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1.
The present generic concept of Phoma is broadly defined, with nine sections being recognised based on morphological characters. Teleomorph states of Phoma have been described in the genera Didymella, Leptosphaeria, Pleospora and Mycosphaerella, indicating that Phoma anamorphs represent a polyphyletic group. In an attempt to delineate generic boundaries, representative strains of the various Phoma sections and allied coelomycetous genera were included for study. Sequence data of the 18S nrDNA (SSU) and the 28S nrDNA (LSU) regions of 18 Phoma strains included were compared with those of representative strains of 39 allied anamorph genera, including Ascochyta, Coniothyrium, Deuterophoma, Microsphaeropsis, Pleurophoma, Pyrenochaeta, and 11 teleomorph genera. The type species of the Phoma sections Phoma, Phyllostictoides, Sclerophomella, Macrospora and Peyronellaea grouped in a subclade in the Pleosporales with the type species of Ascochyta and Microsphaeropsis. The new family Didymellaceae is proposed to accommodate these Phoma sections and related anamorph genera. The present study demonstrated that Phoma radicina, the type species of Phoma sect. Paraphoma and Phoma heteromorphospora, the type species of Phoma sect. Heterospora can be assigned to the Phaeosphaeriaceae and Leptosphaeriaceae respectively.  相似文献   

2.
Molecular phylogenetic evidence indicates that the octocoral family Alcyoniidae is highly polyphyletic, with genera distributed across Octocorallia in more than 10 separate clades. Most alcyoniid taxa belong to the large and poorly resolved Holaxonia–Alcyoniina clade of octocorals, but members of at least four genera of Alcyoniidae fall outside of that group. As a first step towards revision of the family, we describe a new genus, Parasphaerasclera gen. n., and family, Parasphaerascleridae fam. n., of Alcyonacea to accommodate species of Eleutherobia Pütter, 1900 and Alcyonium Linnaeus, 1758 that have digitiform to digitate or lobate growth forms, completely lack sclerites in the polyps, and have radiates or spheroidal sclerites in the colony surface and interior. Parasphaerascleridae fam. n. constitutes a well-supported clade that is phylogenetically distinct from all other octocoral taxa. We also describe a new genus of Alcyoniidae, Sphaerasclera gen. n., for a species of Eleutherobia with a unique capitate growth form. Sphaerasclera gen. n. is a member of the Anthomastus–Corallium clade of octocorals, but is morphologically and genetically distinct from Anthomastus Verrill, 1878 and Paraminabea Williams & Alderslade, 1999, two similar but dimorphic genera of Alcyoniidae that are its sister taxa. In addition, we have re-assigned two species of Eleutherobia that have clavate to capitate growth forms, polyp sclerites arranged to form a collaret and points, and spindles in the colony interior to Alcyonium, a move that is supported by both morphological and molecular phylogenetic evidence.  相似文献   

3.
Tricladium, with 21 accepted species, is the largest genus of aquatic hyphomycetes. It encompasses species with dematiaceous as well as mucedinaceous colonies. Conidiogenesis is thalloblastic; conidiogenous cells proliferate percurrently or sympodially. Conidia have typically two alternate primary lateral branches. Fontanospora and Variocladium are segregates of Tricladium, differing by conidial branching. Varicosporium comprises nine species, one not well known. Conidiogenesis is blastic or thalloblastic, conidiogenous cells proliferate sympodially or are determinate; conidia regularly produce primary and secondary branches and often fragment into part conidia. Molecular analyses on the 28S rDNA of 86 isolates, including 16 species of Tricladium, five species of Varicosporium, two species of Fontanospora and one species of Variocladium, place these hyphomycetes within Helotiales. Tricladium is polyphyletic and placed in six clades; Varicosporium is polyphyletic and placed in three clades; Fontanospora is polyphyletic within a single clade. Variocladium is placed with poor support as a sister taxon to Varicosporium giganteum, Hymenoscyphus scutula and Torrendiella eucalypti.  相似文献   

4.

Background and Aims

Nickel (Ni) hyperaccumulation is a rare form of physiological specialization shared by a small number of angiosperms growing on ultramafic soils. The evolutionary patterns of this feature among European members of tribe Alysseae (Brassicaceae) are investigated using a phylogenetic approach to assess relationships among Ni hyperaccumulators at the genus, species and below-species level.

