial climate change indicate putative adaptive radiations in the genus.  相似文献   

9.
Gomaa F  Todorov M  Heger TJ  Mitchell EA  Lara E 《Protist》2012,163(3):389-399
The systematics of lobose testate amoebae (Arcellinida), a diverse group of shelled free-living unicellular eukaryotes, is still mostly based on morphological criteria such as shell shape and composition. Few molecular phylogenetic studies have been performed on these organisms to date, and their phylogeny suffers from typical under-sampling artefacts, resulting in a still mostly unresolved tree. In order to clarify the phylogenetic relationships among arcellinid testate amoebae at the inter-generic and inter-specific level, and to evaluate the validity of the criteria used for taxonomy, we amplified and sequenced the SSU rRNA gene of nine taxa - Difflugia bacillariarum, D. hiraethogii, D. acuminata, D. lanceolata, D. achlora, Bullinularia gracilis, Netzelia oviformis, Physochila griseola and Cryptodifflugia oviformis. Our results, combined with existing data demonstrate the following: 1) Most arcellinids are divided into two major clades, 2) the genus Difflugia is not monophyletic, and the genera Netzelia and Arcella are closely related, and 3) Cryptodifflugia branches at the base of the Arcellinida clade. These results contradict the traditional taxonomy based on shell composition, and emphasize the importance of general shell shape in the taxonomy of arcellinid testate amoebae.  相似文献   

10.
11.
The Nearctic genus Prostoia (Plecoptera: Nemouridae) is reviewed. Prostoia ozarkensissp. n. is described from the male and female adult stages mainly from the Interior Highland region encompassing portions of Arkansas, Missouri, and Oklahoma. Prostoia ozarkensissp. n. appears most closely related to two species, one distributed broadly across the western Nearctic region, P. besametsa (Ricker), and one found widely throughout the central and eastern Nearctic regions, P. completa (Walker). A surprising range extension is noted for P. hallasi Kondratieff & Kirchner, a species once known only from the Great Dismal Swamp, from small upland streams in southern Illinois. Additional new state records are documented for P. besametsa, P. completa, P. hallasi and P. similis (Hagen). Taxonomic keys to Prostoia males and females are provided, and scanning electron micrographs of adult genitalia of all species are given.  相似文献   

12.
The effect of the combined use of Encarsia formosa or Macrolophus caliginosus and one of three marketed mycoinsecticides, Mycotal® (Leucanicillium muscarium-based), Naturalis-L™ (Beauveria bassiana-based) and PreFeRal® (Isaria fumosorosea-based), on the control of the whitefly, Trialeurodes vaporariorum, was studied under laboratory and greenhouse conditions. The results of both types of tests, the bioassays and the greenhouse trials, for all combinations of E. Formosa with each of the three mycoinsecticides showed that the total mortality of larval populations of T. vaporariorum was not affected. The mortality of T. vaporariorum larvae treated in the second instar revealed the capacity for both B. bassiana- and L. muscarium-based formulations and E. formosa to kill the host either separately or in association. Because of its higher pathogenic activity (under our test conditions), L. muscarium provoked a large proportion of mycoses in larvae exposed to parasitization. In contrast, the efficacy of parasitization was higher in larvae treated with B. bassiana and exposed to E. formosa because of a lower pathogenic activity of the fungus. Bioassays carried out with third-instar larvae of T. vaporariorum showed a low susceptibility to both tested fungi. Consequently, mortalities recorded in larvae subjected to the combined treatments by consecutive exposures or at 2-4 days post-parasitization were mainly caused by the development of the parasitoid. Greenhouse trials showed that fungus-induced mortality of T. vaporariorum in plants treated with L. muscarium, I. fumosorosea, and B. Bassiana was significant compare to control. L. muscarium, B. bassiana and I. fumosorosea killed young whitefly larvae and limited parasitization to 10% or less. Second-instar larvae of M. caliginosus were not susceptible to L. muscarium and B. bassiana formulations with any mode of contamination: direct spraying of larvae, spraying on the foliar substrate or by contaminated T. vaporariorum prey. In greenhouse trials, M. caliginosus populations treated with fungi were not significantly affected compared to controls.  相似文献   

