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1.
We investigated roosting and hunting site fidelity of Daubenton's bats Myotis daubentonii (Kuhl, 1817) in the Forêt de Soignes, an old-stand forest dominated by 150–200-year-old beeches, during the summers of 2003 and 2004. Roosting behaviour and hunting activity over ponds of adult females and juveniles were monitored using radio-telemetry. Eighteen roosts were located, all in natural cavities. The bats occupied a limited number of trees located in a specific and small roosting area. This roost aggregation was not linked to the distribution of hollow trees. Furthermore, whereas all 11 ponds in the study area were exploited by Daubenton's bats, monitored individuals were limited to two ponds to which they showed high fidelity. These two ponds were not the closest to the roosting area. Overall, these results show that at least for the time we conducted our experiment, female and juvenile Daubenton's bats are highly faithful to specific roosting and hunting grounds. 相似文献
2.
A subfossil fragment of the deep-sea gorgonian coral Primnoa resedaeformis was 14C AMS dated along a radial growth transect. Dates ranged from 2600±50 at the outside, to 2920±60 14C years BP near the interior, suggesting an age of <300 years. The avergae radial growth was approximately 0.044 mm.yr–1. Based on comparisons with live-collected specimens, we estimate the entire colony may have been about 0.5–0.75 m tall, with a linear tip extension rate of 1.5–2.5 mm.yr–1. Towards the centre of the main stem, the coral skeleton is composed of alternating couplets, 200 m in width, of gorgonin (a horn-like organic skeletal protein) and calcite. We believe these couplets are annual. Within this larger scale of banding are finer couplets of gorgonin and calcite, with frequencies suggesting lunar monthly periodicity. Both scales of banding may reflect fluctuations in food supply from sinking POM, or from tidally-resuspended bottom POM, along with benthic consumers. Outer skeletal growth is predominantly massive calcite with intermittent gorgonin layers. If carbonate precipitation in this zone were continuous, approximately 25 m radial growth would be deposited every year. The Scleractinian Desmophyllum cristagalli lives to <200 years, and has rates of linear extension of 0.5–1.0 mm.yr–1. The skeletons show growth bands approximately 10 m wide, which may be annual. Due to tissue extension and retraction in life, parts of the skeleton may be overgrown, or suffer dissolution. Although we have shown in previous publications that sea water temperatures may be obtained from analysis of this coral, periods of skeletal dissolution, coupled with isotopic disequilibrium, will make obtaining long climatic records extremely difficult. 相似文献
3.
4.
Cocoyam (Colocasia spp.) corms and cormels showing spoilage symptoms were collected from many stores in Nsukka locality and examined for rot and associated fungal pathogens. Aspergillus niger, Botryodiplodia theobromae, Corticium rolfsii, Geotrichum candidum, Fusarium oxysporum, and F. solani were recovered from rotten cocoyams. The representative isolates of these species caused cocoyam rot in pathogenicity tests. The rot due to A. niger, B. theobromae and C. rolfsii was extensive resulting in complete maceration of cocoyam tissue. Potassium sorbate (0.1 mg/ml) protected cocoyams from fungal rot with the exception of C. rolfsii. 相似文献
5.
Summary Prey of feeding juvenile and adult Dolomedes triton (Walckenaer 1837) were sampled over two seasons on three small ponds in central Alberta, Canada. Prey were mainly insects active at the water surface with truly aquatic species making up about 14% of the diet. Throughout the season aquatic and semi-aquatic Heteroptera represented about 30% of the prey. Diptera and adult Odonata were also important prey items but their abundance in the diet was more variable seasonally. Of the 625 prey items recorded nearly 50% were represented by taxa taken no more than once by spiders in one of the five size classes (adult females, adult males, large, intermediate and small juveniles). Large spiders did not take the smallest prey available, although small and intermediate-sized spiders fed on nearly the full size range taken by larger spiders. Cannibalism was common, accounting for 5% of the observations, with females and large juveniles as the most frequently observed cannibals. We hypothesize that intraguild predation (including cannibalism) could be an important coevolutionary force structuring phenology, population dynamics and microhabitat use of the predatory guild of the neuston community. 相似文献
6.
