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1.
The genus Crinum L. is the only pantropical genus of the Amaryllidaceae. Phylogenetic and biogeographical analyses of nrDNA ITS and plastid trnL-F sequences for all continental groups of the genus Crinum and related African genera are presented, with the genus Amaryllis used as outgroup. ITS indicates that C. baumii is more closely related to Ammocharis and Cybistetes than to Crinum sensu stricto . Three clades are resolved in Crinum s.s. One unites a monophyletic American group with tropical and North African species. The second includes all southern African species and the Australian endemic C. flaccidum . The third includes monophyletic Madagascar, Australasian and Sino-Himalayan clades, with southern African species. The trnL-F phylogeny resolves an American and an Asian/Madagscar clade, and confirms the relationship of C. flaccidum with species endemic to southern Africa. The salverform, actinomorphic perianths of subg. Crinum appear to have evolved several times in the genus from ancestors with zygomorphic perianths (subg. Codonocrinum ), thus neither subgenus is monophyletic. Biogeographical analyses place the origin of Crinum in southern Africa, as the region is optimized at all ancestral nodes in the tree topology, and in basal interior nodes of all but one of the major clades. The genus underwent three major waves of radiation corresponding to the three main clades resolved in our trees. Two entries into Australia for the genus are indicated, as are separate Sino-Himalayan and Australasian dispersal events.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 349–363.  相似文献   

2.
African and Iberian populations of the genus Cobitis exhibit high morphological polymorphism and their taxonomy is unclear. In seven such populations the percentage of polymorphic loci ranged between _ P =0.08–0.48 and mean heterozygosity per locus H =0.005–0.073. The lowest Nei genetic distance between African and Iberian populations of Cobitis was D =0.250. The populations separated with the formation of the Gibraltar strait 5 million years ago. C. calderoni is a well-differentiated branch from the rest of the Iberian populations of the genus. Our analysis supports the concept that C. paludica populations and C. maroccana are referable to the subgenus Iberocobitis . These African and Iberian populations represent two taxa, C. maroccana Pellegrin, 1929 and C. paludica De Buen, 1930. C. maroccana and C. paludica populations are monophyletic and the African population is the most differentiated genetically. The Arrago population of C. paludica is genetically the most differentiated of the Iberian populations. Our allozyme data do not support the previous consideration of the Albufera lagoon population as a different species from C. paludica .  相似文献   

3.
The study of gill and skin parasites of three fishes species belonging to the genus Clarias: C. camerunensis, C. jaensis and C. pachynema, from the Nyong basin (Cameroon), revealed the presence of two new Monogenean species of the genus Gyrodactylus Nordmann: G. camerunensis n. sp. and G. nyongensis n. sp. parasite of Clarias camerunensis, C. jaensis and C. pachynema. Gyrodactylus camerunensis n. sp. is clearly distinguished from G. nyongensis n. sp. by the smaller size of the haptor sclerites. These two new species differ also from their closest African relatives of the genus Gyrodactylus, G. rysavyi, G. clarii and G. alberti, by the morphology and size of the haptorail sclerites. Their host specificity was discussed and appeared stenoxenous (mesostenoxenous).  相似文献   

4.
国产白酒草亚族(菊科紫菀族)由白酒草属(Conyza)、小舌菊属(Microglossa)和歧伞菊属(Thespis)3个小属组成,且国产白酒草亚族各属间及其与非洲白酒草属植物之间的分子系统发育关系尚无报道,故本研究利用核糖体DNA ITS和ETS序列并采用最大简约法和贝叶斯分析法,重建了国产白酒草亚族的分子系统发育树。结果表明,国产4种白酒草属植物、歧伞菊和非洲白酒草属植物组成一支,而劲直白酒草的两变种和小舌菊嵌入田基黄亚族分支;小舌菊与Psiadia pascalii近缘。基于这些结果,我们认为:(1)劲直白酒草和Conyza incisa应处理为田基黄亚族的一个独立的属;(2)国产4种白酒草属植物和歧伞菊以及大多数非洲白酒草属植物属于Eschenbachia属,而且Eschenbachia属代表一个新的亚族,歧伞菊可处理为Eschenbachia属的一个组。Eschenbachia属可能从非洲经数次长距离传播到达我国南部;(3)Welwitschiella 和小舌菊属应保持属的地位,Psiadia pascalii、Conyza scabrida和C. pyrrhopappa可并入小舌菊属。  相似文献   