Methods

Internal transcribed spacer (ITS) sequences were generated for multiple accessions of Alysseae. Phylogenetic trees were obtained for the genera of the tribe and Alyssum sect. Odontarrhena. All accessions and additional herbarium material were tested for Ni hyperaccumulation with the dimethylglyoxime colorimetric method.

Key Results

Molecular data strongly support the poorly known hyperaccumulator endemic Leptoplax (Peltaria) emarginata as sister to hyperaccumulator species of Bornmuellera within Alysseae. This is contrary to current assumptions of affinity between L. emarginata and the non-hyperaccumulator Peltaria in Thlaspideae. The lineage Bornmuellera–Leptoplax is, in turn, sister to the two non-hyperaccumulator Mediterranean endemics Ptilotrichum rupestre and P. cyclocarpum. Low ITS sequence variation was found within the monophyletic Alyssum sect. Odontarrhena and especially in A. murale sensu lato. Nickel hyperaccumulation was not monophyletic in any of three main clades retrieved, each consisting of hyperaccumulators and non-hyperaccumulators of different geographical origin.

Conclusions

Nickel hyperaccumulation in Alysseae has a double origin, but it did not evolve in Thlaspideae. In Bornmuellera–Leptoplax it represents an early synapomorphy inherited from an ancestor shared with the calcicolous, sister clade of Mediterranean Ptilotrichum. In Alyssum sect. Odontarrhena it has multiple origins even within the three European clades recognized. Lack of geographical cohesion suggests that accumulation ability has been lost or gained over the different serpentine areas of south Europe through independent events of microevolutionary adaptation and selection. Genetic continuity and strong phenotypic plasticity in the A. murale complex call for a reduction of the number of Ni hyperaccumulator taxa formally recognized.  相似文献   

5.
6.
In a continued chemosystematic investigation of the water-soluble compounds in Veronica sect. Hebe, we have investigated two more of the species formerly classified as Parahebe. Both species contained mannitol in considerable amounts and in addition some glucosides of iridoid acids. Veronica cheesemanii was characterised by aucubin and its esters: 2′-O-benzoylaucubin and an aucubin diester named cheesemanioside. The main iridoid compounds in Veronica hookeriana were catalpol and its ester verminoside, but this species also contained the sugar ester methyl 1-O-benzoyl-3-α-glucuronosylglycerol and a caffeoyl phenylethanoid glycoside (CPG) named parahebeoside, a 2′-O-β-xylopyranosyl derivative of the known plantamajoside. The results show that the studied species of the former genus Parahebe are very different with regard to their chemical content. This is in agreement with the DNA sequence data and implies the genus was polyphyletic as previously circumscribed.  相似文献   

7.
There are 60 species of blood-feeding land leeches, 50 species belonging to the family Haemadipsidae and 10 species belonging to the family Xerobdellidae. Despite recent papers on the land leeches, their taxonomic identification is not fully understood, especially at a species level. In Korea, there have been no historical records of the terrestrial leeches, but recently an unrecorded blood-feeding land leech was discovered at Gageo-do (Island), Korea. Molecular analysis was used to identify the species of 29 leeches collected from Mt. Dock-Sil in Gageo-do. Conventional PCR was conducted using nuclear 18S rRNA and mitochondrial cytochrome c oxidase subunit 1 (CO1) genetic marker. The 18S rRNA sequences revealed that the leeches share 99.9% identity with Haemadipsa rjukjuana (inhabiting Taiwan), and the CO1 sequences revealed that the leeches are very close to H. rjukjuana (inhabiting Taiwan). The CO1 sequences were separated into 2 categories, 1 with 94.6% and the other with 94.3% similarity to the H. rjukjuana L00115A (inhabiting Taiwan). This new finding of the land leech is the first record in Korea. In addition, the north range of the distribution of the blood-feeding leech (Hirudiniformes: Haemadipisidae) should be reconsidered including Korea.  相似文献   

