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1.
The genus Penicillium is one of the largest and widely distributed fungal genera described to date. As a result, its taxonomic classification and species discrimination within this genus has become complicated. In this study, 52 isolates that belonged to the Penicillum genus and other related genera were characterized using two DNA-based methods: (i) analysis of the nucleotide sequences of internal transcribed spacers in ribosomal DNA and (ii) analysis of DNA fingerprints that were generated by polymerase chain reactions with specific primers for enterobacterial repetitive intergenic consensus (ERIC) and repetitive extragenic palindromic (REP) sequences, and BOX elements. Using both methods, Penicillium species were discriminated from other fungal genera. Furthermore, Penicillium species that include strains which are used as biocontrol agents, such as P. glabrum, P. purpurogenum, and P. oxalicum, could be distinguished from other Penicillium species using these techniques. Based on our findings, we propose that a polyphasic approach that includes analysis of the nucleotide sequences of ribosomal DNA and detecting the presence of highly conserved, repeated nucleotide sequences can be used to determine the genetic relationships between different Penicillium species. Furthermore, we propose that our results can be used as a start point to develop a strategy to monitor the environmental presence of particular strains of Penicillium species when they are used as biocontrol agents.  相似文献   

2.
Genomic DNA was extracted from 13 samples of Sargassum polycystum and S. siliquosum collected from various localities around Peninsular Malaysia and Singapore by using four different extraction methods. The yields and the suitability of the DNA to be used as template for the polymerase chain reaction (PCR) was compared. DNA samples were subjected to PCR analysis by using random primers. Only DNA samples that were extracted using the CTAB method were successfully amplified by random amplified polymorphic DNA (RAPD)-PCR. Five of 31 random primers (OPA02, OPA03, OPA04, OPA13 and OPM10) tested amplified sequences of DNA from the DNA samples. Reproducible, amplified products were obtained using these primers and showed some potential to be useful in discriminating individual samples within the genus, in determining relationships between species within a genus and in developing individual fingerprints for individual samples.  相似文献   

3.
We used a mitochondrial and nuclear DNA phylogeny to evaluate the relationships among all noddies (Anous and Procelsterna, Laridae) and to clarify their classification. The Lesser Noddy Anous tenuirostris and Black Noddy Anous minutus form a pair of closely related sister‐species, as do the Blue Noddy Procelsterna albivitta and Grey Noddy Procelsterna cerulea. Blue and Grey Noddies are embedded within the dark noddies and are the sister‐clade to the Lesser and Black Noddies, indicating that the genus Anous in its current definition is not monophyletic. Thus, we propose to merge all noddies into the genus Anous Stephens 1826 , and to consider Procelsterna Lafresnaye 1842 as a junior synonym.  相似文献   

4.
Understanding the taxonomiy of the tropical genus Clusia (Fam. Clusiaceae, Ord. Theales) has been hampered by the difficulties inherent in studying tropical dioecious, succulent, arborescent, epi- or hemiepiphytic taxa. Species identification by morphological traits often requires the terminal inflorescences and/or the succulent capsular fruits. To allow species differentiation based exclusively on vegetative tissue, a frequent necessity during ecological field studies, a procedure has been developed for rapid isolation of genomic DNA from Clusia leaf tissue followed by DNA amplification fingerprinting with a set of single arbitrary oligomer primers (23–27 mers). Fingerprints obtained with independent DNA preparations from one individual as well as DNA preparations from several individuals of the same species were identical for the major amplification products, although minor bands were somewhat variable. Polymorphic fingerprints have been obtained with 3 different primers for 3 Clusia species (C. minor L., C. alata Pl. & Tr., C. multiflora H. B. K.), and the related Oedematopus obovatus Spruce ex. PL (Clusiaceae). The interspecific Randomly Amplified Polymorphic Markers (RAPDs) thus obtained allow a rapid identification of vegetative tissue samples collected in the field, and will assist in a revision of the controversial taxonomy of the genus Clusia.  相似文献   

