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1.
The microfungi of three palm species were investigated in their natural habitats and in habitats where the palms were cultivated outside their natural ranges. The palms that were selected differed in their habitats and ecology. Archontophoenix alexandrae is endemic to tropical rainforests in Australia, Cocos nucifera is pan‐tropical and Trachycarpus fortunei occurs in warm‐temperate China. Different assemblages of fungi were found in association with palms in temperate regions as compared to those in tropical regions. These differences were more related to climatic influences than to the hosts sampled, as few fungi were host‐species specific. The status of the hosts at the site, i.e. indigenous or introduced, and the degree of disturbance of the habitats within which the palms grew were also influential. When sampled in its natural habitat, Archontophoenix alexandrae had a distinct palmicolous mycota typical of other palms in tropical rainforests. Outside of the palm’s natural habitat, a widely different mycota were recorded that comprised tropical species of a more plurivorous nature. A similar plurivorous assemblage characterized the fungi associated with Cocos nucifera, probably due to the palm’s long history of cultivation. Similarly, plurivorous, but temperate or widespread fungi were associated with Trachycarpus fortunei, both within and outside of its natural habitat. This palm is also highly cultivated. A reduction in palm fungi associated with palms in disturbed habitats has implications for conservation of these fungi. However, it is acknowledged that the data for fungal diversity and distribution is incomplete and fragmentary.  相似文献   

2.
Lepidopteran stem borers are among the most important insect pests of maize, sorghum and sugarcane in sub‐Saharan Africa. Except for Chilo partellus, the other stem borer pests in Ethiopia are indigenous to Africa and are assumed to have coevolved with some native grasses and sedges in the natural habitat. In addition to pest species, natural habitats harbour diverse non‐economic stem borer species, some of which are new to science. However, with the growing threats to natural habitats, some non‐economic stem borer species may switch or expand their host ranges to include cultivated crops and evolve as “new” pests. Besides host switch, some of the unknown species currently limited to natural habitats may disappear. We examined the diversity, abundance and interactions of lepidopteran stem borers and their wild host plants in five different vegetation mosaics in Ethiopia. The stem borer species diversity varied among vegetation mosaics and host plants. Forty‐four stem borer species belonging to 14 different genera in the families of Noctuidae, Crambidae, Pyralidae and Tortricidae were recorded from 34 wild host plants and through light trap. Among these families, Noctuidae was the highest in species richness in which 31 species were identified, out of which 15 species and two genera were new to science. This paper discusses the ecological interpretation of host plant–stem borer species interactions, particularly in relation to habitat disturbances.  相似文献   

3.
The ground cricket Dianemobius nigrofasciatus overwinters as an egg in Japan, being univoltine in Hokkaido and northern Honshu and bivoltine farther south. In Hokkaido, however, this cricket is heard singing in winter in several fumarolic fields covered with moss and grasses locally known as “bokke”. In such warm “islets” the adult density was high in early summer and again in autumn, indicating that the cricket is bivoltine in contrast to the univoltine life cycle outside the bokke habitats in Hokkaido. Eggs laid by females collected at regular intervals from a bokke habitat showed a clear seasonal cycle of diapause incidence. At 26°C, the bokke strains produced non‐diapause eggs under long days and diapause eggs under short days as in the southern bivoltine populations, although the critical day‐length was longer than in the south. Several strains derived from non‐bokke habitats in Hokkaido and northern Honshu produced high percentages of diapause eggs under long days as well as short days as expected for the univoltine life cycle. Winter adults singing in bokke habitats could be either survivors of the autumn generation or individuals derived from eggs laid in autumn and then matured in response to the high soil temperature. In the laboratory, the proportion of egg diapause in short days was decreased by selection only for several generations. Phylogenetic trees of bokke and non‐bokke populations, based on both the nucleotide sequence of the mitochondrial COI gene and four allozyme loci, suggest that bokke populations have not been isolated from non‐bokke populations for an evolutionarily significant time.  相似文献   

