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1.
Everted cystacanths of Sphaerirostris lanceoides (Petrochenko, 1949) Golvan 1956 are reported from the Asiatic toad Bufo gargarizans Cantor (Amphibia: Anura) for the first time. The prevalence was 1.96% and the intensity ranged between 1.0–3.0 acanthocephalans. SEM observations revealed the morphology of the gonopore and the presence of a flat, bare region on the apical part of the proboscis. Moreover, S. lanceoides was characterised using molecular approaches by sequencing the ribosomal ITS1-5.8S-ITS2 region and the mitochondrial cox1 gene. The resulting ITS sequences were identical and the cox1 sequences showed a divergence of 0–0.75%. Sphaerirostris lanceoides is the first species of the genus for which the ITS1-5.8S-ITS2 and cox1 loci have been sequenced to aid species identification.  相似文献   

2.
3.
The whitebacked planthopper (WBPH), Sogatella furcifera Horvath, is one of the most destructive pests in rice (Oryza sativa L.) production. Host-plant resistance has been considered as an efficient and eco-friendly strategy to reduce yield losses caused by WBPH. In this study, we found that an indica rice cultivar IR54751-2-44-15-24-2 (IR54751) displayed high resistance to WBPH at both seedling and tillering stages. The resistance of IR54751 was mainly contributed by antixenosis and tolerance rather than antibiosis. An F2 population derived from a cross between IR54751 and a susceptible japonica cultivar 02428 was constructed to detect the quantitative trait loci (QTLs) conferring the resistance to WBPH. In total, four QTLs including qWBPH3.1, qWBPH3.2, qWBPH11, and qWBPH12 were identified and distributed on three different chromosomes. The four QTLs had LOD scores of 3.8, 8.2, 5.8, and 3.9, accounting for 8.2, 21.5, 13.9, and 10.4% of the phenotypic variation, respectively. Except for qWBPH3.1, the resistance alleles of the other three QTLs were all from IR54751. Further, a secondary population harboring only single qWBPH11 locus was developed from the F2 population by marker-assisted selection. Finally, qWBPH11 was delimited in a 450-kb region between markers DJ53973 and SNP56. The identification of WBPH resistance QTLs and the fine mapping of qWBPH11 will be helpful for cloning resistance genes and breeding resistant rice cultivars.  相似文献   

4.

Background

Sand rice (Agriophyllum squarrosum (L.) Moq.) is an annual shrub-like plant adapted to the mobile sand dunes in desert and semi-desert regions of Asia. It has a balanced nutrient composition with relatively high concentration of lipids and proteins, which results in its nutrition being similar to legumes. Sand rice’s proteins contain the full range of essential amino acids. However, calories content is more similar to wheat. These features together with desert stress resistance make sand rice a potential food crop resilient to ongoing climate change. It is also an important fodder crop (on young stages of growth) for cattle in arid regions of Kazakhstan. In our work, sand rice samples were collected from two distant regions of Kazakhstan as a part of the nation-wide project to determine genetic variation of the native flora.

Results

Samples were collected in western and southeastern parts of Kazakhstan separated by distances of up to 1300 km. Sequences of the nuclear ribosomal DNA ITS1-5.8S-ITS2 region and the chloroplast matK gene confirmed the identity of species defined by morphological traits. Comparison with GenBank sequences revealed polymorphic sequence positions among Kazakh populations and GenBank references, and suggested a distinction among local populations of sand rice. The phylogenetic analysis of nucleotide sequences showed a clear partition of A. squarrosum (L.) Moq. from Agriophyllum minus Fisch. & C.A. Mey, which grows in the same sand dunes environment.