13.
In this study, we investigated Rickettsia infection in Chinese wheat pest aphid (Sitobion miscanthi), moreover detected a possibly new Rickettsia-like symbiont, provisionally named as SMLS1 (S. miscanthi L type symbiont). The sequence of SMLS 16S rRNA gene is 94% similar to that of its presumed closest relative, Orientiatsutsugamushi. If levels of divergence indicate taxonomic distinctiveness, SMLS probably represents a new genus in the family Rickettsiaceae. SMLS occurs in most populations of S. miscanthi, and with divergent infection frequencies, from 5.0% to 93.8%.  相似文献   

14.
Lygodium microphyllum, first naturalized in the 1960s, has aggressively invaded forest-dominated wetlands in southern and central Florida. The indeterminate growth of this invasive climbing fern creates thick rachis mats which climb over shrubs and trees smothering the underlying growth and carrying ground fires into the forest canopy. Foreign surveys for natural enemies identified 20 species of insects and two species of mites. Host range testing of three insect species and one mite included five Lygodium species (L. palmatum, L. volubile, L. cubense, L. venustum, and L. oligostachyum) native to the United States and the West Indies. A molecular phylogeny of the genus was conducted using the trnL intron and the trnL-F intergenic spacer of chloroplast DNA to determine the relationship of L. microphyllum to other Lygodium species. Three major clades appeared, one with L. palmatum and L. articulatum (the most basal), a second with L. reticulatum and L. microphyllum, and a third comprising the other species examined. Lygodium microphyllum appeared at the end of a long branch approximately equidistant from all species of interest preventing the correlation of genetic distance and host range behavior. However, inspection of the results of host range experiments showed a relationship between the presence of a related biotype or species of the insect on a related alternate host and the ability of that insect to develop on that alternate host. Ancestral host usage and ecological fitting are examined as possible explanations for the acceptance of L. palmatum by the tested musotimine insects.  相似文献   

15.
Long-eared bats of the genus Plecotus are widespread and common over most of the western Palaearctic. Based on recent molecular evidence, they proved to represent a complex of several cryptic species, with three new species being described from Europe in 2002. Evolutionary relationships among the different lineages are still fragmentary because of the limited geographic coverage of previous studies. Here we analyze Plecotus mitochondrial DNA sequences from the entire Mediterranean region and Atlantic Islands. Phylogenetic reconstructions group these western Palaearctic Plecotus into two major clades which split at least 5 Myr ago and that are each subdivided into further subgroups. An 'auritus group' includes the traditional P. auritus species and its sister taxon P. macrobullaris (=P. alpinus) plus related specimens from the Middle East. P. auritus and P. macrobullaris have broadly overlapping distributions in Europe, although the latter is apparently more restricted to mountain ranges. The other major clade, the 'austriacus group,' includes the European species P. austriacus and at least two other related taxa from North Africa (including P. teneriffae from the Canary Islands), the Balkans and Anatolia (P. kolombatovici). The sister species of this 'austriacus group' is P. balensis, an Ethiopian endemic. Phylogenetic reconstructions further suggest that P. austriacus reached Madeira during its relatively recent westward expansion through Europe, while the Canary Islands were colonized by a North African ancestor. Although colonization of the two groups of Atlantic Islands by Plecotus bats followed very distinct routes, neither involved lineages from the 'auritus group.' Furthermore, the Strait of Gibraltar perfectly segregates the distinct lineages, which confirms its key role as a geographic barrier. This study also stresses the biogeographical importance of the Mediterranean region, and particularly of North Africa, in understanding the evolution of the western Palaearctic biotas.  相似文献   

16.
Ferris CD 《ZooKeys》2010,(71):49-70
Based on genitalic studies, the new genus Pionenta is established for two taxa formerly placed under Antepione. The taxa hewesata and ochreata (and previously associated synonyms) are now synonomized as Pionenta ochreata. Three species of Antepione are now recognized: Antepione thisoaria, Antepione imitata, Antepione tiselaaria with the taxa comstocki, constans, and indiscretata synonomized under Antepione imitata. No new species are described. Adults and genitalia are illustrated, including type specimens.  相似文献   

