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1.
Quantitatively evaluated C-banding karyograms and further observations on karyotype structure are presented for Scilla persica, 7 species of the Scilla hohenackeri group, and Puschkinia scilloides. Within the S. hohenackeri group very diverse and species-specific banding patterns are found. On the basis of karyology, S. bisotunensis and S. furseorum should be closely grouped together, while S. persica and Puschkinia scilloides appear quite isolated. 相似文献
2.
A new species, Cymopterus davisii, from alpine areas in the Albion Mountains of extreme south-central Idaho, is described. It has been confused with C. nivalis, with which it is compared. The fruit of C. davisii are subterete to somewhat compressed laterally and, contrary to the literature, correspond closely to those of C. nivalis and related species. 相似文献
4.
Helichrysum Mill. (Asteraceae) species have been used in folk medicine for thousands of years in the world. The in vitro cytogenetic
effects in human lymphocytes of nine Helichrysum taxa used in Turkey folk medicine were investigated. Blood samples were obtained from healthy donors, non-smoking volunteers,
which were incubated and exposed to increasing concentrations of methanol extracts of Helichrysum taxa (0.01, 0.05, 0.1, 0.5 and 1 mg/mL). The inhibitory effects of H. stoechas (L.) Moench subsp. barrelieri (Ten.) Nyman, H. armenium DC. subsp. armenium, H. armenium DC. subsp. araxinum (Kirp.) Takht., H. plicatum DC. subsp. plicatum, H. compactum Boiss. and H. artvinense P.H.Davis & Kupicha on the mitotic index and replication index indicate that these taxa can have genotoxic and mutagenic
effects. They should therefore not be used freely in alternative medicine although their antiproliferative activity may suggest
anticarcinogenic properties. Increase effects of H. stoechas subsp. barrelieri, H. armenium subsp. armenium, H. armenium subsp. araxinum, H. chasmolycicum P.H.Davis, H. plicatum subsp. plicatum, H. compactum and H. artvinense on the micronucleus rates showed that these taxa can have genotoxic and carcinogenic effects. 相似文献
5.
Two scombropid fishes, Scombrops boops and Scombrops gilberti, are closely related and commercially important species in Japan. These species are often confused in commercial markets because of their morphological similarity. In this study, scombropid specimens collected from various Japanese coastal waters were subjected to polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analysis and phylogenetic analysis of the 16S rRNA gene in mitochondrial DNA. These analyses showed that all the scombropid specimens collected from localities in the Sea of Japan were identified as S. boops, whereas those from the Pacific Ocean included two species, S. boops and S. gilberti. Almost all juvenile (<200 mm standard body length, SL) S. gilberti originated from the Pacific coastal waters of the northern Japan, whereas adults (>400 mm SL) were found only in deep water off the Izu Peninsula to the Izu Islands. This suggests that S. gilberti might migrate extensively during its life cycle. In addition, differences in the number of specimens and the distribution between the two species suggest that S. gilberti is less abundant than S. boops in Japanese waters. 相似文献
6.
Analyses of mitochondrial DNA and morphological variation were performed on specimens of all five currently recognised Syngnathus pipefish species from the eastern Pacific Ocean with type localities currently considered to lie within the Californian marine biogeographic province: kelp pipefish Syngnathus californiensis, bay pipefish S. leptorhynchus, barred pipefish S. auliscus, barcheek pipefish S. exilis and chocolate pipefish S. euchrous. Results consistently differentiate S. auliscus from the other species and fail to distinguish all other specimens as distinct species, as indicated by extensive morphological overlap as well as incomplete lineage sorting and considerably low genetic divergence for 16s and coI genes(<1%). This study presents a taxonomic revision of eastern Pacific Syngnathus spp. and proposes the synonymy of S. leptorhynchus, S. euchrous and S. exilis, under the senior synonym, S. californiensis. There is still a need to study populations of Syngnathus spp. from north and south of the Californian province to assess whether these too are synonyms of the two-species recognised here. 相似文献
7.
Veronica davisii M. A. Fischer, sp. n., limited to the mountains of Kurdistan (S. E. Turkey and N. Iraq), is related to the Turkish-Caucasian V. gentianoides
Vahl.— V. montbretii M. A. Fischer, sp. n., a local endemic of Erzincan prov. (E. Anatolia), shows affinities to the Caucasian V. liwanensis
C. Koch and to the Turkish endemic V. oltensis
Woron. & Schelk. from Erzurum province. 相似文献
10.