Conclusions

DNA barcoding analyses of ITS and matK sequences showed a segregation of A. squarrosum from A. minus into separate clades in Maximum-Likelhood dendrograms. ITS analysis can be successfully used to characterize A. squarrosum populations growing quite distant from each other. The data obtained in this work provide the basis for further investigations on A. squarrosum population structure and may play a role in the screening of sand rice plants growing in desert and semi-desert environments of Central Asia and China.
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5.
Region ITS1–5.8S rDNA–ITS2 is sequenced in 27 varieties of cultivated ornamental peonies, ten of which presumably originate from Paeonia lactiflora, one from P. officinalis, 13 from hybridization of P. lactiflora and P. peregrina, or P. officinalis, and three are Itoh hybrids. Comparative analysis of distribution patterns of polymorphic sites (PS) for the obtained DNA sequences and data from GenBank is carried out. Hypotheses of origin of the studied varieties, except for two, which, as previously assumed, originate from hybridization of P. lactiflora and P. peregrina, are confirmed. It is shown that the sequence ITS1–5.8S rDNA–ITS2 is a good genetic marker for cultivars of the P. lactiflora group and Itoh hybrids, and that the PS distribution patterns in these sequences can provide valuable information on the kinship and origin of individual varieties. However, insufficient knowledge of wild species from the P. officinalis kinship group limits the use of this marker in the study of varieties obtained through interspecific hybridization within the Paeonia section.  相似文献   

6.
A fragment of the mitochondrial COI gene from isolates of several echinoderm species was sequenced. The isolates were from three species of starfish from the Asteriidae family (Asterias amurensis and Aphelasterias japonica collected in the Sea of Japan and Asterias rubens collected in the White Sea) and from the sea urchin Echinocardium cordatum (family Loveniidae) collected in the Sea of Japan. Additionally, regions including internal transcribed spacers and 5.8S rRNA (ITS1–5.8S rDNA–ITS2) were sequenced for the three studied starfish species. Phylogenetic analysis of the obtained COI sequences together with earlier determined homologous COI sequences from Ast. forbesii, Ast. rubens, and Echinocardium laevigaster from the North Atlantic and E. cordatum from the Yellow and North Seas (GenBank) placed them into strictly conspecific clusters with high bootstrap support (99% in all cases). Only two exceptions–Ast. rubens DQ077915 sequence placed with the Ast. forbesii cluster and Aph. japonica DQ992560 sequence placed with the Ast. amurensis cluster–were likely results of species misidentification. The intraspecific polymorphism for the COI gene within the Asteriidae family varied within a range of 0.2-0.9% as estimated from the genetic distances. The corresponding intrageneric and intergeneric values were 10.4-12.1 and 21.8-29.8%, respectively. The interspecific divergence for the COI gene in the sea urchin of Echinocardium genus (family Loveniidae) was significantly higher (17.1-17.7%) than in the starfish, while intergeneric divergence (14.6-25.7%) was similar to that in asteroids. The interspecific genetic distances for the nuclear transcribed sequences (ITS1–5.8S rDNA–ITS2) within the Asteriidae family were lower (3.1-4.5%), and the intergeneric distances were significantly higher (32.8-35.0%), compared to the corresponding distances for the COI gene. These results suggest that the investigated molecular-genetic markers could be used for segregation and identification of echinoderm species.  相似文献   

7.
In gastropod mollusk Baicalia carinata Dybowski, 1875, sampled in different sites of the Lake Baikal, comparison of 81 sequences of internal transcribed spacer 1 (ITS1) located between the genes for 18S rRNA and 5.8S rRNA, and of 100 sequences of the fragment of mitochondrial DNA cytochrome-c-oxidase subunit 1 gene (CO1) was performed. Molecular phylogenetic analysis showed that the endemic mollusk species studied formed at least two distinct populations, Southwestern and Eastern. Statistical significance of the species subdivision into two populations was evaluated using the Mann-Whitney rank test.  相似文献   