8.
Members of the Calliphoridae (blowflies) are significant for medical and veterinary management, due to the ability of some species to consume living flesh as larvae, and for forensic investigations due to the ability of others to develop in corpses. Due to the difficulty of accurately identifying larval blowflies to species there is a need for DNA-based diagnostics for this family, however the widely used DNA-barcoding marker, cox1, has been shown to fail for several groups within this family. Additionally, many phylogenetic relationships within the Calliphoridae are still unresolved, particularly deeper level relationships. Sequencing whole mt genomes has been demonstrated both as an effective method for identifying the most informative diagnostic markers and for resolving phylogenetic relationships. Twenty-seven complete, or nearly so, mt genomes were sequenced representing 13 species, seven genera and four calliphorid subfamilies and a member of the related family Tachinidae. PCR and sequencing primers developed for sequencing one calliphorid species could be reused to sequence related species within the same superfamily with success rates ranging from 61% to 100%, demonstrating the speed and efficiency with which an mt genome dataset can be assembled. Comparison of molecular divergences for each of the 13 protein-coding genes and 2 ribosomal RNA genes, at a range of taxonomic scales identified novel targets for developing as diagnostic markers which were 117–200% more variable than the markers which have been used previously in calliphorids. Phylogenetic analysis of whole mt genome sequences resulted in much stronger support for family and subfamily-level relationships. The Calliphoridae are polyphyletic, with the Polleninae more closely related to the Tachinidae, and the Sarcophagidae are the sister group of the remaining calliphorids. Within the Calliphoridae, there was strong support for the monophyly of the Chrysomyinae and Luciliinae and for the sister-grouping of Luciliinae with Calliphorinae. Relationships within Chrysomya were not well resolved. Whole mt genome data, supported the previously demonstrated paraphyly of Lucilia cuprina with respect to L. sericata and allowed us to conclude that it is due to hybrid introgression prior to the last common ancestor of modern sericata populations, rather than due to recent hybridisation, nuclear pseudogenes or incomplete lineage sorting.  相似文献   

9.
Coelomycetous fungi classified in Ascochyta, Phoma, and Phyllosticta have been recorded from spots on leaves and pods of soybeans. Based on the Genealogical Concordance Phylogenetic Species Concept, the authors suggest the re-evaluation of the taxonomic status of Phoma sojicola (syn. = Ascochyta sojicola) and Phyllosticta sojicola. In spite of the former delimitation of Phoma sojicola based on small differences in morphological features, it has proved to be identical to Phoma pinodella. Similarly, it was also confirmed that Phyllosticta sojicola was identical to Phoma exigua var. exigua. The authors supply tools for identification of Phoma-like fungi by combined conventional and molecular methods. Protein-encoding genes (tef1 and β-tubulin) were successfully applied within the Phoma genus to infer phylogenetic relationships.  相似文献   

10.
Melioidosis is an emerging, potentially fatal disease caused by Burkholderia pseudomallei, which requires prolonged antibiotic treatment to prevent disease relapse. However, difficulties in laboratory diagnosis of melioidosis may delay treatment and affect disease outcomes. Isolation of B. pseudomallei from clinical specimens has been improved with the use of selective media. However, even with positive cultures, identification of B. pseudomallei can be difficult in clinical microbiology laboratories, especially in non-endemic areas where clinical suspicion is low. Commercial identification systems may fail to distinguish between B. pseudomallei and closely related species such as Burkholderia thailandensis. Genotypic identification of suspected isolates can be achieved by sequencing of gene targets such as groEL which offer higher discriminative power than 16S rRNA. Specific PCR-based identification of B. pseudomallei has also been developed using B. pseudomallei-specific gene targets such as Type III secretion system and Tat-domain protein. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry, a revolutionary technique for pathogen identification, has been shown to be potentially useful for rapid identification of B. pseudomallei, although existing databases require optimization by adding reference spectra for B. pseudomallei. Despite these advances in bacterial identification, diagnostic problems encountered in culture-negative cases remain largely unresolved. Although various serological tests have been developed, they are generally unstandardized “in house” assays and have low sensitivities and specificities. Although specific PCR assays have been applied to direct clinical and environmental specimens, the sensitivities for diagnosis remain to be evaluated. Metabolomics is an uprising tool for studying infectious diseases and may offer a novel approach for exploring potential diagnostic biomarkers. The metabolomics profiles of B. pseudomallei culture supernatants can be potentially distinguished from those of related bacterial species including B. thailandensis. Further studies using bacterial cultures and direct patient samples are required to evaluate the potential of metabolomics for improving diagnosis of melioidosis.  相似文献   

11.
12.