We supply information about hosts and distribution of Amblyomma dubitatum. In addition, we carry out an analysis of genetic divergence among specimens of A. dubitatum from different localities and with respect to other Neotropical Amblyomma species, using sequences of 16S rDNA gene. Although specimens of A. dubitatum were collected on several mammal species as cattle horse, Tapirus terrestris, Mazama gouazoubira, Tayassu pecari, Sus scrofa, Cerdocyon thous, Myocastor coypus, Allouata caraya, Glossophaga soricina and man, most records of immature and adult stages of A. dubitatum were made on Hydrochoerus hydrochaeris, making this rodent the principal host for all parasitic stages of this ticks. Cricetidae rodents ( Lundomys molitor, Scapteromys tumidus), opossums ( Didelphis albiventris) and vizcacha ( Lagostomus maximus) also were recorded as hosts for immature stages. All findings of A. dubitatum correspond to localities of Argentina, Brazil, Paraguay and Uruguay, and they were concentrated in the Biogeographical provinces
of Pampa, Chaco, Cerrado, Brazilian Atlantic Forest, Parana Forest and Araucaria angustifolia Forest. The distribution of A. dubitatum is narrower than that of its principal host, therefore environmental variables rather than hosts determine the distributional
ranges of this tick. The intraspecific genetic divergence among 16S rDNA sequences of A. dubitatum ticks collected in different localities from Argentina, Brazil and Uruguay was in all cases lower than 0.8%, whereas the
differences with the remaining Amblyomma species included in the analysis were always bigger than 6.8%. Thus, the taxonomic status of A. dubitatum along its distribution appears to be certain at the specific level. 相似文献
11.
The large-clawed scorpion, Scorpio maurus, is a medically important scorpion and yet nothing is known regarding genetic diversity within this species. As a preliminary
analysis we determined variation within the cytochrome oxidase 1 (CO1) mitochondrial gene from specimens from Morocco. High
levels of genetic diversity were found that presented some geographical coherence. Of the two identified subspecies from Morocco,
S. maurus birulai and S. maurus fuliginosus, the latter included genetically distinct lineages (8.0% uncorrected sequence divergence), indicating a detailed morphological
and molecular revision is needed for this species. 相似文献
12.
Spondias L. comprises at least nine Neotropical species, including the widely cultivated S. monbim and S. tuberosa. Umbu‐cajá, a putative hybrid between these two species, is also grown. In this paper, the karyotypes of five Spondias species and Umbu‐cajá were analysed for evidence of this hybridization. Chromosome banding with chromomycin A 3 and the distribution of 5S and 45S rDNA sites were used to characterize the plants, also genomic in situ hybridization using nuclear DNA from both putative parents and the hybrid as probes. All material presented the same chromosome number (2 n = 32) and morphology, but differed in the number and distribution of bands. Spondias monbim and S. tuberosa, the supposed relatives of Umbu‐cajá, displayed similar banding patterns, with five to six chromosome pairs having terminal bands, whereas Umbu‐cajá exhibited bands on both members of nine chromosome pairs. The three other species, S. venulosa, S. cytherea and S. purpurea, showed less closely related karyotypes, with bands in 12–18 chromosome pairs. In situ hybridization with 5S and 45S rDNA probes revealed one site of each probe per haploid chromosome complement in all material. However, in S. tuberosa, the location of 5S rDNA was different from the other species and found no counterpart in Umbu‐cajá. Several tests with total DNA from S. mombin and S. tuberosa against metaphase chromosomes of Umbu‐cajá failed to differentiate the individual genomes in the hybrid. From the chromosome banding and the distribution of rDNA sites, as well as from the genomic in situ hybridization, it seems clear that Umbu‐cajá is related closely to S. monbim and S. tuberosa, but it is karyotypically homozygous and distinct from theses other species. Karyotypically, the three other investigated species were related less closely to Umbu‐cajá. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155 , 541–547. 相似文献
13.
Synopsis
Scaphirhynchus albus and S. platorynchus were studied in Missouri during 1978–1979 to assess their distribution and abundance, to obtain information on their life
histories, and to identify existing or potential threats to their survival. S. platorynchus was collected in substantial numbers (4355 specimens) at all 12 sampling stations in the Missouri and Mississippi rivers,
while only 11 S. albus were captured from 6 stations. Twelve specimens identified in the field as hybrids between the two species were captured
from 4 stations. Morphometric and meristic comparisons of presumed hybrids with the parent species, using cluster and principal
components analyses, demonstrated intermediacy of most specimens identified in the field as hybrids. Aquatic insects comprised
most of the diet of S. platorynchus and S. albus, but S. albus and the hybrids had consumed considerable quantities of fish. S. albus grew more rapidly than S. platorynchus, while the growth of hybrids was intermediate. Hybridization appears to be a recent phenomenon, resulting from man-caused
changes in the big-river environment. Hybridization may be a threat to survival of S. albus in the study streams. 相似文献
14.
Dual color fluorescence in situ hybridization (FISH) was performed to study the simultaneous chromosomal localization of 18S
and 5S ribosomal genes in the genus Tor for the first time. The 18S and 5S rDNAs in four Tor species were amplified, sequenced and mapped on the metaphase chromosomes. The number and distribution of 18S and 5S rDNA
clusters were examined on metaphase chromosome spreads using FISH. The specimens of T. chelynoides, T. putitora and T. progeneius showed six bright fluorescent signals of 18S rDNA and T. tor exhibited ten such signals. The 5S rDNA signals were present only on one pair of chromosomes in all the four Tor species. Ag-NORs were observed on two pairs of chromosomes in T. chelynoides, T.
putitora, T. progeneius and four pairs in T. tor. Comparison of the observed 18S rDNA FISH signals and Ag-NORs strongly suggested a possible inactivation of NORs localized
at the telomeres of a subtelocentric and telocentric chromosome pairs in all four species. The 5S rDNA contained an identical
120 bp long coding region and 81 bp long highly divergent non-transcribed spacers in all species examined. 18S and 5S rDNA
sequencing and chromosomal localization can be a useful genetic marker in species identification as well as phylogenetic and
evolutionary studies. 相似文献
16.