4.
The origin of the Eurasian grapevine, Vitis vinifera L. and the different steps in the development of viticulture from the wild grapevine to the modern varietal situation in the Iberian Peninsula are reviewed here. The ancestors of Vitis vinifera subs. sylvestris, the only representative of the Vitis genus in natural Eurasian and North African ecosystems, appeared in the late Miocene. In the Iberian Peninsula, human action has significantly reduced the habitat of this species, whose oldest palaeobotanical remains go back to the late Pleistocene. The introduction of viticulture in Iberia is connected with the relationships between the indigenous population and the trading colonies founded by Phoenicians and Greeks. In this way, there is evidence of wine production and consumption, even as a ritual and prestige item, going back to the third millennium BP. Chloroplast genome studies carried out in wild and cultivated plants indicate that a secondary domestication process occurred in the Iberian Peninsula and this is reflected in the “A” chlorotype, which contrasts with the predominance of the “B” and “C” chlorotypes in wild and domesticated vines in the Transcaucasian region, where domesticated grapes at sites of the Shulaveri Culture (Georgia) are evidence of early viticulture around 8000 BP.  相似文献   

5.
Aim We use Cardamine alpina and C. resedifolia as models to address the detailed history of disjunctions in the European alpine system. These species grow on siliceous bedrock: C. alpina in the Alps and Pyrenees, and C. resedifolia in several mountain ranges from the Sierra Nevada to the Balkans. We explore differentiation among their disjunct populations as well as within the contiguous Alpine and Pyrenean ranges, and compare the phylogeographical histories of these diploid sister species. We also include samples of the closely related, arctic diploid C. bellidifolia in order to explore its origin and post‐glacial establishment. Location European alpine system, Norway and Iceland. Methods We employed amplified fragment length polymorphisms (AFLPs). AFLP data were analysed using principal coordinates analysis, neighbour joining and Bayesian clustering, and measures of diversity and differentiation were computed. Results For the snow‐bed species C. alpina (27 populations, 203 plants) we resolved two strongly divergent lineages, corresponding to the Alps and the Pyrenees. Although multiple glacial refugia were invoked in the Pyrenees, we inferred only a single one in the Maritime Alps – from which rapid post‐glacial colonization of the entire Alps occurred, accompanied by a strong founder effect. For C. resedifolia (33 populations, 247 plants), which has a broader ecological amplitude and a wider distribution, the genetic structuring was rather weak and did not correspond to the main geographical disjunctions. This species consists of two widespread and largely sympatric main genetic groups (one of them subdivided into four geographically more restricted groups), and frequent secondary contacts exist between them. Main conclusions The conspicuously different histories of these two sister species are likely to be associated with their different ecologies. The more abundant habitats available for C. resedifolia may have increased the probability of its gradual migration during colder periods and also of successful establishment after long‐distance dispersal, whereas C. alpina has been restricted by its dependence on snow‐beds. Surprisingly, the arctic C. bellidifolia formed a very divergent lineage with little variation, contradicting a scenario of recent, post‐glacial migration from the Alps or Pyrenees.  相似文献   

6.
Many of the genes that control photosynthesis are carried in the chloroplast. These genes differ among species. However, evidence has yet to be reported revealing the involvement of organelle genes in the initial stages of plant speciation. To elucidate the molecular basis of aquatic plant speciation, we focused on the unique plant species Chara braunii C. C. Gmel. that inhabits both shallow and deep freshwater habitats and exhibits habitat‐based dimorphism of chloroplast DNA (cpDNA). Here, we examined the “shallow” and “deep” subpopulations of C. braunii using two nuclear DNA (nDNA) markers and cpDNA. Genetic differentiation between the two subpopulations was measured in both nDNA and cpDNA regions, although phylogenetic analyses suggested nuclear gene flow between subpopulations. Neutrality tests based on Tajima’s D demonstrated diversifying selection acting on organelle DNA regions. Furthermore, both “shallow” and “deep” haplotypes of cpDNA detected in cultures originating from bottom soils of three deep environments suggested that migration of oospores (dormant zygotes) between the two habitats occurs irrespective of the complete habitat‐based dimorphism of cpDNA from field‐collected vegetative thalli. Therefore, the two subpopulations are highly selected by their different aquatic habitats and show prezygotic isolation, which represents an initial process of speciation affected by ecologically based divergent selection of organelle genes.  相似文献   

7.
Comparative morphology of Antarctic spiny plunderfishes of the genus Harpagifer from the littoral and sublittoral zones off South Georgia (Scotia Sea) is investigated. A new species H. permitini from the depth 65–80 m is described and the littoral H. georgianus Nybelin, 1947 is redescribed. The significant differences in their morphology are shown. Two morphological and bathopathic forms (“soft” and “spiny”) of spiny plunder-fishes are characterized.  相似文献   