Lavikainen A Laaksonen S Beckmen K Oksanen A Isomursu M Meri S 《Parasitology international》2011,60(3):289-295
Taenia tapeworms of Finnish and Swedish wolves (Canis lupus) and Finnish brown bears (Ursus arctos), and muscle cysticerci of Svalbard reindeer (Rangifer tarandus platyrhynchus), Alaskan Grant's caribou (Rangifer tarandus granti) and Alaskan moose (Alces americanus) were identified on the basis of the nucleotide sequence of a 396 bp region of the mitochondrial cytochrome c oxidase subunit 1 gene. Two species were found from wolves: Taenia hydatigena and Taenia krabbei. The cysticerci of reindeer, caribou and one moose also represented T. krabbei. Most of the cysticercal specimens from Alaskan moose, however, belonged to an unknown T. krabbei-like species, which had been reported previously from Eurasian elks (Alces alces) from Finland. Strobilate stages from two bears belonged to this species as well. The present results suggest that this novel Taenia sp. has a Holarctic distribution and uses Alces spp. as intermediate and ursids as final hosts. 相似文献
7.
Phage susceptibility pattern and its correlation with lipopolysaccharide (LPS) and plasmid profiles may help in understanding
the phenotypic and genotypic diversity among highly promiscuous group of rhizobia nodulating Sesbania spp.; 43 phages were from two stem-nodulating bacteria of S. rostrata and 16 phages were from root-nodulating bacteria of S. sesban, S. aegyptica and S. rostrata. Phage susceptibility pattern of 38 Sesbania nodulating bacteria was correlated with their LPS rather than plasmid profiles. Different species of bacteria (A. caulinodans- ORS571, SRS1-3 and Sinorhizobium saheli- SRR907, SRR912) showing distinct LPS subtypes were susceptible to different group of phages. Phages could also discriminate
the strains of Si. saheli (SSR312, SAR610) possessing distinct LPS subtypes. Phages of Si. meliloti (SSR302) were strain-specific. All the strains of R. huautlense having incomplete LPS (insignificant O-chain) were phage-resistant. In in vitro assay, 100% of the phages were adsorbed to
LPS of indicator bacterium or its closely related strain(s) only. These observations suggest the significance of LPS in phage
specificity of Sesbania nodulating rhizobia. Highly specific phages may serve as biological marker for monitoring the susceptible bacterial strains
in culture collections and environment. 相似文献
8.
In Japan, zooxanthellate Palythoa tuberculosa Klunzinger and Palythoa mutuki Verrill (Anthozoa: Hexacorallia: Zoantharia) are found over a 1,000 + km latitudinal range, often in environments where most
other zooxanthellate anthozoans are not found (i.e. tidal lagoon pools, around shallow water hydrothermal vents, subtropical
rocky shorelines). Sequences of internal transcribed spacer of ribosomal DNA (ITS-rDNA) of the symbiotic dinoflagellate genus
Symbiodinium (zooxanthellae) Freudenthal (Order Suessiales) from P. tuberculosa and P. mutuki from several locations in Japan (34°11′N–24°16′N) were analysed. Unexpectedly, despite the ability of the genus Palythoa to be flexible in association with different Symbiodinium subclades, most (35 of 36) Palythoa investigated here specifically associate with subclade C1 and closely related types. Symbiodinium subclade C1 has been characterized as a “generalist” in terms of the ability to associate with a range of hosts, but present
results suggest that subclade C1 may also be a “generalist” in terms of being able to live in a variety of environments over
a latitudinal range.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
9.
Inoculation with ectomycorrhizal fungi was explored as a means to improve productivity of experimental short-rotation plantations of the willowsSalix viminalis andSalix dasyclados for biomass production on surface-mined peatlands in northern Finland. Both willow species formed ectomycorrhizas withAmanita spp.,Cortinarius purpurascens, Entoloma nidorosum, otherEntoloma spp.,Hebeloma crustuliniforme, H. pusillum, Laccaria bicolor, andPaxillus involutus in greenhouse experiments.Field trials on a mined peatland site revealed (after one growing season) statistically significant growth stimulation after inoculation due to mycorrhiza formation in both willow species: plants inoculated withEntoloma were sometimes twice as large as control plants. However, such effects were observed only in plots receiving normal phosphate fertilization as opposed to low phosphate application, and were not consistent from season to season. With the inoculum of other species (Cortinarius, Hebeloma andPaxillus) some evidence of growth enhancement was found in the field, but these results were sometimes attributable to non-symbiotic effects of inoculation. 相似文献
10.
