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1.
Based on light and scanning electron microscopical observations, Typhlophoros kwenae n. sp. (Heterocheilidae), a new nematode parasite, is described from the stomach of the Nile crocodile Crocodylus niloticus Laurenti in South Africa. In having three lips with well-developed posterior prolongations and prominent interlabial longitudinal cuticular ridges, four pairs of precloacal papillae and complex spicules divided into handle and broad alate blade in males, as well as the position of the vulva near mid-body in females, the specimens conform to the generic diagnosis of Typhlophoros von Linstow, 1906. They can, however, be distinguished from the two previously described congeners, T. lamellaris von Linstow, 1906 and T. spratti Sprent, 1999, by the number of complete interlabial ridges, the length of spicules in males and the position of the vulva as well as the length of the tail in females. This is the first record of the genus Typhlophoros from the Afrotropical Realm.  相似文献   

2.
Conservation and management of widespread species can be improved if populations exhibiting genetic differentiation are recognized as local management units. Specimens of Nile crocodile (Crocodylus niloticus) corresponding to major river drainage systems from Eastern Africa and Madagascar, and a small set of samples from Western Africa, were analyzed using multilocus genotyping to evaluate the potential to discriminate among locations and to assign individuals to population of origin. Populations from all sampled regions exhibited marked levels of genetic and genotypic differentiation as assessed by significant F ST values and Bayesian analysis of population structure. At the regional level, the majority (94%) of all specimens were successfully assigned to the population of origin using only four microsatellite loci. Three populations sampled within Madagascar required the use of 12 loci for successful assignment of greater than 84%. Our findings demonstrate a need for alternative management strategies that consider the biogeographic sub-structuring of Nile crocodiles associated with major river drainages in Africa and Madagascar.  相似文献   

3.
Longidorus kheirii n. sp., a parthenogenetic species, was found in soil samples collected from the rhizosphere of Rosa sp. growing in a natural mountainous region close to Maragheh city, northwestern Iran. It is characterised by having a long body (6.7-9 mm), a 19.5-23 mum wide head continuous with the body contour, a truncate and slightly concave lip region with convex sides between the anterior end and the guide-ring, an odontostyle 113-130 mum long, an odontophore 69-97.5 mum long, a body width of 90.5-117.5 mum at the mid-body, a long, wide oesophageal bulb (149.5-193.5 x 39.5-48 mum), a tail length of 47-72 mum, a male with 11 ventromedian supplements and spicules of 85 mum in length, and four juvenile stages. The ribosomal 18S rDNA gene of L. kheirii n. sp., L. leptocephalus Hooper, 1961, L. profundorum Hooper, 1966 L. euonymus Mali & Hooper, 1973 and two unidentified species listed as Longidorus sp. 1 and Longidorus sp. 2, all recovered from northwestern Iran in the same survey, and the ITS1 of L. kheirii n. sp. and Longidorus sp. 1 were sequenced in order to investigate the phylogenetic relationships with other previously sequenced Longidorus species.  相似文献   

4.
Trebius Krøyer, 1838 currently consists of 15 accepted species all infecting elasmobranchs. Apart from two species, i.e. T. caudatus Krøyer, 1838 and T. latifurcatus Wilson, 1921, that have been reported from ten and eight host species, respectively, the other 13 species have each been reported from only one or two host species. Trebius benzi n. sp., collected from Squalus acutipinnis Regan, is described and illustrated after examination through stereo- and compound microscopes. This species can be distinguished from the other known species by a combination of characters including an abdomen that is shorter than the genital complex, a maxillule with an endite that consists of a single-tined dentiform process, sternal furca tines that are blunt and as long as the base, and the innermost spine of the last exopodal segment of leg 1 the shortest.  相似文献   

5.
6.
Steinernema costaricense n. sp. and S. puntauvense n. sp. were recovered during a survey for native entomopathogenic nematodes in Costa Rica. Morphological data, molecular (28S rDNA sequence data) studies and cross-hybridisation tests were used for diagnostic and identification purposes. Additionally, 28S rDNA sequence data were used to assess the evolutionary relationships of the new species with other Steinernema spp. Morphological diagnostic features for S. costaricense n. sp. include: the body size of the infective juvenile (av. 1,696); the presence of protruding 'horn-like' cephalic papillae; the position of the excretory pore in the infective juvenile (av. 77 microm) and the first generation male (av. 117 microm); the D% value of the infective juvenile (av. 53) and the first generation male (av. 56); the E% value of the infective juvenile (av. 85); and the morphology of the spicules and gubernaculum of the first generation male. Diagnostic traits for S. puntauvense n. sp. are: the position of the excretory pore in the infective juveniles (av. 25 microm); the shape and size of the spicules and gubernaculum of the first generation male; and the shape of the tail of the first generation female. In addition to these traits, 28S rDNA sequences analysis and hybridisation tests showed that both new Steinernema species are distinct and unique entities.  相似文献   

7.
Summary  Three new species are described in Barleria L. sect. Stellatohirta M. Balkwill from tropical Africa: B. aristata from south-central Tanzania, B. aenea from south-western Tanzania and northeast Zambia, and B. purpureotincta from south-western Zambia. Their affinities and conservation status are discussed.  相似文献   