8.
The predominant view regarding Asian rice domestication is that the initial origin of nonshattering involved a single gene of large effect, specifically, the sh4 locus via the evolutionary replacement of a dominant allele for shattering with a recessive allele for reduced shattering. Data have accumulated to challenge this hypothesis. Specifically, a few studies have reported occasional seed‐shattering plants from populations of the wild progenitor of cultivated rice (Oryza rufipogon complex) being homozygous for the putative “nonshattering” sh4 alleles. We tested the sh4 hypothesis for the domestication of cultivated rice by obtaining genotypes and phenotypes for a diverse set of samples of wild, weedy, and cultivated rice accessions. The cultivars were fixed for the putative “nonshattering” allele and nonshattering phenotype, but wild rice accessions are highly polymorphic for the putative “nonshattering” allele (frequency ~26%) with shattering phenotype. All weedy rice accessions are the “nonshattering” genotype at the sh4 locus but with shattering phenotype. These data challenge the widely accepted hypothesis that a single nucleotide mutation (“G”/“T”) of the sh4 locus is the major driving force for rice domestication. Instead, we hypothesize that unidentified shattering loci are responsible for the initial domestication of cultivated rice through reduced seed shattering.  相似文献   

9.
Phlox cuspidata (n = 7) and P. drummondii subsp. drummondii (n = 7) are closely related annuals which are indigenous to eastern and central Texas. The species typically occupy different ecological niches but may form contiguous or confluent populations in disturbed habitats and hybridize therein. On the basis of correlative interpretations of exomorphic, chromatographic and fertility information, hybridizing populations can be segregated into three distinct classes: (1) highly fertile plants with the morphological and phenolic attributes of P. drummondii; (2) highly fertile plants with the morphological and chemical attributes of P. cuspidata; (3) sterile plants with manifestly intermediate morphology and complementary chromatographic patterns. These data strongly suggest that hybridizing populations of P. drummondii and P. cuspidata are tritypic, being composed of “pure” or essentially “pure” parental species and a group of plants which has all of the attributes characteristic of an F1 hybrid.  相似文献   

10.
The compound eyes of the deep-sea mysid Boreomysis scyphops and the two mysid species Amblyops abbreviata and Pseudomma affine, which are indigenous to deep fiords in Norway, have been investigated. The eye stalks are greatly transformed, but contain hypertrophied retinas. The ommatidia of all three species lack a dioptric apparatus, possessing only retinular cells, which are arranged in a cylinder-like fashion. Folds from the retinular cells project into the “cylinder” and are covered with microvilli. The arrangement is explained functionally by an increase in the photopigment-bearing surface as an adaptation to low-light intensities. The orderly arrangement of microvilli in most arthropod compound eyes has been lost, and the arrangement is thus multidirectional in these mysids. With the photopigment dipoles arranged along the microvillar axis, the disorderly arrangement of microvilli signifies a more efficient capture of non-polarized light. It is concluded that the mysid compound eyes show adaptations to low-light intensities probably acquired during the species' evolutionary descent into deep-sea habitats. Amblyops abbreviata and Pseudomma affine, belonging to genera with entirely transformed eyes and with an ultrastructure less “normal” than that of Boreomysis scyphops are believed to be earlier descendants into the deep-sea habitats than the latter species, which belongs to a genus in which most of the species have well-developed eyes.  相似文献   

11.
Delphinine dolphins arose via a recent, rapid radiation, probably within the last four million years. Although molecular phylogenies are increasingly well resolved, patterns of morphology-ecology-geography are hard to link to phylogeny or to translate into taxonomy. Such problems might be tackled through understanding the drivers of the delphinine radiation. Here, we examine delphinine historical biogeography using the phylogeny of McGowen et al. (Mol Phylogenet Evol 53:891–906, 2009) as our working hypothesis. We used the Spatial Analysis of Vicariance” method to delimit modern distribution patterns, including disjunctions involving sister nodes in the Delphininae. The analysis identified disjunct sister nodes, allowing some interpretation of Delphininae biogeography. The Central American Seaway was probably an important gateway for early delphinids, but the succeeding “hard” barrier of the Panama Isthmus had little influence. Southern African waters form the Atlantic-Indo-Pacific gateway, which is sometimes considered a “soft” barrier because of the variation in the Benguela and Agulhas currents, in turn driven by tectonic changes and/or Pleistocene glacial and interglacial cycles. The latter cycles probably fragmented coastal habitats, allowing allopatric speciation. Geological patterns of turnover in Southern Ocean diatoms, which link to physical oceanic change, closely match the main cluster of delphinine divergences. The Eastern Pacific Barrier, and perhaps the associated Humboldt Current and equatorial “cold tongue,” affect modern distributions, but cause and effect are poorly understood. Future research should involve molecular-morphological phylogenetics for all species, subspecies, and ecomorphs. Complete distributions must be known for all taxa to understand how vicariance and dispersal shaped the distribution of delphinines.  相似文献   

