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Introduction. During a recent explorative field trip to the Western Ghats a new species of Riccia was discovered with possible links to the northern Australian species, Riccia caroliniana Na-Thalang.

Key Results. Morphological similarities between the new species, R. sahyadrica and R. caroliniana include the ventral positioning of the photosynthetic tissue in the ventral section of the thallus in specialised structures known as ventral lamellae. These form a v-shaped patterning along the ventral surface of the thallus and are unique to these two species. Both species also bear similar spores with differences in the micro-ornamentation. Differences between the two species also extend to sexual condition, whereby R. caroliniana is dioicous and R. sahyadrica is monoicous.

Conclusions. A new species, Riccia sahyadrica Manju & Cargill is described and illustrated and compared to the only other morphologically similar species, R. caroliniana endemic to northern Australia. Both species possess the unique characteristic of bearing ventral photosynthetic tissue in contrast to the dorsal position typically seen in all other Riccia species.  相似文献   

3.
Amphibians are declining worldwide.At the same time,each year many species of amphibians are described,indicating that biological diversity on Earth remains poorly understood.This is especially true for mountainous regions,such as the Himalayas,which are also regarded as a biodiversity hotspot.However,it is most likely that the current diversity of amphibians in Nepal is highly underestimated.Amphibian inventories by the past researchers primarily used phenotypic characters as the basis for species identification.However,the application of molecular systematics methods to taxonomic studies has successfully uncovered the taxonomic status of several cryptic taxa.This study used both molecular(16 S rDNA sequences)and morphological comparisons and estimated the diversity of amphibians from Nepal.This study reports the occurrence of 38 species of amphibians based on both molecular and morphological comparisons.Among them,three species were recorded for the first time in Nepal.This study also invalids the taxonomic status of Sphaerotheca paschima.This study highlights the importa nce of integrative taxonomic approaches that help to resolve the current taxonomic ambiguities of Nepalese amphibians.  相似文献   

4.
通过电镜扫描方法 ,研究了 3个属 9种的中国叶状体苔类植物 :稀枝钱苔 (RicciahuebenerianaLindb .)、宽翅钱苔 (R .hantamensisPerold .)、曲脊钱苔 (R .cavernosaHoffm .)、R .warnstorfiiLimpr.exWarnst.、小孢钱苔 (R .frostiiAust.)、中华钱苔 (R .chinensisHerz .)、东亚花萼苔 (Asterellayoshinagana (Horik .)Horik .)、矮网花萼苔 (A .sanguiniaL .etL .)、背托苔 (Preissiaquadrata) (Scop .)Nees.)。对上述种类的孢子形态特征进行了描述。研究发现 ,上述 3属的孢子形态特征具有明显差异。而且同一属的孢子形态特征也存在差异 ,甚至可以作为种类划分的依据之一。同时采自不同地点的同一种类其孢子形态有时具微小的差别。这可能是由于生态环境差异所造成的  相似文献   

5.
We sequenced a part of the mitochondrial cytochrome-b gene from the seven treecreeper species, including 18 subspecies, to reconstruct the phylogeny of the genus Certhia . Species status of all seven species could be affirmed. Certhia discolor , C. himalayana , C . nipalensis , and C . tianquanensis , the species with relatively small distribution ranges in southeast Asia and simple territorial song, are found at the base of all phylogenetic trees, although without good support. A comparatively recent sister species of C. tianquanensis is C. nipalensis , replacing C. discolor as closest relative. Certhia familiaris , C. brachydactyla and C. americana form a derived set of species (again only weak support). The closest relative of C. americana is C. brachydactyla . The C. familiaris subtree is deeply split into two well-defined population groups: a Eurasian group including populations in northern China (Qinling range northward and all Eurasia) and a Sino-Himalayan group (Himalayas and China excluding northern China). In accordance with acoustic characters, the three subspecies hodgsoni , mandellii and khamensis of the Sino-Himalayan group are combined and elevated to species rank: Certhia hodgsoni . Certhia discolor manipurensis is deeply split from nominate discolor as well, and is also promoted to species level. Within C. brachydactyla (western palearctic) and within C. hodgsoni (Himalayas, China) several populations form well-supported separate lineages that diverged quite recently and represent subspecies level. In all other species, molecular–genetic and vocal characters support traditional species delimitation.  相似文献   

