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1.
Chrysomya Robineau-Desvoidy (Diptera: Calliphoridae) is a genus of blowfly commonly observed in tropical and subtropical countries of the Old World. Species in this genus are vectors of bacteria, protozoans and helminths, cause myiasis, are predators of other carrion insects, and are important forensic indicators. Hypotheses concerning the evolution of sex determination, larval anatomy and genome size in Chrysomya have been difficult to evaluate because a robust phylogeny of the genus was lacking. Similarly, the monophyly of subgenera was uncertain. The phylogeny of Chrysomya spp. was reconstructed based on 2386 bp of combined mitochondrial cytochrome oxidase subunit I (COI) and nuclear carbamoylphosphate synthetase (CPS) genes. Maximum parsimony (MP), maximum likelihood (ML) and Bayesian analysis (BA) differed only slightly in the resulting tree topology. Chrysomya was monophyletic. Monogenic reproduction is almost certainly derived rather than, as has been suggested, primitive within the genus, and tuberculate larvae probably evolved twice. Genome size is more likely to have decreased over evolutionary time rather than, as has been suggested, increased within the genus, but its correlation with developmental time was not observed. The subgenera Microcalliphora, Eucompsomyia and Achoetandrus were recovered as monophyletic.  相似文献   

2.
本文对金缕梅科马蹄荷属及其各种植物的拉丁学名和异名进行了考证,确认Exbucklandia R. W. Brown是该属有效的拉丁学名,Bucklandia R. Brown et Griff. 和Symingtonia Steenis作为异名。  相似文献   

3.
Three different Latin names, i.e. Bucklandia R. Brown ex Griff., Symingtonia Steenis and Exbucklandia R. W. Brown, have been used for the same genus of the Hamamelidaceae in various botanical books and papers for a long time. Symingtonia Steenis has been widespread and cited as a valid Latin name for this genus. However, the present author found Exbucklandia R. W. Brown to be the only valid Latin name fro this genus and suggested to treat the other two Latin names as synonyms of this genus. The nomenclatural notes for the species are presented in the paper.  相似文献   

4.
It has been suggested in the literature that primates of the genus Cacajao have been restricted to flooded-forest habitats of western Amazonia since their split from the Chiropotes line in the Tertiary. It has been proposed further that the differentiation of the two species of this genus, Cacajao melanocephalus and Cacajao calvus, occurred during the Pleistocene period as a result of the fragmentation of the Amazon forest and the isolation of populations in these forest fragments or refuges. However, recent evidence has shown that at least C. melanocephalus is not dependent on flooded-forest habitats, and molecular analysis of mitochondrial DNA shows that the two species had already differentiated during the Pliocene, thus Pleistocene glaciations do not explain the speciation in Cacajao. Considering that C. melanocephalus and its closest relative, Chiropotes, inhabit terra firme forests, it is suggested that preference for flooded-forest habitats may be an apomorphy in C. calvus.  相似文献   

5.
Erika Stix 《Grana》2013,52(1):24-32
The pollen morphology of the 16 recognized species of the genus Asphodelus L. (Asphodelaceae) has been investigated by light and scanning electron microscopy. Four pollen types can be distinguished on the basis of variation in size of the polar, equatorial longitudinal and transverse axes, as well as in exine structure and sculpturing, which correlate with the subdivision of the genus into sections. Correlations between pollen size and some biological characters are made. Phylogenetic implications are suggested, and trends of pollen evolution in the genus are indicated.  相似文献   

6.
A technique has been suggested for individual maintenance of intermediate hosts of Schistosoma mansoni, molluscs of the genus Biomphalaria, in thermostat water bath with thermoregulator in order to study the host-parasite relationships in the mollusc-trematode system. Advantages of the suggested technique have been shown for studying total production of Cercaria when estimating the compatibility degree of various strains of S. mansoni and races of molluscs of some species of the genus Biomphalaria.  相似文献   

7.
8.
Geoffrey  Fryer 《Journal of Zoology》1982,196(4):453-462
A new lernaeid copepod of the genus Afrolernaea parasitic on mormyrid fishes from Gabon is described. A fin parasite, this species has been found only on the inner face of the pectoral fins. The new species is the most primitive member of the genus yet discovered and the structure of its appendages throws light on the nature of the anchoring hooks of the more advanced species, and on the probable course of evolution within the genus. The suggested affinities of the species of the genus are indicated in a dendrogram.  相似文献   