12.
Lepidopteran stemborers are amongst the most important insect pests of maize, sorghum and sugarcane in sub-Saharan Africa. With the exception of Chilo partellus (Swinhoe), which was accidentally introduced into Africa, the other stemborer pests are indigenous to the continent and have co-evolved with native grasses and sedges. In addition to pest species, wild habitats harbour diverse non-economic stemborer species, some of which are new to science. However, the diversity and distribution of both non-economic and pest species of stemborer are currently mostly unknown in Botswana. Accordingly, country-wide surveys were conducted during 2014/15 and 2015/16 austral summer to determine species diversity and distribution in cultivated and wild host plants of stemborers in Botswana. A total of 1597 stemborer larvae and 228 pupae were collected, constituting 63.1 and 36.9 larvae and 84.8 and 15.2% pupae from cultivated versus wild habitats, respectively. In addition to C. partellus, Sesamia calamistis Hampson and Eldana saccharina Walker which were previously reported, 12 more stemborer species were recorded for the first time in Botswana, including nine undescribed species. These species were from the Sciomesa, Sesamia and Conicofrontia genera and Tortricidae and Pyralidae families. Fourteen wild host and two cultivated host plant species of stemborers were recorded. Chilo partellus was most abundant (89.5%) in cultivated habitats whilst E. saccharina (33.6%) was most abundant in wild habitats. Stemborer species diversity was higher in wild habitats than cultivated. Current results highlight the significance of wild, especially wetland habitats for ecological functions and conservation of lepidopteran stemborer biodiversity.  相似文献   

13.
A growing number of molecular studies show that many fungi have phylogeographic structures and that their distinct lineages are usually limited to different continents. As a conservative test of the extent to which wind-dispersed mycorrhizal fungi may exhibit phylogeographic structure, we chose to study Amanita muscaria, a host-generalist, widespread, wind-dispersed fungus. In this paper, we document the existence of several distinct phylogenetic species within A. muscaria, based on multilocus DNA sequence data. According to our findings, A. muscaria has strong intercontinental genetic disjunctions, and, more surprisingly, has strong intracontinental phylogeographic structure, particularly within North America, often corresponding to certain habitats and/or biogeographic provinces. Our results indicate that the view of A. muscaria as a common, widespread, easily identifiable, ecologically plastic fungus with a wide niche does not correctly represent the ecological and biological realities. On the contrary, the strong associations between phylogenetic species and different habitats support the developing picture of ecoregional endemisms and relatively narrow to very narrow niches for some lineages.  相似文献   

14.
Freshwater aquifers in granitic rocks are widespread microbial habitats in the terrestrial subsurface. Microbial populations in deep granitic groundwater from two recently drilled (1 and 2 years) and two old boreholes (14 and 25 years) were compared. The 16S rRNA gene sequences related to “Candidatus Magnetobacterium bavaricum”, Thermodesulfovibrio spp. of Nitrospirae (90.5–93.1 % similarity) and a novel candidate division with <90 % similarity to known cultivated species were dominant in all boreholes. Most of the environmental clones closely related to the novel lineages in Nitrospirae, which have been detected exclusively in deep groundwater samples. In contrast, betaproteobacterial sequences related to the family Rhodocyclaceae were obtained only from the recently drilled boreholes, which had higher total cell numbers. Catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) analysis supported the result from clone library analysis; betaproteobacterial cells were dominantly detected in recently drilled boreholes. These results suggest that while indigenous microbial populations represented by the novel phylotypes persisted in the boreholes for 25 years, betaproteobacterial species disappeared after 2 years owing to the change of substrate availability.  相似文献   