5.
Species delimitation is difficult for taxa in which the morphological characters are poorly known because of the rarity of adult morphs or sexes, and in cryptic species. In primitively segmented spiders, family Liphistiidae, males are often unknown, and female genital morphology – usually species‐specific in spiders – exhibits considerable intraspecific variation. Here, we report on an integrative taxonomic study of the liphistiid genus Ganthela Xu & Kuntner, 2015, endemic to south‐east China, where males are only available for two of the seven morphological species (two known and five undescribed). We obtained DNA barcodes (cytochrome c oxidase subunit I gene, COI) for 51 newly collected specimens of six morphological species and analysed them using five species‐delimitation methods: DNA barcoding gap, species delimitation plugin [P ID(Liberal)], automatic barcode gap discovery (ABGD), generalized mixed Yule‐coalescent model (GMYC), and statistical parsimony (SP). Whereas the first three agreed with the morphology, GMYC and SP indicate several additional species. We used the consensus results to delimit and diagnose six Ganthela species, which in addition to the type species Ganthela yundingensis Xu, 2015, completes the revision of the genus. Although multi‐locus phylogenetic approaches may be needed for complex taxonomic delimitations, our results indicate that even single‐locus analyses based on the COI barcodes, if integrated with morphological and geographical data, may provide sufficiently reliable species delimitation. © 2015 The Linnean Society of London  相似文献   

6.
Integrative taxonomy is considered a reliable taxonomic approach of closely related and cryptic species by integrating different sources of taxonomic data (genetic, ecological, and morphological characters). In order to infer the boundaries of seven species of the evacanthine leafhopper genus Bundera Distant, 1908 (Hemiptera: Cicadellidae), an integrated analysis based on morphology, mitochondrial DNA, and hyperspectral reflectance profiling (37 spectral bands from 411–870 nm) was conducted. Despite their morphological similarities, the genetic distances of the cytochrome c oxidase subunit I (COI) gene among the tested species are relatively large (5.8–17.3%). The species‐specific divergence of five morphologically similar species (Bundera pellucida and Bundera spp. 1–4) was revealed in mitochondrial DNA data and reflectance profiling. A key to identifying males is provided, and their morphological characters are described. Average reflectance profiles from the dorsal side of specimens were classified based on linear discriminant analysis. Cross‐validation of reflectance‐based classification revealed that the seven species could be distinguished with 91.3% classification accuracy. This study verified the feasibility of using hyperspectral imaging data in insect classification, and our work provides a good example of using integrative taxonomy in studies of closely related and cryptic species. © 2015 The Linnean Society of London  相似文献   

7.
The genus Xanthomonas is characterized by its phytopathogenic diversity and the host specificity of its members. In the past, the classification of the members of this genus has been based primarily on the criterion of host specificity. This has led to a classification system which focused only on naming phytopathogenic variants on different hosts. Extensive taxonomic examination of Xanthomonas has shown that the phytopathogenic specialization of the bacteria is not correlated with the actual relationships within the genus. Based upon total genomic DNA homology, the genus has been reclassified into 20 species. At present, non-pathogenic xanthomonads are frequently isolated from plant material. As these strains often cannot be classified to existing species, it becomes clear that the diversity of the genus is much greater than expected from the phytopathogenic subpopulation, which has been the primary subject in the past. The example of Xanthomonas also illustrates that attempts to divide bacterial populations into discrete taxa conflict with the actual continuous nature of biodiversity. Received 16 April 1996/ Accepted in revised form 27 September 1996  相似文献   

8.
RAPD (Random Amplified Polymorphic DNA) fingerprints have recently been used to estimate genetic and taxonomic relationships in plants. In this study RAPD analysis was performed on 32 clones belonging to different species of the genus Populus. Of these, 25 clones are registered in several countries for commercial use and, altogether, cover almost 50% of the worlds cultivated poplars. DNA was prepared from leaves and amplified by PCR using random oligonucleotide primers. Amplification products were separated by agarose-gel electrophoresis to reveal band polymorphisms. Four primers out of the 18 tested, were selected on the basis of the number and frequency of the polymorphisms produced. With these a total of 120 different DNA bands were reproducibly obtained, 92% of which were polymorphic. The polymorphisms were scored and used in band-sharing analyses to identify genetic relationships. With a few but interesting exceptions, these are consistent with the present taxonomy of the genus Populus and with the known predigrees of cultivated poplars. Moreover, the results show that RAPD analysis allows one to discriminate among all tested clones and can, therefore, be recommended as a convenient tool to defend plant breeders rights.  相似文献   