9.
The phylogeny of the African orchidoid genus Brownleea was investigated, using morphological characters. It has been suggested that the genus may be of hybrid origin, a hypothesis supported by the presence of two very different types of stigma ontogenies. Morphological investigations of all the species revealed that two species have stigmas derived from all three carpel apices, the 'normal' situation in the Orchidaceae. The remaining five species have stigmas derived from only the median carpel, a very unusual situation found in the Coryciinae. A phylogenetic analysis of all available morphological data for all species supports the monophyly of the genus. based on several distinct synapomorphies. The variation in stigma ontogeny may be due either to parallelism, or to an earlier hybridization event. The analysis supported the recognition of several distinct groupings within Brownleea . Two of these groupings are supported irrespective of which putative parent is used as sister-group to the genus, while a third grouping is dependent on the use of the as sister-group.  相似文献   

10.
N. M. Nayar 《Genetica》1967,38(1):521-527
The prevalence of self-incompatibility inOryza barthii Cheval. and its implications on the origin of riceO. sativa L. and some other related taxa are discussed. It is suggested that evolution has been fromO. barthii toO. perennis toO. sativa with corresponding changes in breeding system from allogamy to facultative autogamy to obligate autogamy. The significance of the breeding system for speciation and evolutionary potentialities of these three taxa is pointed out. The presence inO. barthii of the most primitive characters of the genus and its widespread presence in tropical Africa (where nine out of 23 species of the genus occur) have been interpreted as suggesting that this region might have been the centre of origin of the genus.  相似文献   

11.
The systematic knowledge of Simpsonichthys has changed substantially in recent years, with five subgenera having been elevated to the genus category. In view of these taxonomic changes, the aim of the present study was to identify the phylogenetic relationships among this group in order to test a hypothesis of the division of Simpsonichthys. The ATPase 8 and 6 gene sequences of 53 specimens of Simpsonichthys, Xenurolebias, Ophthalmolebias, Spectrolebias and Hypsolebias genera were assessed. The final topology divided the Simpsonichthys subgenera into five clades: clade I (Hypsolebias antenori group and Ophtalmolebias), clade II (Simpsonichtys and Spectrolebias), clade III (Hypsolebias flammeus and H. magnificus groups), clade IV (H. notatus group) and clade V, which included the Xenurolebias genus as a sister group to all the other Simpsonichthys subgenera. Simpsonichthys, Spectrolebias and Hypsolebias could therefor not be described as monophyletic groups, as has been proposed in some hypotheses. The H. antenori, H. notatus and H. magnificus groups, however, were monophyletic. The molecular results also suggested that H. ocellatus belongs to the Hypsolebias flammeus group. The phylogenetic position of H. fasciatus suggested a new group within Hypsolebias, or possibly even a new genus. The characteristics of the Hypsolebias antenori group and their phylogenetic position suggested that only the species of this group should be included in the Hypsolebias genus. The basal position of the Hypsolebias notatus group and its morphological character may represent a new genus. Although the monophyletism of Simpsonichtys could not be recovered, the branches supported the division of the western and eastern clades, possibly due to allopatric speciation. These facts suggest the division of the genus into at least two major clades. In addition, the study of morphological and molecular data is suggested to obtain a better understanding of such complex organisms, and a major taxonomic review is required.  相似文献   

12.
13.
The endangered Uluguru Bush Shrike Malaconotus alius is a large, black-headed bush shrike, strictly endemic to the Uluguru Mountains in Tanzania. It has recently been suggested that this species has been misplaced within the genus Malaconotus and might instead be related to Malagasy Vangidae. To assess its systematic affinities, we analysed 1518 bp of sequence data obtained from a nuclear intron (myoglobin intron-2) and a mitochondrial protein-coding gene (ND2) using parsimony, maximum likelihood and Bayesian inference. Both genes strongly support the traditional placement within the genus Malaconotus , suggesting that similarities between the Uluguru Bush Shrike and the Vangidae are due to convergence. These results caution that taxonomic changes should not be made without a proper character analysis (i.e. assignment of character homology).  相似文献   

14.
The family Cephalotaxaceae contains so far known only 1 genus with 8 species and possibly 2-3 varieties mostly native in China. In recent years, some ester alkaloids of Cephalotaxus have been shown significant activity in a variety of experimental leukemia systems. 6 species (including varieties) of the genus have been investigated for their alkaloids. The detected alkaloids in Cephalotaxaceous plants, from the chemotaxonomic point of view, may be of some significance to the plant systemstics. Our present study has indicated that: (1) The species C. sinensis and C. fortunei (C. oliveri ?) are chemically considered to be more primitive than others, while C. harringtonia, C. hainanensis and C. wilsoniana (including C. mannii?) seem to be derived. (2) Chemical evidence has suggested that the genus Cephalotaxus be accorded a family rank. (3) On the basis of morphology, anatomy, embryogeny, geographical distribution etc., the recent findings in the chemistry of Cephalotaxaceae support the inclusion of Cephalotaxaceae, Taxaceae and Podocarpaceae in Taxineae of Coniferales. (4) C. fortunei, C. hainanensis and C. oliveri (C. harringtonia) contain richer ester alkaloids than other species of the genus. C. fortunei which has a wide distribution and great amount in many provinces of China, may prove to be a good new resource for antitumor medicine.  相似文献   