15.
The identity of Simulium murmanum is re-established by designation of lectotype and paralectotype. The species is common and widespread in the northern Holarctic Region and has up to now been reported from the Nearctic Region as S. corbis and from the Palaearctic Region as S. relictum (and S. rostratum, auct., nec Lundstrüm).  相似文献   

16.
Marine interstitial environments are teeming with an extraordinary diversity of coexisting microeukaryotic lineages collectively called “meiofauna.” Interstitial habitats are broadly distributed across the planet, and the complex physical features of these environments have persisted, much like they exist today, throughout the history of eukaryotes, if not longer. Although our general understanding of the biological diversity in these environments is relatively poor, compelling examples of developmental heterochrony (e.g., pedomorphosis) and convergent evolution appear to be widespread among meiofauna. Therefore, an improved understanding of meiofaunal biodiversity is expected to provide some of the deepest insights into the following themes in evolutionary biology: (i) the origins of novel body plans, (ii) macroevolutionary patterns of miniaturization, and (iii) the intersection of evolution and community assembly – e.g., “community convergence” involving distantly related lineages that span the tree of eukaryotes.  相似文献   

17.
18.
Casearia sylvestris Sw. is a widespread neotropical tree utilized in popular medicine. Recent research ranked Casearia as one of the most promising genus in the search of drugs against cancer. Despite its wide distribution and pharmacological importance, no microsatellite markers have yet been developed for this genus. In this study, we provide 10 polymorphic microsatellite loci specifically designed for C. sylvestris, used to analyse 90 individuals distributed in two populations from São Paulo state, Brazil. On average, 12.3 alleles per locus were identified, showing the ability of the markers to detect microsatellite polymorphism in this species.  相似文献   

19.
Many tiny yellow poppies are grown in the town area of Rishiri Island, Japan. Because the phenotype of this cultivated poppy is similar to that of Papaver fauriei, which is endemic to Mt. Rishiri, Rishiri Island, residents on the island call the cultivated poppy “P. fauriei” although the origin of the cultivated poppy is uncertain. To estimate the origin of the cultivated poppy, its internal transcribed spacer (ITS) sequence was compared with those found in the Far East wild poppies P. fauriei, P. alboroseum, P. miyabeanum and P. nudicaule. Although the ITS sequence of the cultivated poppy was not identical to those found in the wild species, it was most similar to that of P. miyabeanum, indicating that the cultivated poppy is not P. fauriei. However, cultivated poppy seeds have been sown several times over a period of at least 20 years in wild P. fauriei habitats on Mt. Rishiri in the hope of aiding the recovery of P. fauriei populations in wild habitats. Poppy plants in the wild habitats where such seeds have been sown showed the same ITS sequences as those of the cultivated poppy, indicating that the cultivated poppy is established in these wild habitats. This is a case of a nonindigenous species being introduced to wild habitats through human actions.  相似文献   

20.
Understanding the dynamics of pest insect populations in relation to the presence of non‐crop habitats and infestation levels of adjacent crops is essential to develop sustainable pest management strategies. The invasive pest species Drosophila suzukii (Diptera: Drosophilidae) is able to utilize a broad range of host plants. In viticulture, scientific risk assessment for D. suzukii has only recently started and studies assessing the effects of field margins containing wild host plants on D. suzukii population dynamics and on infestation risks in adjacent vineyards are lacking. Thus, in a one‐year field study, the role of different field margins on fly abundance and crop infestation in adjacent vineyards of Vitis vinifera, variety “Pinot Noir,” were investigated. Different monitoring methods were conducted to assess fly distribution, sex ratio and grape infestation in 14 vineyards adjacent to field margins containing either blackberry (BB) Rubus spp. or non‐host (NH) plants. Our results show that blackberries strongly enhanced D. suzukii abundance within field margin vegetation all year long, whereas fly abundance in vineyards adjacent to BB margins was just enhanced in some seasonal periods. Moreover, the influence of BB margins was limited by distance. However, high fly numbers in BB field margins did result in zero egg infestation of “Pinot Noir” berries. These results may have important implications for winegrowers to make efficient management decisions: regardless of high abundance of adult D. suzukii, only grape berry monitoring can assess the actual infestation risk and the potential need to take management action.  相似文献   

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