Anna Bertrand-Desbrunais Michel Noirot André Charrier 《Plant Cell, Tissue and Organ Culture》1991,27(3):333-339
We have studied the influence of low concentrations of 6-benzyladenine on growth limitation, in order to preserve coffee germplasm through a microcutting collection. Concentrations of 0 M, 1.3 M and 4.4 M were compared in four species: Coffea congensis, C. canephora, C. liberica and C. racemosa. After six months, microcutting behaviour varied between the different treatments, and a species effect was observed. The slow growing species (C. liberica and C. congensis) needed 1.3 M; the others coffee species (C. canephora and C. racemosa) exhibited moderate caulogenesis on 6-benzyladenine-free medium. Zero and low concentrations did not affect survival rates. In conclusion 1.3 M seems most appropriate for conserving all four species.Abbreviation BA
6-benzyladenine 相似文献
11.
Michael Stuart Vickie Pendergast Susan Rumfelt Suzanne Pierberg Lisa Greenspan Kenneth Glander Margaret Clarke 《International journal of primatology》1998,19(3):493-512
A literature review of howler parasites provides the basis for an overview of the ecological significance of parasite surveys in primates. Within this framework, we have added insights into the interactions between primate hosts and their parasites from a long-term study in Costa Rica. We collected fecal samples from mantled howlers (Alouatta palliata) over a 9-year period (1986–1994 inclusive) and analyzed them for parasite eggs, larvae, cysts, and oocysts. We found many misperceptions inherent in the typical methodology of primate parasite surveys and in the reporting of the findings. Our work in Costa Rica suggests that a snapshot effect occurs with most surveys. A static view does not reflect the dynamic and changing ecological interaction between host and parasite. We describe some problems with parasite data analyses that emphasize the need for long-term longitudinal surveys in wild primate groups. 相似文献
12.
H. Huang F. Dane J. D. Norton 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,88(8):981-985
Allozyme genetic variability in three chestnut (Castanea) species was investigated using 19 loci from ten enzyme systems. G-tests of heterogeneity of isozymic allele distribution showed significant differences between the three species at 15 of the 19 loci, and between the 13 C. mollissima populations at 13 of the 19 loci examined. C. mollissima was found to possess a significantly-higher value of mean gene heterozygosity (H=0.3050±0.0419), the percentage of polymorphic loci (P=84.21%) and the average number of alleles per locus (A=2.05), than any other species in the Castanea section Eucastanon. When the genetic variability of populations of C. mollissima from four regions in China was investigated, the population from the Changjiang river region showed a markedly higher mean gene heterozygosity (H=0.3480±0.0436) than populations from the other regions. Genetic relationships among the four regions were assessed by Nei's genetic identity I and standard genetic distance D. An approximately-identical distance between the population from the Changjiang river region and populations from the three other regions was observed, while populations from the latter regions showed almost the same genetic distance from each other. These data, when considered with information existing prior to this study, contribute to an understanding of the possible origin and progenitor of the chestnut species. 相似文献
13.
