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Juniperus navicularis is an endemic taxon of Iberian Peninsula that develops on paleodunes of coastal ecosystems and whose distribution range is not well defined. In this paper, we present the results of the morphological analysis in populations attributed to J. navicularis of southern Spain. In order to assess the similarity between Portuguese and Spanish populations, the Mann–Whitney U test was performed, the same test was also applied between this taxon and Juniperus oxycedrus subsp. oxycedrus. In order to distinguish this species from other taxa of the Juniperus oxycedrus group (subsp. oxycedrus, subsp. badia, subsp. macrocarpa) in the southwestern Mediterranean region, a principal component analysis has been carried out. New data about the chorology and ecology of Spanish populations considered as a priority habitat in the Habitat Directive as well as number of individuals and conservation status are provided.  相似文献   

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Dermatocarpon (Verrucariales, lichenized Ascomycotina) in the Nordic countries is revised. The following 10 species occur: D. bachmannii, D. deminuens, D. leptophyllodes, D. leptophyllum, D. linkolae, D. luridum, D. meiophyllizum, D. miniatum, D. polyphyllizum , and D. rivulorum. Three varieties of D. miniatum , viz. var. miniatum , var. cirsodes , and var. complicatum , are also discussed. A key to the species is given, and distribution maps for all species are supplied. Useful characters for the recognition of different species are discussed.  相似文献   

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A conspicuous, new species of the bivalve genusGervilleioperna occurs in coarse-grained bioclastic limestones and mixed siliciclastic-carbonate sediments of nothern Chile between 27° and 29° 40′ S. It is assigned to the new subgenusGervilleiognoma [type species:Gervilleioperna (Gervilleiognoma) aurita n. sp.], which appears to be endemic to northern Chile. On the basis of associated ammonites, the stratigraphic distribution of the new species can be restricted to the Early Aaleman (Manflasensis Zone) and thus it is of biostratigraphic value. The reconstructed life habit was mainly semi-endobyssate, resting on the thickened umbonal and anterior parts of the lower valve; the slightly twisted plane of commissure is oriented in an oblique position with respect to the substrate surface. The palaeogeographic distribution of the genus is briefly discussed.  相似文献   

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Six taxa, representing five species of Entoloma (Fr.) Kumm. subgen. Pouzaromyces (Pilat) Moser emend. Noordel. are described from Norway, of which four are new to the country, viz., E. dysthales (Peck) Sacc, E. dysthaloides Noordel., E. araneosum (Quel.) Moser i.fulvostrigosum (Berk. & Br.) Noordel., and E. versatilis (Fr.) Moser.  相似文献   

8.
Reproductive ecology (pollination biology, breeding systems, and reproductive effort and success) of the three Nordic species of Pinguicula, P. alpina, P. villosa , and P. vulgaris (Lentibulariaceae), was investigated in a subarctic-subalpine area at Abisko, N Swedish Lapland. Additional studies were carried out at Latnjajaure Field Station, a subarctic-alpine tundra site in the Abisko mountains ( P. alpina, P. vulgaris ), and in W Greenland ( P. vulgaris ). At Abisko the species are sympatric and large populations of all three were found within a 50 × 50 m area. The three species are reproduc-tively isolated by internal barriers by occupying different ploidy levels. Pinguicula alpina and P. vulgaris thrive in base-rich habitats, whereas P. villosa is restricted to nutrient-poor Sphagnum bogs, but habitat separation alone is probably not sufficient to prevent illegitimate pollen flow among the species. However, results showed that there are large and consistent differences in pollination biology, flowering phenology, and breeding systems, and these factors interact to create a highly efficient reproductive isolation at all levels, pre-zygotic as well as post-zygotic. Pinguicula alpina is an early-flowering outbreeder, P. vulgaris is an opportunistic late-flowering inbreeder, and P. villosa is quite intermediate between the two extremes. The phenology-based life history strategies of the Pinguicula species were in accordance with a general model developed for arctic flowering plants, predicting maximized fitness through pollen or seed in early- and late-flowering species, respectively.  相似文献   

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Rhizomnium (Broth.) Kop. is represented in the Iberian Peninsula by two taxa: Rhizomnium punctatum (Hedw.) Kop. and R. magnifolium. R. punctatum is common in the northern part of the Peninsula while R. magnifolium, new taxon for the Spanish bryoflora, is restricted to the high mountains of the northern half of the Peninsula. The distribution maps, the phytogeography and ecology of both species are given. All samples from herbaria named as R. pseudopunctatum correspond to R. punctatum or R. magnifolium.  相似文献   