6.
We used morphological and genetic data to assess the taxonomic status of Rana amurensis coreana and R. a. amurensis. Morphological comparisons revealed these two subspecies to be different from each other in size of body, nature of tubercles on dorsal stripe, degree of development in toe webbing, and condition of lateral spots of trunk. They were also different in sequence of mitochondrial 16S rRNA gene, with genetic distance as large as those observed among different species of brown frogs. Therefore, Korean populations previously considered a subspecies of R. amurensis should be regarded as a distinct species (=R. coreana).  相似文献   

7.
《Journal of bryology》2013,35(3):367-377
Abstract

Two new Riccia species, R. somaliensis and R. erubescens from Africa are described and illustrated. They are both classified in the subgenus Riccia, section Riccia. R. somaliensis has hyaline, somewhat frilly scales and apolar, wingless spores; R. erubescens has shiny dark, purple-red to bright cherry-red scales and polar, winged spores with numerous small areolae; its tissues are sometimes distorted by gelatinous globules that are gradually extruded on the dorsal surface.  相似文献   

8.
We used morphological, vocal and molecular (one mitochondrial and two nuclear loci) data to re-evaluate the taxonomic status of the taxa acanthizoides , concolor , and brunnescens in the Cettia acanthizoides (J. Verreaux, 1871) complex. We conclude that all three are valid taxa, and that acanthizoides of China and concolor of Taiwan are best treated as conspecific, whereas brunnescens of the Himalayas is better considered as a separate species. The degree of morphological, vocal, and genetic differentiation is variably congruent among all taxa; the recently separated acanthizoides and concolor differ slightly in plumage and structure but are indistinguishable in vocalizations, whereas the earlier diverged brunnescens and acanthizoides/concolor differ only slightly more in morphology but to a much greater degree in vocalizations. We stress the essential nature of taxonomic revisions as a prerequisite for the biodiversity estimates required for conservation planning.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 437–452.  相似文献   

9.
Wu, H.‐C., Lin, R.‐C., Hung, H.‐Y., Yeh, C.‐F., Chu, J.‐H., Yang, X.‐J., Yao, C.‐J., Zou, F.‐S., Yao, C.‐T., Li, S.‐H. & Lei, F.‐M. (2011). Molecular and morphological evidences reveal a cryptic species in the Vinaceous Rosefinch Carpodacus vinaceus (Fringillidae; Aves). —Zoologica Scripta, 40, 468–478. The Vinaceous Rosefinch (Carpodacus vinaceus) is endemic in East Asia with two recognized subspecies –C. v. vinaceus, distributed along the eastern edge of the Tibetan Plateau and the Himalayas, and C. v. formosanus, restricted to Taiwan’s Central Mountain Range. As reflected in a controversial taxonomic history, this vastly disjunctive distribution pattern suggests that the subspecies, having been isolated from each other for a long time, might have diverged, challenging the current taxonomic treatment and calling for possible species delimitation. Sequences of two mitochondrial fragments (mtDNA) and two Z‐linked nuclear loci (zDNA) were used to reconstruct the intraspecific phylogeny of C. vinaceous. The mtDNA tree shows that the two subspecies of the vinaceous rosefinch form two exclusively monophyletic clades. All but one zDNA sequences from the nominate subspecies and C. v. formosanus also formed exclusively monophyletic clades (the exceptional zDNA sequence from C. v. vinaceous formed a weakly supported clade with two outgroup species). Moreover, by conducting quantitative comparisons of morphometric traits and male plumage coloration, we found that the two subspecies exhibit distinguishable morphological differences. All the evidence therefore suggests that C. v. formosanus is a cryptic species and that its taxonomic status should be restored to full species. Molecular dating suggests that the two sibling rosefinches split 1.7 ± 0.2 million years ago, providing a point estimate for the historical connectivity of biota between eastern Tibet‐Himalayas and montane Taiwan.  相似文献   