5.
We examined 2 cichlid fish species native to México, Cichlasoma callolepis and C. fenestratum, and 2 introduced African cichlids, Oreochromis aureus and O. niloticus, from 3 localities in southeastern México for monogeneans. Six monogenean species infected the African cichlids: Cichlidogyrus haplochromii, C. dossoui, C. longicornis longicornis, C. sclerosus, C. tilapiae, and Enterogyrus malmbergi. We found all these parasite species, except C. haplochromii and C. dossoui, on the native C. fenestratum and C. callolepis. Prevalences of Cichlidogyrus spp. were 3-10% and abundances ranged from 0.03 +/- 0.2 to 0.1 +/- 0.3 for native cichlids. We only recovered a single E. malmbergi from 1 C. callolepis. We found Sciadicleithrum bravohollisae, a monogenean of native Cichlasoma spp., on the gills of the introduced O. aureus from Lake Catemaco (prevalence 3%, abundance 0.03 +/- 0.2). Although prevalence and abundance in atypical hosts were fairly low, the present findings provide evidence of monogenean transfer from African to American cichlids and vice versa. This is the first record of exotic monogeneans in the genus Cichlidogyrus and Enterogyrus infecting native American cichlid fish. It is also the first record from southeastern México of a native American monogenean infecting introduced African cichlids.  相似文献   

6.
Relationships of the newly discovered dwarf crocodiles from Mauritania were inferred from mitochondrial 12S sequences. Specimens from 13 different Crocodylus niloticus populations (from East Africa, West Africa and Madagascar) were compared. Additional representatives of the genus Crocodylus (one from Africa and one from Australia), the African genus Osteolaemus and the South American alligatorid Paleosuchus palpebrosus (as outgroup) were included in the analysis. Maximum-likelihood and Bayesian analyses yielded relationships that were strikingly different from currently prevailing phylogenetic hypotheses. Both analyses consistently revealed two groups, one consisting of the monophyletic West- and Central African populations and the other of a paraphyletic group containing the East African and Madagascan populations. High genetic divergence between those groups indicates separation on the species level. Furthermore ‘Ccataphractus is clearly shown not to be a member of the genus Crocodylus. The resulting nomenclatural changes are discussed. To cite this article: A. Schmitz et al., C. R. Palevol 2 (2003).  相似文献   

7.
A review of the Oriental genus Cochinchinula Volk. (Coleoptera, Buprestidae, Polycestinae, Acmaeoderini) comprising three species is presented. The new species C. thailandica and C. bilyi spp. n. and the new genus Thaichinula gen. n. (type species T. ohmomoi sp. n.) from Thailand are described. A key to species of the genera Cochinchinula and Thaichinula is provided. The Nearctic genus Paracmaeoderoides Bellamy and Westcott is transferred from the subtribe Nothomorphina to the subtribe Acmaeoderoidina, and the South African genus Richtersveldia Bellamy is transferred from the subtribe Nothomorphina of Acmaeoderini to the tribe Ptosimini. The generic status is restored for another South African genus, Brachmaeodera Volkovitsh and Bellamy. The main evolutionary trends are discussed, and the taxonomic composition and classification of the tribe Acmaeoderini are clarified.  相似文献   

8.
Four new species of oribatid mites of the genus Crotonia , ( C. pauropelor sp. nov., C. dicella sp. nov., C. lyrata sp. nov. and C. ecphylla sp. nov. ) are described from soil and plant litter from South Africa. Crotonia pauropelor, C. dicella and C. ecphylla are allied to the 'capistrata' species-group, previously known only from Queensland, Australia, in that they possess the full complement of c setae on the notogaster. They differ in having eight pairs rather than nine pairs of genital setae. In addition, C. ecpylla is unusual in the genus Crotonia in that it appears to possess two pairs of setae on each of the second epimera. Crotonia lyrata has only two pairs of c setae and is allied to the 'cophinaria' species-group. This is only the second published record of the genus Crotonia from South Africa, and the first of any named species. A key to the African Crotonia species is provided, which includes the only two previously known species C. alluaudi and C. rothschildi (Berlese, 1916).  相似文献   

9.
LUCEÑO, M. & CASTROVIEJO, S., 1993. Cytotaxonomic studies in the sections Spirostachyae (Dreyer) Bailey and Ceratocystis Dumort of the genus Carex L. (Cyperaceae), with special reference to the Iberian and North African taxa. Karyological studies were carried out on Iberian and North African populations of all species included in sections Spirostachyae and Ceratocystis of the genus Carex , with observations made on meiotic divisions in one to seven individuals per population. In the light of the karyological data we present hypotheses of the most probable phylogeny of the section Spirostachyae , and of the relationships of the sections Spirostachyae, Ceratocystis and Elatae. Carex laevigata and C. camposii are transferred from section Elatae to section Spirostachyae.  相似文献   