9.
Species concept and delimitation are fundamental to taxonomic and evolutionary studies. Both inadequate informative sites in the molecular data and limited taxon sampling have often led to poor phylogenetic resolution and incorrect species delineation. Recently, the whole chloroplast genome sequences from extensive herbarium specimen samples have been shown to be effective to amend the problem. Stachyuraceae are a small family consisting of only one genus Stachyurus of six to 16 species. However, species delimitation in Stachyurus has been highly controversial because of few and generally unstable morphological characters used for classification. In this study, we sampled 69 individuals of seven species (each with at least three individuals) covering the entire taxonomic diversity, geographic range, and morphological variation of Stachyurus from herbarium specimens for genome‐wide plastid gene sequencing to address species delineation in the genus. We obtained high‐quality DNAs from specimens using a recently developed DNA reconstruction technique. We first assembled four whole chloroplast genome sequences. Based on the chloroplast genome and one nuclear ribosomal DNA sequence of Stachyurus, we designed primers for multiplex polymerase chain reaction and high throughput sequencing of 44 plastid loci for species of Stachyurus. Data of these chloroplast DNA and nuclear ribosomal DNA internal transcribed spacer sequences were used for phylogenetic analyses. The phylogenetic results showed that the Japanese species Stachyurus praecox Siebold & Zucc. was sister to the rest in mainland China, which indicated a typical Sino‐Japanese distribution pattern. Based on diagnostic morphological characters, distinct distributional range, and monophyly of each clade, we redefined seven species for Stachyurus following an integrative species concept, and revised the taxonomy of the family based on previous reports and specimens, in particular the type specimens. Furthermore, our divergence time estimation results suggested that Stachyuraceae split from its sister group Crossosomataceae from the New World at ca. 54.29 Mya, but extant species of Stachyuraceae started their diversification only recently at ca. 6.85 Mya. Diversification time of Stachyurus in mainland China was estimated to be ca. 4.45 Mya. This research has provided an example of using the herbarium specimen‐based phylogenomic approach in resolving species boundaries in a taxonomically difficult genus.  相似文献   

10.
The ant Cataglyphis cursor is exceptional in that unmated workers are potentially able to lay both male and female eggs. We characterized eight pairs of primers for microsatellite loci, developed from genomic DNA for this species. Variability was tested with DNA from 19 workers and all eight loci were highly polymorphic, displaying 5–10 alleles and a high level of heterozygosity. Cross‐species amplifications indicate that these microsatellites might be useful in genetic studies of other species belonging to the genus Cataglyphis.  相似文献   

11.
Like other plant sap‐sucking insects, planthoppers within the family Cixiidae (Insecta: Hemiptera: Fulgoromorpha) host a diversified microbiota. We report the identification and first molecular characterization of symbiotic bacteria in cixiid planthoppers (tribe: Pentastirini). Using universal eubacterial primers we first screened the eubacterial 16S rRNA sequences in Pentastiridius leporinus (Linnaeus) with PCR amplification, cloning, and restriction fragment analysis. We identified three main 16S rRNA sequences that corresponded to a Wolbachia bacterium, a plant pathogenic bacterium, and a novel gammaproteobacterial symbiont. A fourth bacterial species affiliated with ‘Candidatus Sulcia muelleri’ was detected in PCR assays using primers specific for the Bacteroidetes. Within females of two selected cixiid planthoppers, P. leporinus and Oliarus filicicola, fluorescence In situ hybridization analysis and transmission electron microscopy observations showed that ‘Ca. Sulcia muelleri’ and the novel gammaproteobacterial symbiont were housed in separate bacteriomes. Phylogenetic analysis revealed that both of these symbionts occurred in at least four insect genera within the tribe Pentastirini. ‘Candidatus Purcelliella pentastirinorum’ was proposed as the novel gammaproteobacterial symbiont.  相似文献   

12.
The molecular methods currently used in the classification and identification of bifidobacteria are reviewed. The sequencing of the 16S rRNA gene and some other genes considered to be phylogenetic markers is a universal and effective approach for taxonomic characterization of members of the genus Bifidobacterium and to reliable identification of new isolates. Various techniques of obtaining DNA fingerprints (PFGE, RAPD, rep-PCR) are widely used for solving particular problems in identifying bifidobacteria. Bacteria of the genus Bifidobacterium are important organisms in biotechnology and medicine. The research in the field of molecular systematics of bifidobacteria provides a basis not only for the solution of taxonomic problems, but also for monitoring of individual species in the environment and for more detailed study of the genetics and ecology of this group of microorganisms.  相似文献   