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11.
A morpho-molecular study was undertaken to solve the taxonomic identity of Riccia plants from the Canary Islands. These plants were assumed to belong to the South African endemic Riccia section Pilifer, but could not be assigned to a particular species in that section. In the interim they were named R. lamellosa (section Riccia), since R. lamellosa is the only European species with conspicuous white ventral scales. Molecular phylogenetic reconstructions based on trnL-F and ITS2 sequences confirmed that the respective Riccia plants belong to section Pilifer. The respective clade is clearly separated from the clades of R. lamellosa and R. elongata, the latter being morphologically most similar within section Pilifer. Based on the combined molecular and morphological evidence the Riccia plants from Canary Islands are described as a new species, R. boumanii, which represents the first species of section Pilifer outside South Africa. Based on revised herbarium specimens, R. boumanii occurs on five islands of the Canary Islands archipelago, namely El Hierro, Gran Canaria, La Gomera, La Palma, and Tenerife.  相似文献   

12.
We have analysed samples from Sweden, Denmark, and Germany of six facultatively apomictic blackberry species to investigate the accordance between a taxonomy based on morphological characters on the one hand, and distribution of genetic variation estimated by DNA fingerprinting on the other hand. DNA fingerprint variation was found to be quite restricted in all species investigated. The first taxonomic group included three species related toRubus nessensis, two being characterized by one very widespread DNA fingerprint in all three countries and a few rare ones, whereas the third species differed between Sweden and Germany. The second taxonomic group included species related toR. gracilis. Two of these species exhibited very similar DNA fingerprints, whereas the third species deviated clearly. The utilization of DNA fingerprinting as a tool in taxonomy is discussed; most likely this method could become a useful complement to morphology, especially in plant groups with reduced levels of genetic recombination.  相似文献   

13.
唇形突是海链藻中常见的一类突起, 其形态学特征和排列方式是重要的分类学依据。绝大多数海链藻只有一个唇形突, 两个唇形突的现象仅报道于极少数海链藻种类。我国关于双唇形突海链藻的报道较少。研究利用扫描电镜(SEM)技术, 对采自我国沿海海域的自然水样, 以及分离获得的单克隆培养藻株进行了形态学观察, 针对其中的海链藻属Thalassiosira Cleve种类开展了形态学的专题研究。报道了4个具有双唇形突的海链藻种类, 分别是有翼海链藻T. bipartita (Rattray) Hallegraeff、脆弱海链藻T. fragilis Fryxell、亨氏海链藻T. hendeyi Hasle &; Fryxell和维斯吉思海链藻T. visurgis Hustedt, 其中有3个为我国新记录种类: 脆弱海链藻、亨氏海链藻和维斯吉思海链藻。对每个种类的形态学特征、生活习性和生态分布进行了描述, 提供了扫描电镜照片, 对相似种类的形态学特征进行了比较研究, 分析了唇形突的变化类型及其分类学价值。  相似文献   

14.
? Premise of the study: Hybridization is common in both animals and plants and can lead to a diverse array of outcomes ranging from the generation of new ecotypes or species to the breakdown of morphological differences. Here, we explore the extent of hybridization in the three currently recognized New World Rhizophora species-R. mangle, R. racemosa, and the putative hybrid species R. harrisonii. ? Methods: We assayed variation across the three recognized Rhizophora species using two noncoding chloroplast (cpDNA), two flanking microsatellite regions (FMRs), and six microsatellite loci. ? Key results: Gene genealogies of cpDNA and FMRs showed a strong phylogeographic break across the Central American Isthmus, but little relationship to recognized species boundaries. Instead, individuals collected in the same ocean basin and classified as R. mangle and R. racemosa by morphological characteristics were more closely related to each other than with similar looking individuals collected in the other ocean basin. Nonetheless, there were low, yet significant differences at microsatellite loci among co-occurring populations of R. mangle and R. racemosa in both ocean basins, suggesting that two taxonomic groups coexist. However, we found no genetic evidence that R. harrisonii was a hybrid species. Rather, R. harrisonii appears to represent a morphotype produced by ongoing hybridization and backcrossing between R. mangle and R. racemosa. ? Conclusions: Our data support ancient and persistent introgressive hybridization among new world Rhizophora and argue for a full revision of the systematic relationships of the group based on much finer morphological, ecological, and genetic analyses.  相似文献   