10.
Aim The angiosperm genus Cryptotaenia (family Apiaceae, tribe Oenantheae) exhibits an anomalous distribution pattern, with five of its eight species being narrow endemics geographically isolated from their presumed relatives. We examined the monophyly of the genus and ascertained the phylogenetic placements of its constituent members in order to explain their distribution patterns. Location Eastern North America, eastern Asia, the Caucasus, southern Italy, Macaronesia and Africa. Methods In total, 173 accessions were examined for nuclear rDNA ITS sequence variation, representing nearly all major lineages of Apiaceae subfamily Apioideae and seven species of Cryptotaenia. Sampling of tribes Oenantheae, Scandiceae and Pimpinelleae was comprehensive. Phylogenetic analyses included Bayesian, maximum parsimony and neighbour‐joining methods; biogeographical scenarios were inferred using dispersal–vicariance analysis (diva ). Results Cryptotaenia is polyphyletic and includes three distant lineages. (1) Cryptotaenia sensu stricto (C. canadensis, C. japonica, C. flahaultii and C. thomasii) is maintained within tribe Oenantheae; C. canadensis and C. japonica, representing an eastern North American–eastern Asian disjunction pattern, are confirmed to be sister species. (2) Cryptotaenia elegans, endemic to the Canary Islands, is placed within Scandiceae subtribe Daucinae along with two woody endemics of Madeira, Monizia edulis and Melanoselinum decipiens. The phylogeny of these Canarian and Madeiran endemics is unresolved. Either they constitute a monophyletic sister group to a clade comprising some Mediterranean and African species of Daucus and their relatives, or they are paraphyletic to this clade. The herbaceous/woody genus Tornabenea from Cape Verde, once included in Melanoselinum, is not closely related to the other Macaronesian endemics but to Daucus carota. (3) The African members of Cryptotaenia (C. africana, C. calycina and possibly C. polygama) comprise a clade with some African and Madagascan umbellifers; this entire clade is sister group to Eurasian Pimpinella. Main conclusions Elucidating the phylogeny of the biogeographically anomalous Cryptotaenia sensu lato enabled hypotheses on the biogeography of its constituent lineages. Cryptotaenia sensu stricto exhibits a holarctic distribution pattern, with its members occurring in regions that were important glacial refugia. The genus probably originated in eastern Asia and from there dispersed to Europe and North America. For the Macaronesian endemic species –C. elegans, M. edulis and M. decipiens–diva reconstructs either a single dispersal event to Macaronesia from the Mediterranean/African region, or a single dispersal followed by a back‐dispersal to the mainland. The radiation of Tornabenea from Cape Verde followed a second dispersal of Daucinae to Macaronesia. Woodiness in Melanoselinum/Monizia and Tornabenea, therefore, is a derived and independently acquired trait. The African members of Cryptotaenia are derived from an ancestor arriving from the Middle East.  相似文献   

11.
国产白酒草亚族(菊科紫菀族)由白酒草属(Conyza)、小舌菊属(Microglossa)和歧伞菊属(Thespis)3个小属组成,且国产白酒草亚族各属间及其与非洲白酒草属植物之间的分子系统发育关系尚无报道,故本研究利用核糖体DNA ITS和ETS序列并采用最大简约法和贝叶斯分析法,重建了国产白酒草亚族的分子系统发育树。结果表明,国产4种白酒草属植物、歧伞菊和非洲白酒草属植物组成一支,而劲直白酒草的两变种和小舌菊嵌入田基黄亚族分支;小舌菊与Psiadia pascalii近缘。基于这些结果,我们认为:(1)劲直白酒草和Conyza incisa应处理为田基黄亚族的一个独立的属;(2)国产4种白酒草属植物和歧伞菊以及大多数非洲白酒草属植物属于Eschenbachia属,而且Eschenbachia属代表一个新的亚族,歧伞菊可处理为Eschenbachia属的一个组。Eschenbachia属可能从非洲经数次长距离传播到达我国南部;(3)Welwitschiella和小舌菊属应保持属的地位,Psiadia pascalii、Conyza scabrida和C.pyrrhopappa可并入小舌菊属。  相似文献   