8.
DNA sequences of Capitotricha bicolor from Quercus, Fagus sylvatica, Alnus alnobetula, and Nothofagus, and C. rubi from Rubus idaeus were obtained from apothecia to establish whether specimens from different hosts belong to separate species. The obtained ITS1–5.8S–ITS2 rDNA sequences were examined with Bayesian and parsimony phylogenetic analyses. Intra- and interspecific variation was also investigated based on molecular distances in the ITS region. The phylogenetic analyses supported the specific distinctness of Capitotricha rubi and the Capitotricha from Nothofagus, but also suggest specific distinctness between samples from Quercus, Fagus, and Alnus. The interspecific distances were larger than intraspecific distances for all examined units. The smallest distance was found between the “Alnus alnobetula” and “Fagus sylvatica” units. Two new sequences of Brunnipila are published. Capitotricha, Lachnum, and Erioscyphella are compared to each other based on hair and excipulum characteristics.  相似文献   

9.
Sequence variability of the ITS spacers and 5.8S rRNA gene was examined in 11 accessions of the subfamily Scilloideae, including seven accessions of rare and endangered species Bellevalia sarmatica from Volgograd region. The intraspecific polymorphism level of the examined ITS1–5.8S–ITS2 sequence of B. sarmatica accessions constituted 1.3%. The phylogenetic position of B. sarmatica within the genus Bellevalia was determined. It was demonstrated that B. sarmatica belonged to the section Nutantes, and the most closely related species were B. webbiana and B. dubia. Nucleotide substitutions in the 5.8S rRNA gene sequence of the analyzed Scilloideae accessions were identified and studied. The predicted secondary structure of 5.8S rRNA gene was constructed. It was demonstrated that in the examined accessions, mutations in the 5.8S rRNA gene were mainly localized in the third hairpin region and had no effect on the secondary structure of the 5.8S rRNA molecule.  相似文献   

10.
Metacercariae of two species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) were subjected to morphological and molecular studies: P. brevicaudatum (von Nordmann, 1832) from Gasterosteus aculeatus (L.) (Gasterosteiformes: Gasterosteidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Perca fluviatilis L. (Perciformes: Percidae), Czech Republic (morphology, cox1, ITS1-5.8S-ITS2 and 28S); and P. centrarchi Hoffman, 1958 from Lepomis gibbosus (L.) (Perciformes: Centrarchidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Slovakia (cox1 and ITS1-5.8S-ITS2). In addition, cercariae of P. cuticola (von Nordmann, 1832) from Planorbis planorbis (L.) (Mollusca: Planorbidae), Lithuania (morphology and cox1) and metacercariae of Ornithodiplostomum scardinii (Schulman in Dubinin, 1952) from Scardinius erythrophthalmus (L.) (Cypriniformes: Cyprinidae), Czech Republic, were examined (morphology, cox1, ITS1-5.8S-ITS2 and 28S). These represent the first molecular data for species of Posthodiplostomum and Ornithodiplostomum Dubois, 1936 from the Palaearctic. Phylogenetic analyses based on cox1 and ITS1-5.8S-ITS2, using O. scardinii as the outgroup and including the three newly-sequenced Posthodiplostomum spp. from Europe and eight published unidentified (presumably species-level) lineages of Posthodiplostomum from Canada confirmed the distinct status of the three European species (contrary to the generally accepted opinion that only P. brevicaudatum and P. cuticola occur in the Palaearctic). The subspecies Posthodiplostomum minimum centrarchi Hoffmann, 1958, originally described from North America, is elevated to the species level as Posthodiplostomum centrarchi Hoffman, 1958. The undescribed “Posthodiplostomum sp. 3” of Locke et al. (2010) from centrarchid fishes in Canada has identical sequences with the European isolates of P. centrarchi and is recognised as belonging to the same species. The latter parasite, occurring in the alien pumpkinseed sunfish Lepomis gibbosus in Europe, is also supposed to be alien for this continent. It is speculated that it colonised Europe long ago and is currently widespread (recorded in Bulgaria, Slovakia and Spain); based on the cox1 sequence of an adult digenean isolate from the Ebro Delta, Spain, only the grey heron (Ardea cinerea L.) (Ciconiiformes: Ardeidae) is known to be its definitive host in Europe.  相似文献   