13.
An extended molecular phylogenetic analysis of Uvaria (Annonaceae) is presented, using maximum parsimony, maximum likelihood and Bayesian methods, based on sequences of four plastid DNA regions (matK, psbA‐trnH spacer, rbcL and trnL‐F). The additional taxa include the monotypic West African genus Balonga, the monotypic South‐East Asian genus Dasoclema and seven Australian representatives of the genus Melodorum. The results indicate that all of these taxa are nested within a well‐supported clade otherwise consisting of Uvaria species, indicating that their taxonomic treatment needs to be reassessed. The distinguishing morphological characteristics of the taxa are re‐evaluated and interpreted as specialized adaptations of the basic Uvaria structure. The genus Uvaria is accordingly extended following the transfer of these species, necessitating six new nomenclatural combinations and two replacement names. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163 , 33–43.  相似文献   

14.
The phylogeny of the genus Rivellia Robineau‐Desvoidy was inferred from mitochondrial 16S ribosomal (r)DNA gene sequences of 13 Korean Rivellia species and six species representing other platystomatid genera and the family Tephritidae. We compared the inferred molecular phylogeny with the previously published morphological cladogram. As a result, the following phylogenetic relationships were recognized: (i) monophyly of the genus Rivellia; (ii) monophyly of the R. syngenesiae species group; (iii) R. depicta and R. apicalis (which were not previously placed in any species group) were recognized as a sister group of the R. syngenesiae species group; and (iv) monophyly of the R. basilaris species group was recognized to a limited extent. These results, even though geographically limited, provide a new insight into the phylogeny of the genus Rivellia. They clearly show the utility of 16S rDNA for phylogenetic analysis of the genus Rivellia. Additional study involving samples from different geographical areas will be needed to gain a better understanding of the adaptive radiation of this species‐rich genus.  相似文献   

15.
Polymerase chain reaction (PCR) amplification of total DNA was evaluated as a method to distinguish Xanthomonas campestris pv. pelargonii from other pathovars within this species. Two sets of highly conserved enterobacterial consensus sequences were used as targets for PCR amplification: (a) enterobacterial repetitive intergenic consensus [ERIC] and (b) repetitive extragenic palindromic [REP] sequences. Nucleic acid was extracted from a total of 37 isolates of bacteria: 19 isolates ofX campestris pv. pelargonii and 18 isolates representing 10 other pathovars of X. campestris. After PCR amplification using the ERIC primer pair the DNA fingerprints of X. campestris pv, pelargonii contained two major DNA products (estimated size 500 and 740 pp) that were conserved among all 19 isolates. With the REP primer pair, the fingerprints were more complex and major DNA products ranging from -690 to 1650 bp were detected. Using information from both ERIC- and REP-primed Imgerprints, the X. campestris pv. pelargonii fingerprints were distinguishable from the fingerprints of the other pathovars examined: pvs. citrumelo. citri, beganiae, vittans B and C. phaseoli. campestris, manihotis, juglandis, carotae and pruni.  相似文献   

16.
Here, I show that prey sequences can be detected from DNA of tiger beetles of the genus Rivacindela using whole specimens, nondestructive methods, and universal cytochrome b primers for arthropods. BLAST searches of the obtained sequences against public databases revealed that the diet of Rivacindela is mostly composed of flies but also termites and other beetles. Accurate determination of order, family and even genus was achieved in most cases but rarely to species level. Results suggest that stored DNA samples extracted from whole predatory specimens could be an alternative to dissected gut contents as starting source for DNA‐based dietary studies.  相似文献   

17.
In this study, we used sequences of two mitochondrial genes, cytochrome c oxidase I (COI) and 16S rRNA, and one nuclear gene, 28S rRNA, to test the monophyly of the sea star genus Echinaster, and understand the phylogenetic relationships among species and subgenera within this genus. Phylogenetic analyses based on Bayesian inference and maximum likelihood methods revealed three clades with high values of genetic divergence among them (K2P distances for COI over 23%). One of the clades grouped all Echinaster (Othilia) species, and the other two clades included Echinaster (non‐Othilia) species and Henricia species, respectively. Although the relationships among Henricia, Othilia, and Echinaster could not be completely clarified, the Othilia clade was a well‐supported group with shared diagnostic morphological characters. Moreover, the approximately unbiased test applied to the phylogenetic reconstruction rejected the hypothesis of the genus Echinaster as a monophyletic group. According to these results, we suggest the revalidation of Othilia as a genus instead of a subgenus within Echinaster. Our study clarifies important points about the phylogenetic relationships among species of Echinaster. Other important systematic questions about the taxonomic classification of Echinaster and Henricia still remain open, but this molecular study provides bases for future research on the topic.  相似文献   