Background and Aims

Heteromorphy in flowers has a profound effect on breeding patterns within a species, but little is known about how it affects reproductive barriers between species. The heterostylous genus Primula is very diverse in the Himalaya region, but hybrids there have been little researched. This study examines in detail a natural hybrid zone between P. beesiana and P. bulleyana.

Methods

Chloroplast sequencing, AFLP (amplified fragment length polymorphism) markers and morphological comparisons were employed to characterize putative hybrids in the field, using synthetic F1s from hand pollination as controls. Pollinator visits to parent species and hybrids were observed in the field. Hand pollinations were conducted to compare pollen tube growth, seed production and seed viability for crosses involving different morphs, species and directions of crossing.

Key Results

Molecular data revealed all hybrid derivatives examined to be backcrosses of first or later generations towards P. bulleyana: all had the chloroplast DNA (cpDNA) of this species. Some individuals had morphological traits suggesting they were hybrids, but they were genetically similar to P. bulleyana; they might have been advanced generation backcrosses. Viable F1s could not be produced with P. bulleyana pollen on P. beesiana females, irrespective of the flower morphs used. Within-morph crosses for each species had very low (<10 %) seed viability, whereas crosses between pin P. bulleyana (female) and pin P. beesiana had a higher seed viability of 30 %. Thus genetic incompatibility mechanisms back up mechanical barriers to within-morph crosses in each species, but are not the same between the two species. The two species share their main pollinators, and pollinators were observed to fly between P. bulleyana and hybrids, suggesting that pollinator behaviour may not be an important isolating factor.

Conclusions

Hybridization is strongly asymmetric, with P. bulleyana the only possible mother and all detected hybrids being backcrosses in this direction. Partial ecological isolation and inhibition of heterospecific pollen, and possibly complete barriers to F1 formation on P. beesiana, may be enough to make F1 formation very rare in these species. Therefore, with no F1 detected, this hybrid zone may have a finite life span as successive generations become more similar to P. bulleyana.  相似文献   

13.
The internal transcribed spacer (ITS) sequences alignment and proteomic difference of Anoectochilus interspecies have been studied by means of ITS molecular identification and surface enhanced laser desorption ionization time of flight mass spectrography. Results showed that variety certification on Anoectochilus by ITS sequences can not determine species, and there is proteomic difference among Anoectochilus interspecies. Moreover, proteomic finger printings of five Anoectochilus species have been established for identifying species, and genetic relationships of five species within Anoectochilus have been deduced according to proteomic differences among five species.  相似文献   

14.
For most of the family Porcellanidae, which comprises 283 species, larval development remains to be described. Full development has been only described for 52 species, while part of the larval cycle has been described for 45 species. The importance of knowing the complete larval development of a species goes beyond allowing the identification of larval specimens collected in the plankton. Morphological larval data also constitute a support to cladistic techniques used in the establishment of the phylogenetic status (see Hiller et al. 2006, Marco-Herrero et al. 2013). Nevertheless, the literature on the larval development of this family is old and widely dispersed and in many cases it is difficult to collect the available information on a particular taxon. Towards the aim of facilitating future research, all information available on the larval development of porcellanids has been compiled. Following the taxonomic checklist of Porcellanidae proposed by Osawa and McLaughlin (2010), a checklist has been prepared that reflects the current knowledge about larval development of the group including larval stages and the method used to obtain the larvae, together with references. Those species for which the recognised names have been changed according to Osawa and McLaughlin (2010) are indicated.  相似文献   

15.

Background

The aim of our research work was to quantify total flavonoid contents in the leaves of 13 plant species family Asteraceae, 8 representatives of family Lamiaceae and 9 plant species belonging to family Rosaceae, using the multiplex fluorimetric sensor. Fluorescence was measured using optical fluorescence apparatus Multiplex(R) 3 (Force-A, France) for non-destructive flavonoids estimation. The content of total flavonoids was estimated by FLAV index (expressed in relative units), that is deduced from flavonoids UV absorbing properties.