15.
Integration of molecular genetic techniques and geometric morphometrics represent a valuable tool in the resolution of taxonomic uncertainty and the identification of significant units for conservation. We combined mitochondrial DNA cytochrome c oxidase subunit II gene sequence data and geometric morphometric analysis to examine taxonomic status and identify units for conservation in four species of the hypogean beetle Duvalius (Coleoptera, Trechinae) using mainly museum specimens collected in central Italy. Previous taxonomic studies based on morphological traits described several subspecies often inhabiting geographically distinct caves. Phylogenetic analysis identified two well supported monophyletic lineages and a number of different clades with relatively small genetic differences, suggesting a short divergence time in line with known geological history of the study area. Geometric morphometrics, on the other hand, recovered a high level of distinctiveness among specimens. Both genetic and morphometric analyses did not entirely corroborate former taxonomic nomenclature, suggesting possible rearrangements and the definition of evolutionary significant units. Beetles of the genus Duvalius are protected by regional laws and the majority of taxa considered in this study inhabit caves located outside protected areas. Our study advocates the importance of devoting protection efforts to networks of cave ecosystems rather than single locations or species.  相似文献   

16.
《Journal of bryology》2013,35(2):154-157
Abstract

We revised both the holotype and an isotype of Riccia teneriffae S.W.Arnell 1962 and additionally revised our own collections of Riccia cavernosa Hoffm. 1795 from the Canary Islands. Since the types of R. teneriffae represent R. cavernosa, and the latter name precedes the former, R. teneriffae should be treated as a synonym of R. cavernosa. In the Canary Islands, R. cavernosa appears to be rare. It has been found on La Gomera, Gran Canaria, Lanzarote, and Tenerife. We report it as new to Fuerteventura. R. cavernosa inhabits ephemeral, thin layers of mud. Very rarely it occurs on basaltic pyroclasts. SEM images of spores are presented. The local distribution is mapped.  相似文献   

17.
Riccia fruticulosa O.F.Müll., 1782 from Norway is a valid name, referring to Riccardia palmata (Hedw.) Carruth. In 1785 Dickson misidentified British plants of a blue Metzgeria as R. fruticulosa . The European blue species of Metzgeria is conspecific with M. violacea (Ach.) Dumort., which replaces M. fruticulosa auct. The true origin of the type of Jungermannia violacea Ach., 1805 is probably Tierra del Fuego (rather than Dusky Bay, New Zealand), where the species is widespread. Reports from Australasia, Asia and Africa are all erroneous. The blue colour of Jungermanniales is found only in living plants and is derived from the oil-bodies. In contrast, that of Metzgeria appears only after death; its biological function is unknown.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 142 , 229−235.  相似文献   