Much of the ecology of rare bumblebee species remains poorly understood and in need of further study. It has recently been suggested that differences in the range and rate of decline among bumblebee species may relate to differences in their degree of habitat specialization. We examine biotope use by 17 bumblebee species in the Hebrides, southern UK and South Island, New Zealand. We identify a cluster of widespread and abundant species that occur in almost all biotopes and exploit man-made environments such as gardens and arable margins, this group corresponding to the “mainland ubiquitous” species of previous studies. A second grouping of species includes those associated to varying degrees with heathland. It is notable that some species occupy markedly different biotopes in different parts of their range; for example B. soroeensis is found largely on upland heaths in the Hebrides, but on calcareous grassland in the south. Some species, such as B. subterraneus and B. distinguendus, now survive only in specific rare biotopes and could be mistaken for habitat specialists, but it is clear from their historic distributions that they formerly occupied a broader range of biotopes. Surviving populations of several of the species that have declined most (B. distinguendus, B. sylvarum, B. muscorum sladeni, B. humilis) exhibit a markedly coastal distribution, when once they were widespread inland. We suggest that this is probably simply because some coastal biotopes are less amenable to agricultural improvement, and so more have escaped the detrimental effects of intensive farming. Our results concur with previous suggestions that bumblebees are generally not habitat specialists, so that the conservation of most bumblebee species could be achieved by restoration of flower-rich unimproved meadows. 相似文献
14.
Slow growth in vitro conservation of coffee (Coffea spp.) 总被引:1,自引:0,他引:1
Anna Bertrand-Desbrunais Michel Noirot André Charrier 《Plant Cell, Tissue and Organ Culture》1992,31(2):105-110
The effects of reduced sucrose concentrations and low temperature on a collection of coffee microcuttings have been examined. Sucrose concentrations of 0.5 g l-1 and 20 g l-1 and temperatures of 20°C and 27°C were compared in three accessions: the Arabusta (interspecific hybrid) and Coffea arabica L. cv. Caturra amarillo and cv. Mokka de Tahiti. After six months, low sucrose concentrations reduced microcutting growth, rooting and survival rate. At 20°C, microcutting growth was also reduced, but leaf loss and survival rate were promoted. The genotypic differences at six months were minor. After one year without subculture, survival rate was influenced by sucrose concentration and by genotype. These two species can be cold-stored six months at 20°C on a medium containing at least 20 g l-1 sucrose.Abbreviations BA
6-benzylaminopurine
- MS
Murashige & Skoog 相似文献
15.
Nina M. Cadiz Jorge M. Vivanco Hector E. Flores 《In vitro cellular & developmental biology. Plant》2000,36(4):238-242
Summary We have established an in vitro system for the induction and study of nodulation in Pachyrhizus erosus (jicama) via a hairy root-Rhizobium coculture. In vitro-grown P. erosus plantlets were infected with Agrobacterium rhizogenes (ATCC No. 15834) and two hairy root lines were established. Hairy roots were grown in a split-plate system in which compartment
I (CI) contained MS medium with nitrogen and different sucrose levels (0–6%), while CII held MS medium without nitrogen and
sucrose. Nodule-like structures developed in transformed roots grown in CI with 2–3% surcose, inoculated with Rhizobium sp. and transferred to CII. Nodule-like structures that developed from hairy roots lacked the rigid protective cover observed
in nodules from plants grown in soil. Western blot analysis of nodules from hairy roots and untransformed roots (of greenhouse-grown
jicama) showed expression of glutamine synthetase leghemoglobin and nodulins. Leghemoglobin was expressed at low levels in
hairy root nodules. 相似文献
16.
Regvar M Vogel K Irgel N Wraber T Hildebrandt U Wilde P Bothe H 《Journal of plant physiology》2003,160(6):615-626
Members of the Brassicaceae are generally believed to be non-mycorrhizal. Pennycress (Thlaspi) species of this family from diverse locations in Slovenia, Austria, Italy and Germany were examined for their colonisation by arbuscular mycorrhizal fungi (AMF). Meadow species (T. praecox, T. caerulescens and T. montanum) were sparsely but distinctly colonised, as indicated by the occurrence of intraradical hyphae, vesicles, coils, and occasionally arbuscules. Species from other locations were poorly colonised, but arbuscules were not discernible. The genus Thlaspi comprises several heavy metal hyperaccumulating species (T. caerulescens, T. goesingense, T. calaminare, T. cepaeifolium). All samples collected from heavy metal soils were at best poorly colonized. Thus the chance is small to find a "hypersystem" in phytoremediation consisting of an AM fungus which prevents the uptake of the major part of the heavy metals and of a Thlaspi species which effectively deposits the residual heavy metals inevitably taken up into its vacuoles. In two different PCR approaches, fungal DNA was amplified from most of the Thlaspi roots examined, even from those with a very low incidence of AMF colonization. Sequencing of the 28S- and 18S-rDNA PCR-products revealed that different Thlaspi field samples were colonized by Glomus intraradices and thus by a common AM fungus. However, none of the sequences obtained was identical to any other found in the present study or deposited in the databanks, which might indicate that a species continuum exists in the G. intraradices clade. An effective colonization of Thlaspi by AMF could not be established in greenhouse experiments. Although the data show that Thlaspi can be colonized by AMF, it is doubtful whether an effective symbiosis with the mutual exchange of metabolites is formed by both partners. 相似文献
17.