12.
The tribe Sonerileae in tropical Africa and Madagascar is a morphologically diverse lineage that consists of 239 species in 10 genera. In this study, we present the first in-depth phylogenetic analysis of African Sonerileae to test monophyly of the currently recognized genera. Phylogenetic analyses were performed using sequence data from two nuclear (nrITS and nrETS) and three plastid loci (accD-psaI, ndhF and psbK-psbL). Sampling consisted of 140 accessions including 64 African, 27 Malagasy, 46 Asian, and three neotropical Sonerileae together with a broad outgroup sampling (105 spp.). Phylogenetic relationships were inferred using maximum likelihood and Bayesian inference approaches, and a careful reassessment of morphological characters was carried out. Our results neither support the monophyly of the Old World nor African Sonerileae. The monospecific African genus Benna is partially supported as sister to Phainantha, one of the basal neotropical lineages, while African and Malagasy Medinilla are nested among the SE Asian genera. Gravesia (116 spp.), the most species-rich and morphologically diverse genus in Madagascar, is recovered as monophyletic. The African genera of Sonerileae Calvoa, Dicellandra, and Preussiella form well-supported clades. In contrast, Amphiblemma (including Amphiblemma molle) and Cincinnobotrys s.l. (including Cincinnobotrys felicis) are not monophyletic. To accommodate the caulescent C. felicis we propose reinstatement of the monospecific genus Bourdaria. For the distinctive A. molle a new genus Mendelia is described. Calvoa hirsuta is designated here as the type of genus Calvoa, lectotypes are designated for Medinilla engleri and Veprecella lutea, and a neotype is designated for Preussiella kamerunensis.  相似文献   

13.
We used three different approaches, a phylogenetic analysis, the principal component analysis, and Gabriel Graphs, to study the dispersion of the medfly from its geographic centre of origin. Our analysis was based on 13 enzyme polymorphisms detected electrophoretically in 15 natural populations coming from distinct geographic areas. The results indicate that (i) there is a clear-cut separation of the native African from the introduced populations, (ii) the population from Spain seems to connect the African and the Mediterranean or American populations, and (iii) the Mediterranean populations as well as the American ones comprise two distinct groups of closely related populations.We have also estimated a phylogenetic tree for 3 species of the genus Ceratitis: C. capitata, C. rosa and C. nigra, based on electrophoretic data under the assumption of a molecular clock. The results suggest that C. capitata and C. rosa are more closely related to each other than either is to C. nigra.  相似文献   

14.
This study examines the craniometry of Black and White Colobus monkeys using 1072 specimens representing all the recognized subspecies (after Rahm, '70) of the genus. Seventy-six measurements were taken on each individual, and examined using canonical variates analysis and clustering by Ward's Error Sum method. The assumptions of the analytical techniques are shown to be met, and the results demonstrated to be stable. Examination of the populations for statistical difference and taxonomic distinctiveness using a multivariate extension of Mayr's Rule indicates that the taxonomy presented by Rahm ('70) is essentially correct, except that the subspecies of guereza across the northern part of Central Africa should be lumped into a single group--C. g. occidentalis--and the subspecies of montane angolan colobus in Eastern Zaire should all be lumped into C. a. ruwenzorii. The systematic patterns of the genus illustrate the whole range of the process of speciation, from barely distinct subspecies, to subspecies almost as distinct as allopatric species of the genus, and on the fully sympatric species Three major zoogeographic areas may be delineated: an East African area dominated by the effects of the Rift Valley, with a large number of subspecies isolated in forest islands; a Central African area with little subspeciation and sympatric overlap of the major species of Colobus; and a West African area with a clinal pattern of distribution of subspecies, and secondary intergradation. The arbitrary nature of Mary's Rule is also apparent. Lastly, the CVA indicated major differences across the genus to be located in the teeth and jaws, suggesting diet might be an important distinguishing feature in Colobus.  相似文献   

15.
The cyprinid genus Barbus, with more than 800 nominal species, is an apparently polyphyletic assemblage to which a number of unrelated species, groups and/or assemblages have been assigned. It includes species that exhibit three different ploidy levels: diploid, tetraploid and hexaploid. Several lineages of the family Cyprinidae constitute a major component of the African freshwater ichthyofauna, having about 500 species, and fishes assigned to the genus 'Barbus' have the most species on the continent. We used complete sequences of the mitochondrial cytochrome b gene in order to infer phylogenetic relationships between diploid, tetraploid and hexaploid species of 'Barbus' occurring in southern Africa, the only region where representatives of all of the three ploidy levels occur. The results indicate that most of the lineages are incorrectly classified in the genus 'Barbus'. The southern African tetraploids probably originated from southern African diploids. They constitute a monophyletic group distinct from tetraploids occurring in the Euro-Mediterranean region (Barbus sensu stricto). The 'small' African diploid species seem to be paraphyletic, while the 'large' African hexaploid barbs species are of a single, recent origin and form a monophyletic group. The evidence of multiple, independent origins of polyploidy occurring in the African cyprinine cyprinids thus provides a significant contribution to the knowledge on the systematic diversity of these fishes, and warrants a thorough taxonomic reorganization of the genus.  相似文献   