11.
Mayarhynchus n. g. (Acanthocephala: Neoechinorhynchidae) is erected for Mayarhynchus karlae n. g, n. sp. described from the intestine of four species of cichlid fishes distributed from southeastern Mexico. The new genus placed in the family Neoechinorhynchidae (Ward, 1917) Van Cleave, 1928, is readily distinguished from the other 17 genera in the family by having a small proboscis armed with 45–46 relatively weak rooted hooks arranged in nine longitudinal rows of five hooks each. In addition, Mayarhynchus n. g., n. sp. is diagnosed by the presence of a short trunk, body wall with five dorsal and one ventral giant hypodermal nuclei, proboscis receptacle nearly cylindrical with single layered wall, lemnisci broad and flat with large nuclei, testes in tandem, cement gland with eight large nuclei, and eggs elongate to oval. Partial sequences of the cytochrome c oxidase subunit 1 (cox1), internal transcribed spacers (ITS1 + 5.8S + ITS2), and the D2-D3 domains of the large subunit rRNA gene (28S) were obtained for five specimens of the new species and other species belonging to the Neoechinorhynchidae. Phylogenetic analyses confirmed that the new genus belongs to the Neoechynorhynchidae and indicated that the genus Neoechynorhynchus Stiles & Hassall, 1905 is not monophyletic. Comparison between three populations of the new species yielded nine variable sites for cox1, 11 for ITS and four for 28S.  相似文献   

12.
In the present study, the entire first and second internal transcribed spacer (ITS-1 and ITS-2) regions of nuclear ribosomal DNA (rDNA) of Haemaphysalis longicornis from China were amplified by polymerase chain reaction. The 45 representative amplicons were sequenced, and sequence variation in the ITS was examined. The ITS sequences of H. longicornis were 3644 bp in size, including the part of 18S rDNA, 28S rDNA sequences and the complete ITS-1, 5.8S rDNA and ITS-2 sequences. Sequence analysis revealed that the ITS-1, 5.8S rDNA and ITS-2 of this hard tick were 1582, 152, and 1610 bp in size, respectively. The intra-specific sequence variations of ITS-1 and ITS-2 within H. longicornis were 0–2 and 0–2.2%; however, the inter-specific sequence differences among members of the genus Haemaphysalis were significantly higher, being 35.1–55.2 and 37–52% for ITS-1 and ITS-2, respectively. The molecular approach employed in this study provides the foundation for further studies of the genetic variation of H. longicornis from different hosts and geographical origins in China.  相似文献   

13.
14.
Colletotrichum spp. are causal agents of anthracnose disease in chili fruits and other tropical crops. The disease is increasing in chili fruits in Thailand and significantly reduces fruit quality and fruit production. Forty-eight isolates of Colletotrichum spp. associated with chili anthracnose were collected from different areas of Thailand during 2010–2015. Based on morphological characteristic identification, 10 isolates were shown to belong to the C. gloeosporioides species complex, 24 isolates belong to the C. acutatum species complex and 14 isolates to C. capsici. For molecular identification, two primer sets, ITS1/ITS4 and ACT528/ACT738, were used for amplification of the internal transcribed spacer of rRNA gene (ITS1–5.8S–ITS2) and partial region actin gene (ACT), respectively. The phylogenetic analysis of individual and combined ITS region and actin nucleotide sequences identified the collected isolates into 4 species: C. gloeosporioides, C. siamense, C. acutatum and C. capsici. The pathogenicity test demonstrated that all four species were pathogenic on intact unwounded and healthy fruits. These results indicated that C. capsici, C. acutatum, C. gloeosporioides and C. siamense were the causal agents of chili anthracnose disease.  相似文献   