Samples of dying branches from 121 trees of Quercus pubescens, Q. cerris, and Q. petraea were taken from 102 sites in Seslerio autumnalis-Quercetum petraeae and Ostryo-Quercetum pubescentis forests. After nine months’ rearing in eclectors, branches were cut to 20-cm sections, and signs of infestation as well as
larvae and adult insects were noted. We analysed 395 sections of branches from Q. pubescens, 125 sections from Q. cerris, and 85 sections from Q. petraea. We found 44 adult insects: 45% were from the Cerambycidae family (Callimus angulatus ssp. angulatus, Poecilium alni, and Exocentrus adspersus), 18% were from the Scolytinae subfamily (Scolytus intricatus, Xyleborus dispar), 4% from the Buprestidae family (Coraebus florentinus), 4.5% from the Cleridae family (Tilloidea unifasciata), and 28.5% from other families. In addition, 145 larvae were found: 50% from the Cerambycidae family, 39% from the Buprestidae
family, 4% from the Scolytinae subfamily, and 7% from other families. Significant difference in the abundance of adult insects
and larvae with regard to the diameter of branch sections and the host species were found. 78% of dying branches showed signs
of infestation. Species of the Buprestidae, Scolytinae, and Cerambycidae represent important factors in the decline in oak
vitality in the lower Karst region of Slovenia. 相似文献
18.
Little is known of the biology of most insects that are endemic to prairie ecosystems of North America, with the exception of large and conspicuous species. In particular, species that are sequestered within plant tissues are commonly overlooked. In this paper, we assess the biodiversity of endophytic insects that inhabit stems of Silphium laciniatum L. and S. terebinthinaceum Jacquin (Asteraceae), endemic plants of tallgrass prairies. Endophytic herbivores, gall wasps Antistrophus rufus Gillette and A. minor Gillette (Hymenoptera: Cynipidae) and stem-boring larvae of the beetle Mordellistena aethiops Smith (Coleoptera: Mordellidae) were attacked by 10 species of natural enemies. We report new host plant associations for herbivores, and new host insect associations for parasitoids. The two plant species differed significantly in their densities of gall wasps and the vertical dispersion of galls within stems. Interactions within and between trophic levels attest to the biodiversity of endophytic insect communities, and the specialized nature of these insects suggests they are highly vulnerable to habitat conservation practices that involve destruction of dead vegetation. 相似文献
19.
The stomach contents of 517 eels were analysed during 1979. In that particular year the diet consisted predominantly of chironomids, but large bivalve molluscs were of secondary importance. The meaning of this observation is discussed in relation to food conditions and the food preference of the eel. 相似文献
20.
Reeves WK Loftis AD Szumlas DE Abbassy MM Helmy IM Hanafi HA Dasch GA 《Experimental & applied acarology》2007,41(1-2):101-107
We collected and tested 616 tropical rat mites (Ornithonyssus bacoti (Hirst)) from rats (Rattus norvegicus (Berkenhout) and R. rattus (Linnaeus)) throughout 14 governorates in Egypt and tested DNA extracts from pools of these mites for Bartonella spp., Coxiella burnetii, and Rickettsia spp. by PCR amplification and sequencing. Three different mite-associated bacterial agents, including one Bartonella and two Rickettsia spp., were detected in eight pools of mites. Further research could demonstrate the vector potential of mites and pathogenicity
of these agents to humans or animals.
The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers
for Disease Control and Prevention. 相似文献