Results

Among observed plant species, the highest amount of total flavonoids has been found in leaves of Helianthus multiflorus (1.65 RU) and Echinops ritro (1.27 RU), Rudbeckia fulgida (1.13 RU) belonging to the family Asteraceae. Lowest flavonoid content has been observed in the leaves of marigold (Calendula officinalis) (0.14 RU) also belonging to family Asteraceae. The highest content of flavonoids among experimental plants of family Rosaceae has been estimated in the leaves of Rosa canina (1.18 RU) and among plant species of family Lamiaceae in the leaves of Coleus blumei (0.90 RU).

Conclusions

This research work was done as pre-screening of flavonoids content in the leaves of plant species belonging to family Asteraceae, Lamiaceae and Rosaceae. Results indicated that statistically significant differences (P > 0.05) in flavonoids content were observed not only between families, but also among individual plant species within one family.  相似文献   

16.

Background and Aims

To address the issues associated with food security, environmental change and bioenergy in the context of crop plants, the production, identification and evaluation of novel plant phenotypes is fundamental. One of the major routes to this end will be wide hybridization and introgression breeding. The transfer of chromosomes and chromosome segments between related species (chromosome engineering or alien introgression) also provides an important resource for determining the genetic control of target traits. However, the realization of the full potential of chromosome engineering has previously been hampered by the inability to identify and characterize interspecific introgressions accurately.

Methods

Seven monosomic substitution lines have been generated comprising Festuca pratensis as the donor species and Lolium perenne as the recipient. Each of the seven lines has a different L. perenne chromosome replaced by the homoeologous F. pratensis chromosome (13 L. perenne + 1 F. pratensis chromosome). Molecular markers and genomic in situ hybridization (GISH) were used to assign the F. pratensis chromosomes introgressed in each of the monosomic substitutions to a specific linkage group. Cytological observations were also carried out on metaphase I of meiosis in each of the substitution lines.

Results

A significant level of synteny was found at the macro-level between L. perenne and F. pratensis. The observations at metaphase I revealed the presence of a low level of interspecific chromosomal translocations between these species.

Discussion

The isolation of the seven monosomic substitution lines provides a resource for dissecting the genetic control of important traits and for gene isolation. Parallels between the L. perenne/F. pratensis system and the Pooideae cereals such as wheat, barley, rye, oats and the model grass Brachypodium distachyon present opportunities for a comparison across the species in terms of genotype and phenotype.  相似文献   

17.
The oribatid mite genus Berndamerus Mahunka, 1977 is transferred into the family Ctenobelbidae as the subgenus Ctenobelba (Berndamerus) Mahunka, 1977, stat. n. from the family Amerobelbidae. The known species of Berndamerus combined: C. (B.) bicostata (Berlese, 1910), comb. n., C. (B.) eremuloides (Berlese, 1910), comb. n., C. (B.) hellenica (Mahunka, 1977), comb. n. A new species, Ctenobelba (Berndamerus) bugiamapensis sp. n., is described from soil, Bu Gia Map National Park, southern Vietnam. It differs from the other species of the subgenus by the heterotrichy of notogastral setae, presence of adanal neotrichy and localization of adanal lyrifissures. Ctenobelbidae is recorded in Vietnam for the first time. A new diagnosis of the family Ctenobelbidae and the identification keys to the known subgenera of the genus Ctenobelba and species of the subgenus Ctenobelba (Berndamerus) are provided.  相似文献   

18.

Background and Aims

Satellite DNA is a genomic component present in virtually all eukaryotic organisms. The turnover of highly repetitive satellite DNA is an important element in genome organization and evolution in plants. Here we assess the presence and physical distribution of the repetitive DNA E180 family in Medicago and allied genera. Our goals were to gain insight into the karyotype evolution of Medicago using satellite DNA markers, and to evaluate the taxonomic and phylogenetic signal of a satellite DNA family in a genus hypothesized to have a complex evolutionary history.

Methods

Seventy accessions from Medicago, Trigonella, Melilotus and Trifolium were analysed by PCR to assess the presence of the repetitive E180 family, and fluorescence in situ hybridization (FISH) was used for physical mapping in somatic chromosomes.