15.
Structural characteristics and polymorphism of the long (LNR) and short (SNR) mitochondrial noncoding regions were studied in the liver fluke Fasciola hepatica. Flukes were sampled from several populations of Russia and Belarus. LNR amplification yielded a set of nine fragments, neighboring ones differing in length by one tandem repeat (85 bp), published for Australian flukes. The LNR amplification products of different lengths were cloned and sequenced. A comparison of the LNR sequences of Australian and Belarussian flukes revealed three nucleotide substitutions and one point heteroplasmy in the first positions of the imperfect repeat and four adjacent perfect repeats. The positions of the three mutations coincided in the perfect and imperfect repeats. The frequency of mutations was 4.0–4.7 %, while the frequency of heteroplasmic sites varied from 0.1 to 1.2%. It was shown that the mutations and the heteroplasmy of one site could change the structure and stability of the putative secondary structures of the perfect and imperfect repeats. SNR amplification in F. hepatica from several populations yielded fragments that differed from the published SNR sequence of Australian F. hepatica by one transversion (T → G in position 21). Both noncoding regions had several conserved and potential regulatory sequences. The possible causes of heteroplasmy and a concerted origin of substitutions in different repeats are discussed.  相似文献   

16.
The genus Elymus L. is a complicated aggregate of ecological and geographical races, species, subspecies, varieties, and hybrids. We suggest that comparative analysis of intragenomic polymorphism of internal transcribed spacers ITS1 and ITS2 of 35S rRNA genes in the supposed hybrids and their possible “parents” can be one of the approaches to verification of hybrid origin of the samples collected in nature to confirm or reject the hypotheses about their possible “parents.” Polymorphic sites (PS) in ITS of 23 Elymus species, as well as in two supposed interspecific Elymus hybrids and in a supposed intergeneric hybrid between Elymus × Hordeum determined as × Elyhordeum sp., were analyzed in the work. We collected all hybrids in the Altai. There were 2 and 5 PS in two samples of E. dahuricus and 1 and 4 PS in two studied samples of E. schrenkianus in the ITS1-5.8S rDNA-ITS2 region. From 0 to 4 (modes 0 and 3) PS were detected in 32 samples relating to 21 tetraploid Elymus species. More PS (14) were found in the × Elyhordeum sp. sample. A large number of single nucleotide substitutions were found in 5.8S rRNA in × Elyhordeum. It was shown that about half of them do not change the secondary structure of the 5.8S rRNA molecule, so these molecules probably retain the ability to work as a component of large subunit of a ribosome. On the other hand, the absence or weakening of 5.8S rDNA homogenization in × Elyhordeum indirectly suggests that a significant part of 5.8S rDNA is not transcribed. Paradoxically, ITS sequences of × Elyhordeum sp. are less polymorphic than 5.8S rDNA. There are no ITS sequences derived from Hordeum among × Elyhordeum ITS sequenced by Sanger method. No traces of the H subgenome and a subgenome originating from Agropyron (P-subgenome) are seen in the Alt 10–278 plant genome (a chimera, combining the morphological traits of Elymus, Elytrigia, and Agropyron). In this plant, as well as in the supposed intersectional hybrid Alt 11–60 distinguished by a mosaic of the traits typical for the E. caninus × E. mutabilis species, only 4 and 5 PS, respectively, are detected when sequencing by Sanger method. The comparison of ITS sequences of the supposed Elymus Alt 10–278 hybrid and its probable “parents” demonstrates that one of the species of the Elymus macrourus kinship circle, as well as the Elytrigia geniculata, could be one of its ancestors. The comparison of the ITS sequence of the supposed parental species with ITS of Alt 11–60 samples and five PS of the supposed Alt 11–60 hybrid does not contradict the hypothesis that this is an intersectional hybrid of the first generation that emerged with the involvement of E. caninus and E. mutabilis common in the Altai.  相似文献   