Sphagnum magellanicum has been viewed as being a predominantly circumpolar species in the northern hemisphere, but it occurs in the southern hemisphere and was originally described from the southern parts of Chile. It is an ecologically important species in mire ecosystems and has been extensively used as a model to study processes of growth, carbon sequestration and peat decomposition. Molecular and experimental studies have, however, revealed genetic structure within S. magellanicum, and morphological differences associated with these genetic groups. Here we describe Sphagnum divinum in Sphagnum subgenus Sphagnum (Sphagnaceae, Bryophyta) as a new species, based on molecular and morphological evidence. Sphagnum medium is reinstated as a distinct species and is epitypified. Consequently, a new species concept of S. magellanicum is presented including an epitypification. Important morphological characters to separate these three species in the field and under the microscope are presented. Ecology and distribution differ among the species; S. divinium has a wide habitat range including mire margin, forested peatlands and moist heaths, and a circumpolar distribution around the northern hemisphere. Sphagnum medium seems to be more restricted to ombrotrophic mire expanse habitats and shows an amphi-Atlantic distribution in the northern hemisphere. Sphagnum magellanicum has a very broad ecological niche in peatlands and is found in most mire habitats in Tierra del Fuego on the southern tip of South America. 相似文献
17.
Plesiochorus Looss, 1901 is a genus of Gorgoderidae infecting the urinary bladders of marine turtles globally. Currently, just two morphologically similar species are recognised, Plesiochorus cymbiformis (Rudolphi, 1819) Looss, 1901 and Plesiochorus elongatus Pigulevsky, 1953, which have been distinguished by molecular data and subtle morphological differences. Here we describe a new species, Plesiochorus irwinorum n. sp., infecting hawksbill turtles (Eretmochelys imbricata (L.)), which is primarily distinguished from the other two species of Plesiochorus on the basis of ITS2, cox1 and 28S sequence data. Morphometric data for specimens examined during this study overlap between P. cymbiformis and P. irwinorum n. sp. for every measured feature, rendering them functionally cryptic. However, principal components analysis clearly distinguishes the two species. Additionally, we report new specimens of P. cymbiformis, and provide new sequence data for specimens from Australian loggerhead (Caretta caretta (L.)) and hawksbill turtles. There is little understanding of the host-specificity or geographical distribution of the three species of Plesiochorus, and it remains possible that some of the previously reported sequences have been attributed to the wrong species. 相似文献
18.
The Portuguese dogfish Centroscymnus coelolepis is a wide-ranging deep-water shark and a common by-catch component of the catches of several mid- to deep-water fisheries. In the present study, two new records from the south-western Atlantic Ocean are reported based on specimens caught by bottom-longline fishing vessels operating in the Argentinean–Uruguayan Common Fishing Zone. Species identification based on morphology and detailed morphometrics, as well as molecular data are presented for one of the specimens. The distribution of the species over the south-western Atlantic is discussed on the basis of the available bibliography and a thorough revision of museum collections. The records presented here expand the species' previously acknowledged distribution southwards, from around 21° S to at least 38° S, suggesting it occurs continuously along the shelf break of eastern South America. However, given the limited access to specimens of deep-water sharks in the region, the abundance and real extent of C. coelolepis distribution in the south-western Atlantic as well as its interaction with deep-water fisheries remain to be fully assessed. 相似文献
19.
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
20.
The allozymes and morphology of 110 specimens of three Sebastiscus species ( S. marmoratus, S. tertius, and S. albofasciatus) in the East China Sea and near Japan were compared. Results of 20 allozyme loci studied showed that all three species were
closely related (Nei's unbiased genetic distances, 0.057–0.133) but could be identified on the basis of informative loci with
a few exceptions. Initial identification based on color patterns agreed with allozyme identification in more than 98% of Sebastiscus specimens and agreed completely in S. albofasciatus. One specimen that was initially identified as S. marmoratus because of the dark body color was actually S. tertius according to two informative allozyme loci. Number of pectoral fin rays differed between S. marmoratus (18 or fewer, 98%) and S. tertius (19 or more, 85%) in this study. The previously mentioned dark specimen had 19 pectoral fin rays, which are characteristic
in S. tertius. Using seven morphological measurements, canonical discriminant analysis between S. marmoratus and S. tertius classified less than 90% of specimens into the original groups (species). Some specimens of S. tertius resembled S. marmoratus in body shape and vice versa. A combination of genetic characterization and morphological examination is necessary to identify
S. marmoratus and S. tertius accurately. Distinction based on allozymes and color patterns with numbers of pectoral fin rays should provide satisfactory
identification.
Received: May 16, 2000 / Revised: December 19, 2000 / Accepted: January 24, 2001 相似文献
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