16.
Abstract. Courtoisia , a new genus of rarely encountered taeniapterine Micropezidae (Diptera), is described from the Mascarene Islands of Réunion and Mauritius. The affinities of Courtoisia with other Old World genera of Taeniap-terinae, most notably those from the Afrotropical Region, are discussed. A possible derivation of Courtoisia from ancestral stock of the African genus Cephalosphen Hennig, 1934 is suggested. A tentative theory to explain the dispersal of a founder population from Africa to the Mascarene Islands is discussed. Courtoisia was erected to accommodate Calobata apicalis and C.trinotata , both described from Réunion by Macquart in 1851. Both species are redescribed on the basis of all available material and a lectotype is designated for Calobata trinotata. A key to the species of Courtoisia is presented.  相似文献   

17.
Three previously unknown members of the lichen genus Neofuscelia Essl. are described: N. esterhuyseniae Essl., N. nonreagens Essl., and N. pseudoloriloba Essl. New South African records for other members of the genus are given as well, and N. subimitatrix (Essl.) Essl. is reported from New Zealand for the first time. Apothecia of the recently described South African genus Almbornia Essl. have been observed for the first time and they are typically parmeliaceous.  相似文献   

18.
Middle Eocene age caesalpinioid and mimosoid legume leaves are reported from the Mahenge site in north-central Tanzania. The Mahenge flora complements a sparse Paleogene tropical African fossil plant record, which until now consisted of a single macrobotanical assemblage, limited palynological studies in West Africa and Egypt, and fossil wood studies primarily from poorly dated deposits. Mahenge leaf macrofossils have the potential to add significantly to what is known of the evolutionary history of extant African plant groups and to expand our currently limited knowledge of African Paleogene environments. The site is associated with a kimberlite eruption and demonstrates the potential value of kimberlite-associated lake deposits as much-needed resources for African Paleogene floras. In this report we document a relatively diverse component of the flora consisting of the leaves of at least five species of Leguminosae. A new species of the extant genus Acacia (Mimosoideae), described herein, is represented by a bipinnate leaf. Another taxon is described as a new species of the extant genus Aphanocalyx (Caesalpinioideae), and a third leaf type may be related to the extant genus Cynometra (Caesalpinioideae). Two additional leaf types are less well understood: one appears to be referable to the Caesalpinioideae and subfamily affinities of the other taxon are unknown.  相似文献   

19.
Abstract

Among Angiosperms, only six species are known to possess the lowest identified chromosome number, i.e. 2n = 4. These plants are the monocotyledons Zingeria biebersteiniana, Colpodium versicolor, Ornithogalum tenuifolium and Rhynchospora tenuis, and the dicotyledons Haplopappus gracilis and Brachyscome dichromosomatica. The low chromosome number may be cytogenetically derived from a different ancestral basic number, characteristic of each genus, by different processes, including tandem fusion or unequal reciprocal translocations with loss of centric fragments. All these plants possess low nuclear 4C DNA contents, ranging from 1.56 pg (R. tenuis) to 8.20 pg (H. gracilis), and they generally display a similar chromosome size and a similar position of the nucleolus organising region (NOR), that is often located in the terminal or subterminal region of the small chromosome pair. All these characteristics could be a consequence of common adaptative mechanisms. Peculiar characteristics within these karyotypes are the holocentric chromosomes of R. tenuis and the presence of B chromosomes in B. dichromosomatica. Plants with a very low chromosome number may be considered to constitute a fascinating “island of interest”; moreover, they represent simple systems helpful for the examination of the structural organisation and evolution of Angiosperm chromosomes.  相似文献   

20.
Recently, the phylogenetic placement of the African slender snouted crocodile, Crocodylus cataphractus, has come under scrutiny and herein we address this issue using molecular and morphological techniques. Although it is often recognized as being a "basal" form, morphological studies have traditionally placed C. cataphractus within the genus Crocodylus, while molecular studies have suggested that C. cataphractus is very distinct from other Crocodylus. To address the relationship of this species to its congeners we have sequenced portions of two nuclear genes (C-mos 302bp and ODC 294bp), and two mitochondrial genes (ND6-tRNA(glu)-cytB 347bp and control region 457bp). Analyses of these molecular datasets, both as individual gene sequences and as concatenated sequences, support the hypothesis that C. cataphractus is not a member of Crocodylus or Osteolaemus. Examination of 165 morphological characters supports and strengthens our resurrection of an historic genus, Mecistops (Gray 1844) for cataphractus.  相似文献   

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