17.
Vigna unguiculata was introduced into Europe from its distribution centre in Africa, and it is currently being cultivated in Mediterranean regions with adequate edapho-climatic conditions where the slow growing rhizobia nodulating this legume have not yet been studied. Previous studies based on rrs gene and ITS region analyses have shown that Bradyrhizobium yuanmingense and B. elkanii nodulated V. unguiculata in Africa, but these two species were not found in this study. Using the same phylogenetic markers it was shown that V. unguiculata, a legume from the tribe Phaseolae, was nodulated in Spain by two species of group I, B. cytisi and B. canariense, which are common endosymbionts of Genisteae in both Europe and Africa. These species have not been found to date in V. unguiculata nodules in its African distribution centres. All strains from Bradyrhizobium group I isolated in Spain belonged to the symbiovar genistearum, which is found at present only in Genisteae legumes in both Africa and Europe. V. unguiculata was also nodulated in Spain by a strain from Bradyrhizobium group II that belonged to a novel symbiovar (vignae). Some African V. unguiculata-nodulating strains also belonged to this proposed new symbiovar.  相似文献   

18.
Messer PW 《ZooKeys》2011,(147):419-424
The Mexican carabid species Pseudaptinus (Thalpius) nobilis Liebke is documented from the United States for the first time based on two specimens captured in southeastern Texas. A new taxonomic key distinguishes the 10 members of subgenus Thalpius known in North America, including Mexico. Pseudaptinus (Thalpius) dorsalis, which is found to be highly variable in its dorsal coloration, is compared to similar Pseudaptinus (Thalpius) hoegei. Geographic ranges are extended for several species.  相似文献   

19.
R180, isolated from porcine brain cortex, is a high-affinity membrane receptor for ammodytoxin A (AtxA), a secreted phospholipase A(2) (sPLA(2)) and presynaptically active neurotoxin from venom of the long-nosed viper (Vipera ammodytes ammodytes). As a member of the M-type sPLA(2) receptors, present on the mammalian plasma membrane, R180 has been proposed to be responsible for one of the first events in the process of presynaptic neurotoxicity, the binding of the toxin to the nerve cell. To test this hypothesis, we prepared and analyzed three N-terminal fusion proteins of AtxA possessing a 12 or 5 amino acid residue peptide. The presence of such an additional "propeptide" prevented interaction of the toxin with the M-type receptor but not its lethality in mouse and neurotoxic effects on a mouse phrenic nerve-hemidiaphragm preparation. In addition, antibodies raised against the sPLA(2)-binding C-type lectin-like domain 5 of the M-type sPLA(2) receptor were unable to abolish the neurotoxic action of AtxA on the neuromuscular preparation. The specific enymatic activities of the fusion AtxAs were two to three orders of magnitude lower from that of the wild type, yet resulting in a similar but less pronounced neurotoxic profile on the neuromuscular junction. This is in accordance with other data showing that a minimal enzymatic activity suffices for presynaptic toxicity of sPLA(2)s to occur. Our results indicate that the interaction of AtxA with the M-type sPLA(2) receptor at the plasma membrane is not essential for presynaptic activity of the toxin. Interaction of AtxA with two intracellular proteins, calmodulin and the R25 receptor, was affected but not prevented by the presence of the N-terminal fusion peptides, implying that these proteins may play a role in the sPLA(2) neurotoxicity.  相似文献   

20.
We investigated the phylogenetic relationships among most Chinese species of lizards in the genus Phrynocephalus (118 individuals collected from 56 populations of 14 well-defined species and several unidentified specimens) using four mitochondrial gene fragments (12S rRNA, 16S rRNA, cytochrome b, and ND4-tRNA(LEU)). The partition-homogeneity tests indicated that the combined dataset was homogeneous, and maximum-parsimony (MP), neighbor-joining (NJ), maximum-likelihood (ML) and Bayesian (BI) analyses were performed on this combined dataset (49 haplotypes including outgroups for 2058bp in total). The maximum-parsimony analysis resulted in 24 equally parsimonious trees, and their strict consensus tree shows that there are two major clades representing the Chinese Phrynocephalus species: the viviparous group (Clade A) and the oviparous group (Clade B). The trees derived from Bayesian, ML, and NJ analyses were topologically identical to the MP analysis except for the position of P. mystaceus. All analyses left the nodes for the oviparous group, the most basal clade within the oviparous group, and P. mystaceus unresolved. The phylogenies further suggest that the monophyly of the viviparous species may have resulted from vicariance, while recent dispersal may have been important in generating the pattern of variation among the oviparous species.  相似文献   

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