Key Results

The E180 repeat unit was PCR-amplified in 37 of 40 taxa in Medicago, eight of 12 species of Trigonella, six of seven species of Melilotus and in two of 11 Trifolium species. Examination of the mitotic chromosomes revealed that only 13 Medicago and two Trigonella species showed FISH signals using the E180 probe. Stronger hybridization signals were observed in subtelomeric and interstitial loci than in the pericentromeric loci, suggesting this satellite family has a preferential genomic location. Not all 13 Medicago species that showed FISH localization of the E180 repeat were phylogenetically related. However, nine of these species belong to the phylogenetically derived clade including the M. sativa and M. arborea complexes.

Conclusions

The use of the E180 family as a phylogenetic marker in Medicago should be viewed with caution. Its amplification appears to have been produced through recurrent and independent evolutionary episodes in both annual and perennial Medicago species as well as in basal and derived clades.  相似文献   

19.

Background and Aims

The role of flower specialization in plant speciation and evolution remains controversial. In this study the evolution of flower traits restricting access to pollinators was analysed in the bifid toadflaxes (Linaria sect. Versicolores), a monophyletic group of ∼30 species and subspecies with highly specialized corollas.

Methods

A time-calibrated phylogeny based on both nuclear and plastid DNA sequences was obtained using a coalescent-based method, and flower morphology was characterized by means of morphometric analyses. Directional trends in flower shape evolution and trait-dependent diversification rates were jointly analysed using recently developed methods, and morphological shifts were reconstructed along the phylogeny. Pollinator surveys were conducted for a representative sample of species.

Key Results

A restrictive character state (narrow corolla tube) was reconstructed in the most recent common ancestor of Linaria sect. Versicolores. After its early loss in the most species-rich clade, this character state has been convergently reacquired in multiple lineages of this clade in recent times, yet it seems to have exerted a negative influence on diversification rates. Comparative analyses and pollinator surveys suggest that the narrow- and broad-tubed flowers are evolutionary optima representing divergent strategies of pollen placement on nectar-feeding insects.

Conclusions

The results confirm that different forms of floral specialization can lead to dissimilar evolutionary success in terms of diversification. It is additionally suggested that opposing individual-level and species-level selection pressures may have driven the evolution of pollinator-restrictive traits in bifid toadflaxes.  相似文献   

20.
Li QQ  Zhou SD  He XJ  Yu Y  Zhang YC  Wei XQ 《Annals of botany》2010,106(5):709-733

Background and Aims

The genus Allium comprises more than 800 species, placing it among the largest monocotyledonous genera. It is a variable group that is spread widely across the Holarctic region. Previous studies of Allium have been useful in identifying and assessing its evolutionary lineages. However, there are still many gaps in our knowledge of infrageneric taxonomy and evolution of Allium. Further understanding of its phylogeny and biogeography will be achieved only through continued phylogenetic studies, especially of those species endemic to China that have often been excluded from previous analyses. Earlier molecular studies have shown that Chinese Allium is not monophyletic, so the goal of the present study was to infer the phylogeny and biogeography of Allium and to provide a classification of Chinese Allium by placement of Chinese species in the context of the entire phylogeny.

Methods

Phylogenetic studies were based on sequence data of the nuclear ribosomal internal transcribed spacer (ITS) and chloroplast rps16 intron, analysed using parsimony and Bayesian approaches. Biogeographical patterns were conducted using statistical dispersal–vicariance analysis (S-DIVA).

Key Results

Phylogenetic analyses indicate that Allium is monophyletic and consists of three major clades. Optimal reconstructions have favoured the ancestors of Amerallium, Anguinum, Vvedenskya, Porphyroprason and Melanocrommyum as originating in eastern Asia.

Conclusions

Phylogenetic analyses reveal that Allium is monophyletic but that some subgenera are not. The large genetic distances imply that Allium is of ancient origin. Molecular data suggest that its evolution proceeded along three separate evolutionary lines. S-DIVA indicates that the ancestor of Amerallium, Anguinum, Vvedenskya, Porphyroprason and Melanocrommyum originated from eastern Asia and underwent different biogeographical pathways. A taxonomic synopsis of Chinese Allium at sectional level is given, which divides Chinese Allium into 13 subgenera and 34 sections.  相似文献   

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