17.
Muscodor is a non-sporulating, volatile organic compounds producing endophytic fungi that has been extensively explored as a bio-fumigant and bio-preservative. Novel species of this genus have been mainly identified using ITS sequences. However, the ITS hyper-variability hinders the creation of reproducible alignments and stable phylogenetic trees. Conserved structural data of the ITS region represents as a vital auxiliary information for accurate speciation of fungi. In the present study, secondary structural data of ITS1, 5.8S, and ITS2 region of all Muscodor species were generated using LocaRNA web server. The predicted secondary structural data displayed greater variability in ITS1 region in comparison to ITS2. The structural data of all sequences exhibited characteristic conserved features of eukaryotic rRNA. Evolutionary conserved motifs were found among all 5.8S and ITS2 sequences. Profile neighbor joining (PNJ) tree based on combined sequence-structural information of ITS region was generated in ProfDists. The PNJ tree resolved into four major groups whereby M. fengyangenesis and M. albus species formed monophyletic clades. However, three M. albus species along with other Muscodor species emerged as sister branches to the existing clades, thereby, improving the precision of phylogenetic analysis for identification of novel species of Muscodor genus. Hence, the results indicated that structural analysis along with primary sequence information can provide new insights for precise identification of Muscodor species.  相似文献   

18.
Haemaphysalis qinghaiensis as an endemic species in China mainly infests domestic animals and causes great harm to animals and humans in Northwestern plateau. However, there is no information about genetic diversity within the recently established populations of this tick species. Therefore, the present study analyzed the fragments of mitochondrial 16S rDNA, COI and the nuclear gene ITS1 of 56 H. qinghaiensis ticks across four regions of China which are main endemic areas of this species. Analysis showed 98.1–100% (16S rDNA), 97.9–100% (COI), 99.7–100% (ITS1) identity within individuals. For these sequences, 9, 15 and 8 haplotypes were found for 16S rDNA, COI and ITS1, respectively. Ticks from Yongjing were the most variable group, followed by Lintan, Huangyuan, and Tianzhu. Based on parallel analysis of the mitochondrial and nuclear genetic diversity of H. qinghaiensis, our results indicated that mitochondrial markers (especially COI) were much more useful than nuclear ITS for intraspecific genetic variability analysis.  相似文献   

19.
The Gymnosporia dhofarensis complex (Celastraceae) consists of the closely related taxa G. dhofarensis (Sebsebe) Jordaan and G. parviflora (Vahl) Chiov. and occurs in the fragmented and isolated monsoon-affected refugia of the coastal mountains in a vegetation of relics of (semi-)evergreen Afro-montane woodland and drier habitats (deciduous woodland, open dry scrub) of the southern Arabian Peninsula. To study the phylogeography of the complex, 536 individuals from 31 populations were analysed using cpDNA-RFLP, while a subset of 320 individuals from 20 populations was analysed using AFLP fingerprinting. Additionally, for 46 accessions from populations throughout the distribution range of the complex and 10 individuals of G. senegalensis (Lam.) Exell. s.l. sequences of nrDNA ITS were established to infer ribotype variation and allow dating of diversification events. Phylogeographical reconstructions based on six detected chloroplast haplotypes show a distinct haplotype distribution pattern with a main split between western (Northern Yemen/Jabal Eraf/Jabal Al Aghbar/Jabal Urays; G. parviflora) and eastern populations (Ras Fartak/Hawf Mts/Dhofar Mts; G. dhofarensis). The results of AFLP fingerprinting are congruent with chloroplast data but offer an even more detailed view into the intra-regional population differentiation. The analysis of nrDNA ITS variants shows that G. dhofarensis s.l. is well separated from other Gymnosporia representatives in the study (i.e. G. senegalensis s.l. and G. aff. divaricata). Based on nrDNA ITS sequence variation, the main inter-regional split between western (G. parviflora) and eastern populations (G. dhofarensis) is dated to 0.9–2.2 Ma before present.  相似文献   

20.
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