8.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.  相似文献   

9.
Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.  相似文献   

10.
High-throughput screening of microalgae for use as a potential feedstock for biodiesel requires a reliable method for the rapid detection of intracellular neutral lipid content. In this study, we report a modified and improved Nile Red (NR) fluorescence staining procedure for use as a rapid and sensitive screening tool to estimate levels of intracellular neutral lipid in the picopleustonic microalgae, Nannochloropsis sp. Addition of either glycerol or dimethyl sulfoxide (DMSO) into microalgae cultures greatly enhances lipid staining efficiency and increases the fluorescence intensity of stained cells. The optimized procedure requires glycerol and DMSO at the concentration of 0.1 and 0.165 g mL−1, respectively, for peak fluorescence in a live culture of Nannochloropsis sp. Incubation for 5 min for glycerol-NR staining and 10 min for DMSO-NR staining at room temperature, in darkness, is used for the NR concentration of 0.3 and 0.7 μg mL−1 for glycerol and DMSO, respectively. For the selection of lipid-rich cells of Nannochloropsis sp. using flow cytometric cell sorting, the glycerol-NR procedure is recommended as glycerol, unlike DMSO, does not inhibit subsequent growth of sorted cells.  相似文献   

11.
Kretzschmaria varians, a species apparently related to K. micropus, is described as new. It is distinguished primarily by having asci with 2 to 8 ascospores with inconstant germination slit length and remains of synnemata on stromata and surrounding substrate. Xylaria coremiifera, described here as new, bears small fragile coremia on pulvinate stromata and the surrounding substrate. Asci often have fewer than 8 ascospores, most frequently 4. Xylaria umbonata, described here as new, produces perithecia around a central umbo that appears to be the remains of a synnema. Ascospores have long spiralling germination slits.  相似文献   

12.
Although resistance of microorganisms to Hg(II) salts has been widely investigated and resistant strains have been reported from many eubacterial genera, there are few reports of mercuric ion resistance in extremophilic microorganisms. Moderately thermophilic mercury resistant bacteria were selected by growth at 62 °C on Luria agar containing HgCl2. Sequence analysis of 16S rRNA genes of two isolates showed the closest matches to be with Bacillus pallidus and Ureibacillus thermosphaericus. Minimum inhibitory concentration (MIC) values for HgCl2 were 80 μg/ml and 30 μg/ml for these isolates, respectively, compared to 10 μg/ml for B. pallidus H12 DSM3670, a mercury-sensitive control. The best-characterised mercury-resistant Bacillus strain, B. cereus RC607, had an MIC of 60 μg/ml. The new isolates had negligible mercuric reductase activity but removed Hg from the medium by the formation of a black precipitate, identified as HgS by X-ray powder diffraction analysis. No volatile H2S was detected in the headspace of cultures in the absence or presence of Hg2+, and it is suggested that a new mechanism of Hg tolerance, based on the production of non-volatile thiol species, may have potential for decontamination of solutions containing Hg2+ without production of toxic volatile H2S.  相似文献   

13.
14.
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.  相似文献   

15.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.  相似文献   

16.
Angiostoma margaretae n. sp. (Angiostomatidae) is described from the oesophagus of the slug Milax gagates Draparnaud collected near Caledon in the Western Cape Province of South Africa. The new species closely resembles another parasite of a milacid slug, A. milacis Ivanova & Wilson, 2009, with a similar head, stoma and spicule shape, the presence of distally outstretched ovaries, coiled oviducts, the same number of caudal papillae and enlarged rectal glands. However, A. margaretae differs from the latter by having: a shorter, wider tail with a rounded vs pointed tip; the distal parts of both ovaries with a particular hook-like shape due to an expansion closely following the short initial zone; ovoviparous females; and a different arrangement of male papillae. A. margaretae is comparable with A. limacis Dujardin, 1845, A. asamati (Spiridonov, 1985), A. coloaense (Pham Van Luc, Spiridonov & Wilson, 2005) and A. stammeri (Mengert, 1953), which have a similar stoma shape and size, but can be readily differentiated by the presence of distally outstretched vs reflexed ovaries and the presence vs lack of enlarged rectal glands. The new species has a similar arrangement of the ovaries to A. kimmeriense Korol & Spiridonov, 1991 and A. zonitidis Ivanova & Wilson, 2009, but is clearly differentiated by the lack of an off-set lip region and presence of a large bowl-shaped vs tubular stoma and less numerous male caudal papillae (seven pairs vs nine in A. kimmeriense and 10 in A. zonitidis).  相似文献   

17.
A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.  相似文献   

18.
Elaphoglossum mickeliorum, a new species from the eastern slopes of the Peruvian Andes, is here described and illustrated. It belongs to E. sect. Polytrichia, which is characterized by the presence of subulate scales and absence of hydathodes on the sterile leaves of adult sporophytes. Herbarium specimens of this new species were first collected by Alwyn H. Gentry ca. 40 years ago, but these got readily confused with E. erinaceum and went undescribed since then. The new species differs from members of the E. erinaceum complex by having a nearly continuous band of planar, nonsubulate scales along the laminar margins of sterile leaves. Based on this character, E. mickeliorum resembles species such as E. glaziovii, E. ornatum, and E. scolopendrifolium. It differs from these by the presence of minute glandular hairs on petioles and costae. A distribution map and a figure with line drawings are also provided. For comparative purposes, the line drawing includes E. blepharoglottis, which is here illustrated for the first time.  相似文献   

19.
Seol E  Jung Y  Lee J  Cho C  Kim T  Rhee Y  Lee S 《Plant cell reports》2008,27(7):1197-1206
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species.  相似文献   

20.
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