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Cortinarius coalescens Kärcher & Seibt is a rare European species of the subgenus Phlegmacium, section Phlegmacioides, neglected in recent molecular studies. New primers (CortF and CortR) designed for species in the section Phlegmacioides allowed to obtain ITS rDNA sequence data from the holotype collection of C. coalescens; according to the results, this epithet has priority over C. crassorum Rob. Henry ex Rob. Henry, C. pardinus Reumaux, and C. parargutus Bidaud, Moënne-Locc. & Reumaux. Morphological and ecological observations on recent collections of C. coalescens from the Czech Republic in comparison with the co-occurring C. largus are discussed. Nomenclatural and taxonomic comments on C. tomentosus Rob. Henry, C. balteatotomentosus Rob. Henry, and C. subtomentosus Reumaux are also provided. So far, C. coalescens is known with certainty from Germany, France, and the Czech Republic, where it grows in deciduous forests on acid to neutral soils. Arsenic and its compounds were determined in C. coalescens and related species of the section Phlegmacioides: C. largus, C. pseudodaulnoyae, and C. variecolor. Total arsenic concentrations were in the range 3.6–30.2 mg kg?1 (dry matter) and arsenobetaine was the major arsenic compound.  相似文献   

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ABSTRACT

Aegilops L. includes wild species from which, over millennia, man has cultivated forms of Triticum L. Ten species of Aegilops occur in Italy. Three species are allochthonous and eight out of ten species are recorded in the Apulia region. Five out of the ten species have been included in Red Lists. Each taxon is presented and discussed, citing old and new sites of occurrence, by examining specimens from many different herbaria, and describing their ecology and habitats, according to the Directive 92/43 EEC. A new taxonomic key, for the identification of all Aegilops species growing in Italy, is provided. The occurrence of Aegilops caudata L., A. peregrina (Hack. in J. Fraser) Maire & Weiller and A. speltoides Tausch in Italy is doubtful.  相似文献   

13.
Miscanthus subgen. Rubimons (B. S. Sun) Y. C. Liu et H. Peng, a new subgenus of Miscanthus Anderss. (Poaceae) is established and Miscanthus (Rubimons) villosus Y. C. Liu et H. Peng, a new species of this subgenus from southwest Yunnan, China, is described and illustrated. It is closely related to M. paniculatus (B. S. Sun) S. L. Chen & Renvoize, but differs mainly by its villous panicle axis, long callus hair, lanceolate lower lemma and the consistently longer awn of the upper lemma.  相似文献   

14.
Of the many types of freshwater bodies across Iceland (e.g., lakes, springs, rivers, and ponds), greater effort has been invested in researching the freshwater Crustacea (Cladocera, Copepoda) of more permanent, larger, and deeper water bodies than on smaller or more ephemeral sites. To address this, we described the fauna of 12 shallow freshwater bodies distributed from the coast to the central highlands of Iceland. We identified 16 species in 11 genera belonging to six families of Cladocera, and 12 species in eight genera belonging to four families of Copepoda. Five of the species we identified (Alona werestschagini, Cyclops vicinus, Daphnia cristata, Diacyclops abyssicola, and Heterocope borealis) represent new distribution records for Iceland, increasing the number of species now known from this region to 34 Cladocera and 38 Copepoda taxa. Additionally, we discuss the taxonomy of some species with doubtful taxonomical status. Six crustacean taxocenes are described, each characterized by the dominance of different taxa, with bottom sediment characteristics best explaining species assemblage structure. We evaluated the relationships between Icelandic Cladocera and Copepoda faunas and those of the adjacent Svalbard, Faroe, and Shetland Islands, Greenland, and the mainland Norway. The taxonomic composition of the Icelandic fauna is dominated by widely distributed Holarctic, and secondarily Palaearctic and Nearctic species, and is more similar to the faunas of the major North Atlantic islands (64.2–71.8 % similarity) than it is to that of continental Norway.  相似文献   

15.
Most blackberry species are apomictic but pseudogamous, i.e. embryo development is dependent on prior pollination. Two different types of stamen arrangement were noted in senescing flowers of 18 Swedish species and 2 common cultivars. The stamens of 'cross-pollinating' species seldom touch the stigmas while those of 'self-pollinating' species instead arch over the pistils and dry up in this position. All species set seed well after artificial self-pollination and are thus self-compatible. Isolation experiments were carried out during 3 years. When inflorescences were bagged, seed set was drastically lowered in 'cross-pollinators' but remained almost unaltered in 'self-pollinators'. The different responses to isolation are probably due to the inherent stamen behaviour.  相似文献   