18.
L Lu  D Chesters  W Zhang  G Li  Y Ma  H Ma  X Song  H Wu  F Meng  C Zhu  Q Liu 《PloS one》2012,7(8):e43479
Although mammals are a well-studied group of animals, making accurate field identification of small mammals is still complex because of morphological variation across developmental stages, color variation of pelages, and often damaged osteological and dental characteristics. In 2008, small mammals were collected for an epidemiological study of a spotted fever outbreak in Hainan, China. Ten species of small mammals were identified by morphological characters in the field, most using pelage color characters only. The study is extended here, in order to assess whether DNA barcoding would be suitable as an identification tool in these small mammals. Barcode clusters showed some incongruence with morphospecies, especially for some species of Rattus and Niviventer, so molecular delineation was carried out with an expanded dataset of combined cytochrome b (Cyt-b) and cytochrome c oxidase subunit I (COI) sequences. COI sequences were successfully amplified from 83% of collected mammals, but failed in all specimens of Suncus murinus, which were thus excluded in DNA barcoding analysis. Of note, ten molecular taxonomic units were found from samples of nine morphologically identified species. Accordingly, 11 species of small mammals were present in the investigated areas, including four Rattus species, three Niviventer species, Callosciurus erythraeus, Neohylomys hainanensis, Tupaia belangeri, and Suncus murinus. Based on the results of the phylogenetic and molecular delineation analyses, the systematic status of some rodent species should be redefined. R. rattus hainanicus and R. rattus sladeni are synonyms of R. andamanensis. R. losea from China and Southeast Asia comprises two independent species: R. losea and R. sakeratensis. Finally, the taxonomic status of three putative species of Niviventer should be further confirmed according to morphological, molecular and ecological characters.  相似文献   

19.
The meadow spittlebugs Philaenus spumarius and P. tesselatus are closely related taxa with uncertain taxonomic position in the light of previous morphological, ecological, cytological and molecular research. Despite morphological homogeneity of P. spumarius (with the exception of high colour and pattern polymorphism) across its wide Holarctic range, it is possible that additional taxa (species or subspecies) exist. Philaenus spumarius is a potentially important pest in parts of its range where it was introduced. We used DNA markers to describe the genetic diversity of P. spumarius and P. tesselatus and to verify the taxonomic status of P. tesselatus and remote populations of the former species. The mitochondrial (cytochrome B) data showed that there are two main groups encompassing a northeastern (Asia and north‐central Europe) and a southwestern (Mediterranean area and western Europe, including North American specimens) clade. According to the elongation factor‐1α gene, there are three main clades: northeastern (Eurasiatic clade, E1), southeastern (east Mediterranean – Caucasus clade, E2) and southwestern (Iberian clade, E3). These two or three mitochondrial and nuclear clades could be considered as separate taxonomic units. On the other hand, all studied individuals of both species possessed the same internal transcribed spacer 2 haplotype. American specimens most probably originated from some western European populations. All studied specimens of P. tesselatus belong to the southwestern clade and western Mediterranean cluster. Therefore, together with cytological data, its species status is doubtful. To definitively solve the taxonomic status of P. tesselatus and populations of P. spumarius, further research using more samples and more genetic markers are needed.  相似文献   

20.
The response of photosynthetic rate to pH indicates that CO2 is the inorganic carbon (Ci) species preferentially used by the liverwort Riccia fluitans for photosynthesis. The absence of external carbonic anhydrase (CA) activity and insensitivity to the anion-exchanger inhibitor 4,4-diisothiocyanostilbene-2,2-disulphonate (DIDS) suggest that bicarbonate is not taken up. Cultivation with bicarbonate produces a decrease in the semi-saturation constant for Ci and an increase in soluble CA activity, but maximum photosynthetic rate decreases and no significant change in the Ci compensation point occurs. Plants cultivated at 1% CO2 show no significant differences in photosynthetic characteristics and CA activity from control plants. Electrophysiological measurements also suggest that CO2 is the form that crosses the plasmalemma. Application of 1% CO2 results in a transient hyperpolarization of the membrane potential (Em) and also a transient acidification of the cytoplasmic pH (pHc). Addition of 1 mM bicarbonate at pH 7.3 produces a similar but less marked response; at an external pH of 8.3 no acidification is observed. These results suggest that bicarbonate is not transported, because its effect mimics the response caused by CO2 which enters the cell inducing a fall in cell pH, and a hyperpolarization of Em probably due to stimulation of the proton pump.Key words: Riccia fluitans, inorganic carbon, membrane potential, cytoplasmic pH, photosynthesis.   相似文献   

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