18.
Species diagnosis is of the utmost importance to both pest management and plant quarantine services. Because of difficulties in the morphological diagnosis of spider mites, molecular techniques are of great value to rapidly and accurately diagnose closely related species. We examined four species of genus Tetranychus (the green and red forms of T. urticae, and T. kanzawai, T. phaselus and T. truncatus), which are found in Korea and are of significance to plant quarantine services. DNA samples isolated from a single egg, larva or adult weighed 64–188 ng. We designed species‐specific primers by performing sequence alignment for 107 sequences of the ribosomal internal transcribed spacer 2 (ITS2) region, which we obtained from GenBank, and sequences generated in this study. Specific nucleotides of each species were selected for designing primers specific for each species. Each species‐specific primer pair, when used to perform PCR analyses, detected only the species from which it originated. However, a T. urticae‐specific primer pair did not discriminate between the green and red forms of this species. These species‐specific primers can be applied in practice for the rapid and accurate diagnosis of spider mite species in plant quarantine and in agricultural fields.  相似文献   

19.
Although universal or consensus chloroplast primers are available, they are limited by their number and genomic distribution. Therefore, a set of consensus chloroplast primer pairs for simple sequence repeats (ccSSRs) analysis was constructed from tobacco (Nicotiana tabacum L.) chloroplast sequences. These were then tested for their general utility in the genetic analysis of a diverse array of plant taxa. In order to increase the number of ccSSRs beyond that previously reported, the target sequences for SSR motifs was set at A or T (n 7) mononucleotide repeats. Each SSR sequence motif, along with ±200-bp flanking sequences from the first of each mononucleotide base repeat, was screened for homologies with chloroplast DNA sequences of other plant species in GenBank databases using BLAST search procedures. Twenty three putative marker loci that possessed conserved flanking sequence spans were selected for consensus primer pair construction using commercially available computer algorithms. All primer pairs produced amplicons after PCR employing genomic DNA from members of the Cucurbitaceae (six species) and Solanaceae (four species). Sixteen, 22 and 19 of the initial 23 primer pairs were successively amplified by PCR using template DNA from species of the Apiaceae (two species), Brassicaceae (one species) and Fabaceae (two species), respectively. Twenty of 23 primer pairs were also functional in three monocot species of the Liliaceae [onion (Allium cepa L.) and garlic (Allium sativum L.)], and the Poaceae [oat (Avena sativa L.)]. Sequence analysis of selected ccSSR fragments suggests that ccSSR length and sequence variation could be useful as a tool for investigating the genetic relationships within a genus or closely related taxa (i.e., tribal level). In order to provide for a marker system having significant coverage of the cucumber chloroplast genome, ccSSR primers were strategically "recombined" and named recombined consensus chloroplast primers (RCCP) for PCR analysis. Successful amplification after extended-length PCR of 16 RCCP primer pairs from cucumber (Cucumis sativus L.) DNA suggested that the amplicons detected are representative of the cucumber chloroplast genome. These RCCP pairs, therefore, could be useful as an initial molecular tool for investigation of traits related to a chloroplast gene(s) in cucumber, and other closely related species.Communicated by C. Möllers  相似文献   

20.
The genus Peganum (Zygophyllaceae) consists of six species and one subspecies; three of which are distributed in China, P. harmala Linn, P. nigellastrum Bunge and P. multisectum (Maxim.) Bobr. A probable new or intermediate species, Peganum sp., has been suggested in the wild in northwest China. Traditional classification in genus Peganum has focused on hairs on the plant surface. In this study, seed coat characteristics of Peganum species were investigated using light and scanning electron microscopy, demonstrating clear differences in morphology between species. In addition, DNA sequence data from two sequences (chloroplast: trnL‐F, psbA‐trnH) were used to differentiate Peganum sp. and study polygenetic relationships. Diversity in DNA sequences among Peganum species was found, with inter‐specific sequence divergence ranging from 0.6% to 5.6% in psbA‐trnH, and 0.0% to 1.8% in trnL‐F. The variations within species were low: from 0.0% to 0.4% in psbA‐trnH and 0.0% to 0.4% in trnL‐F. Therefore, Peganum species can now be easily identified as separate entities based on variations in DNA sequences. Phylogenetic trees were constructed from the combined data set for the two gene fragments, and the results indicate that Peganum sp. is monophyletic and sister to P. harmala and P. nigellastrum, while P. multisectum is also monophyletic. DNA data further confirmed that P. multisectum is an independent species and that a new species, Peganum sp., exists within the genus Peganum growing wild in China.  相似文献   

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