16.
InRubus L. a connection seems to exist between the degree of meiotic disturbances on the one hand, and the production of unreduced embryo sacs, pollen fertility and relative seed set on the other hand. Severe meiotic disturbances commonly encountered in apomictic taxa decrease pollen fertility and thereby seed set since pollen is necessary for endosperm development. By contrast interspecific hybrids between apomictic taxa appear to be sexual and exhibit high pollen fertilities, probably due to an improved meiosis. Thus, apomixis leads to a decreased fertility inRubus, not the opposite, as often discussed.  相似文献   

17.
The dogroses ( Rosa Sect. Caninae ) are characterized by a unique meiosis-the canina meiosis-that results in restricted recombination. In the present study, we investigate population differentiation and morphometric diversity within six taxa of Nordic dogroses, with the help of automated image analysis of leaflet shape and manually-measured reproductive characters. The total morphometric diversity in each character type was partitioned into its hierarchical components. The within-taxon structure of diversity in leaflet shape is similar (in both rank and magnitude) to the within-taxon structure of reproductive character diversity in all the taxa, with the between-population component of diversity accounting for the majority of the total diversity. The within-taxon structuring of diversity in the dogroses is comparable to that found in selfers and in species characterized by restricted recombination (such as permanent translocation heterozygotes). The relatively high within-and between-family components of diversity in R. dumalis subsp. dumalis may be a reflection of a heterogeneous genome and/or of a higher degree of outcrossing than in the other dogrose taxa. Rosa rubiginosa is characterized by low overall levels of intraspecific variation. There is weak geographic differentiation between populations of R. dumalis subsp. dumalis (in leaflet shape) and R. rubiginosa (in reproductive characters). The study provides no support for the division of R. dumalis into subsp. dumalis and subsp. coriifolia but, in contrast, shows a clear separation between varieties umbelliflora and venusta within R. sherardii.  相似文献   

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Recent reports on patterns and occurrence of torpor and other natural hypothermic states in birds have prompted a revision of many longstanding opinions. For instance, a larger assortment of birds covering a wider range of body mass than previously recognized uses energy-conserving mechanisms in the face of abundant food supplies. Thus, although acute energetic stress triggers the occurrence of hypometabolic states in many birds, energy deficits can no longer be regarded as the sole stimulus for avian torpor. Additionally, the phenology of this phenomenon (phases, duration, depth) shows more interspecific variation than previously appreciated, and traditional concepts of the phases of torpor are not always adequate. Hence, inclusive definitions of torpor based on physiological and/or behavioral criteria have become more difficult to formulate. However, average nighttime body temperature, which is highly consistent throughout the class Aves (38.54 degrees +/- 0.96 degrees C, n = 202), provides a convenient reference for detecting natural hypothermic states. Of the putative ecological factors associated with avian torpor, food specialization seems a prime candidate as an ultimate factor in the occurrence of this state in birds. With few exceptions, all of these animals capable of torpor are either frugivorous, nectarivorous, or insectivorous, suggesting a correlation between thermoregulatory pattern and predictability of food supply. To date, no clear answer exists as to whether the variety of thermoregulatory patterns evident in birds involves discrete mechanisms or merely steps in a physiological continuum. However, I suggest that the occurrence of differences in torpor patterns among closely related species (e.g., within families) favors the latter interpretation.  相似文献   

20.
Silene subgenusPetrocoptis comprises sexual diploid taxa and it is restricted to calcareous cliffs in the Iberian peninsula. Artificial crosses involvingSilene pyrenaica (Bergeret)Mayol etRosselló (≡Petrocoptis pyrenaica (Bergeret)Walp.),Silene laxipruinosa Mayol etRosselló andS. montserratii subsp.crassifolia (Rouy)Mayol etRosselló (≡P. crassifolia Rouy) were attempted to assess the extent of barriers developed within the subgenusPetrocoptis. Usually, intraspecific crosses involving allopatric populations were successful, suggesting that geographically isolated populations are not genetically isolated. Cross-compatibility was noted among the polymorphicS. pyrenaica, which developed fertile F1 hybrids. All other interspecific crosses failed due to cross- or seed-incompatibility. Crossing results agree with available evidence supporting the merging of segregates ofS. pyrenaica within a single taxon.  相似文献   

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