15.
Simple yet comprehensive identification of anaerobic bacilli is possible to genus level when typical susceptibility patterns of antimicrobial substances are used in combination with the morphological characteristics of the bacteria. Paper discs were soaked with fosfomycin (100 μg), colistin (10 μg), everninomicin B (10 μg) and metronidazole (2 μg) and tested on sheep blood agar in a jar under anaerobic conditions. A dichotomous scheme has been suggested for the differentiation of the following genera: Actinomyces, Bacteroides, Bifidobacterium, Clostridium, Eubacterium, Fusobacterium, Lactobacillus, Leptotrichia, Propionibacterium and Selenomonas. The method gave preliminary results which can be used as guidance for subsequent species identification and for therapeutic advice, as antibiotic susceptibility depends very much on the genus of anaerobic bacilli.  相似文献   

16.
《Journal of bryology》2013,35(2):269-273
Abstract

Spores of ten North European species of the genus Tortula Hedw. were studied in the transmission electron microscope. In all the sporoderm was more or less covered with finely papillate processes of several different types which divide the genus into a number of groups different from the previously suggested sections. The ornamentation of leaves, peristomes, and spores of T. norvegica (Web. f.) Wahlenb. has been studied in the scanning electron microscope. The leaf papillae are not c-shaped as suggested in the literature, but branched in a rather complex way. The borders of the basal membrane cells of the peristome appeared to be a continuation of the filamentous portion of the teeth. A comparison with T. ruralis (Hedw.) Gaertn., Meyer & Scherb. revealed the ornamentation to be of the same basic type in the two species.  相似文献   

17.
Toarctocera, a new gastropod genus of the family Aporrhaidae (Stromboidea) is described for Rostellaria subpunctata. It occurs in Central Europe (S Germany, N Switzerland, and France) and is commonly one of the most abundant gastropods in Late Toarcian/Early Aalenian soft bottom faunas. Toarctocera subpunctata has extremely elongated apertural spines; this has been interpreted as an adaptation to extremely soft-bottom conditions (snowshoe strategy). The new genus represents one of the earliest certain aporrhaids (Stromboidea). Aporrhaids are probably as old as Late Triassic, and possible Triassic and Early Jurassic species are discussed. Spiniloma is proposed as a nomen novum in order to replace the homonym Spinigera and consequently the family Spinilomatinae replaces the Spinigeridae. The sister group of Stromboidea still needs to be identified. A previously suggested sister group relationship with the Heteropoda is seen as unlikely.  相似文献   

18.
Dispersed fungal spores from the Reading Beds (Palaeocene) near Newbury, Berkshire are referred to the genus Pesavis Elsik & Jansonius, and a possible affinity with aero-aquatic fungi is suggested. This highly distinctive Palaeogene sporomorph has not previously been described from the European Tertiary.  相似文献   

19.
Two forms of a large and flightless rail (takahe) belonging to the genus Porphyrio and endemic to New Zealand have been described, although their taxonomy has been repeatedly questioned. Analyses of osteometric data from modern and Quaternary fossil material show such a degree of allometric distinctiveness that it is considered that the two forms are, indeed, different species as originally described, Porphyrio mantelli (Owen), Porphyrio hochstetteri (Meyer). It is suggested that this degree and type of difference could have resulted from the two species arising independently from similar volant ancestors.  相似文献   

20.
Species in the genus Echis have been classified mainly based on their morphological appearance and the analytical patterns of their serum. However, re-classification of the genus Echis has recently been suggested by taxonomists, toxicologists, and clinicians, since there have been problems with the current classification, such as the efficacy of antivenoms used for treating bites and the broad geographical distribution of Echis snakes. In this study, we purified five novel disintegrins, the platelet aggregation inhibitors pyramidin A and B from the venom of Echis pyramidum, ocellatin from the venom of Echis ocellatus, and leucogastin A and B from the venom of Echis leucogaster, to compare their sequences and allow us to re-evaluate the classification of various species in the genus Echis. Comparison of the amino acid sequences of five new and four known isolated disintegrins from snake venoms of six Echis species and their distribution strongly support the recent re-classification of the genus Echis.  相似文献   

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