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1.
Summary.  Fritillaria gussichae (Degen & Dörfl.) Rix is described and illustrated and its relationship to other species in the F. graeca complex is discussed. Instructions for its cultivation are given.  相似文献   

2.
The geographic variation inFritillaria graeca, an endemic of Greece, is explored, using multivariate techniques. Eleven morphological features were measured in each of 630 individual plants from 38 localities throughout the range of the species.Scheffe's a posteriori test revealed an almost continuous geographic variation and did not identify groups clearly. Discriminant analysis of the groups derived from an F significance test ofMahalanobis distance resulted in five major groups on the first two discriminant axes representing the subspeciesgraeca, ionica, guicciardii, thessala and its var.othria. A diagnostic key to theF. graeca subspecies is provided.This paper is a part of a doctoral dissertation dealing withFritillaria in Greece, to be submitted to the department of Biology of the Aristotelian University of Thessaloniki.  相似文献   

3.
Seed protein electrophoresis of four chromosomes races ofFestuca arundinacea, F. mairei and their progenitors showed variation in banding patterns. High protein similarities betweenF. arundinacea, F. mairei, F. scariosa, andF. pratensis indicate close phylogenetic relationships of these species. The ancestry ofF. arundinacea cytotypes could be narrowed to three diploid species:F. scariosa, F. pratensis, andF. rubra or to their close relatives.  相似文献   

4.
5.
The main factor of differentiation at six nuclear microsatellite and seven cpDNA loci in Salicornia from the Mediterranean and Atlantic coasts of France is cytotypic identity, suggesting the presence of a strong reproductive barrier among sympatric cytotypes. Within cytotypes, a substantial proportion of the differentiation between species is due to confounded phylogeographic signal. Conspecific individuals tend to be significantly more related than individuals from different species at the population scale, but mean kinship coefficients among pairs of conspecific and nonconspecific individuals from different populations are not significantly different, suggesting the absence of reproductive isolation among species of the same cytotype. The observed association between morphology and genetic variation within populations would thus result from the selfing mating system (F(is)) = 0.70) generating substantial linkage within the genome, linkage that would quickly disappear among unrelated individuals from different populations. Salicornia species thus function as a network of inbred populations, strongly challenging taxonomic concepts.  相似文献   

6.
Chromosome inversions may be involved in adaptation and speciation. We investigate ecological diversification among members of the Simulium arcticum species complex at different stages of chromosome divergence. Our analyses focus on two geographical scales. First, we assess ecological divergence of sibling species throughout North America using niche modelling methods. Then, using canonical correspondence analysis, we investigate habitat associations of sibling species and cytotypes in the northern Rocky Mountains ecoregion, where cytotypes tend to occur. Despite significant overlap in predicted distributions, all sibling species are ecologically unique. On the other hand, we discover various degrees of ecological divergence for cytotypes. Some cytotypes are ecologically distinct and perhaps are in their initial stages of incipient speciation. Other cytotypes are ecologically associated with one another or with particular sibling species. Thus, for members of the S. arcticum complex, ecological and chromosomal differences tend to develop early in lineage formation. Ecological distinctiveness of sibling species and cytotypes suggests that local adaptation may be involved in diversification of these chromosomal forms. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115 , 13–27.  相似文献   

7.
Karyotypes and chromosome polymorphism of phytophilous chironomids Endochironomus tendens F. from the basin of the Saratov and Samara regions are analyzed. A cytophotomap of polytene chromosomes of this species is refined. Estimated chromosome sequences were catalogued and inversions based on them were identified. The cytotypes of Endochironomus tendens F. (I and II) are analyzed.  相似文献   

8.
The brown frog Rana graeca was believed to be present in two areas, the Balkan Peninsula and the Italian Apennines. We have characterised the S1 satellite DNA family from Rana graeca graeca and compared it with that of Rana graeca italica. On Southern blots, the patterns of S1 satellite DNA bands are very different between Italian and Greek specimens, but homogeneous among various populations of the same taxon. The satellite DNA from the Greek taxon contains two repetitive units (S1a (494 bp) and S1b (363 bp)) that could be sequenced after amplification from genomic DNA to directly yield their consensus sequences in each genome. These consensus sequences were very similar among the Greek populations, but differed either in sequence (in S1a) or in both size and sequence (in S1b) from the corresponding repeats of the Italian taxon. A mechanism of concerted evolution is likely responsible for the high homogeneity of S1a and S1b repeat sequences within each genome and species. The genomic content of S1 satellite DNA was lower in the Greek than in the Italian populations (0.5 vs. 1.9%) and fluorescence in situ hybridization (FISH) analysis showed the S1 satellite on only 4 chromosome pairs in the Greek taxon and on all 13 chromosome pairs in the Italian taxon. The completely different structure and genomic organization of the S1 satellite DNA indicate that the Greek and Italian taxa are distinct species: R. graeca and R. italica.  相似文献   

9.
The Arabidopsis arenosa complex is closely related to the model plant Arabidopsis thaliana. Species and subspecies in the complex are mainly biennial, predominantly outcrossing, herbaceous, and with a distribution range covering most parts of latitudes and the eastern reaches of Europe. In this study we present the first comprehensive evolutionary history of the A. arenosa species complex, covering its natural range, by using chromosome counts, nuclear AFLP data, and a maternally inherited marker from the chloroplast genome [trnL intron (trnL) and trnL/F intergenic spacer (trnL/F-IGS) of tRNA(Leu) and tRNA(Phe), respectively]. We unravel the broad-scale cytogeographic and phylogeographic patterns of diploids and tetraploids. Diploid cytotypes were exclusively found on the Balkan Peninsula and in the Carpathians while tetraploid cytotypes were found throughout the remaining distribution range of the A. arenosa complex. Three centers of genetic diversity were identified: the Balkan Peninsula, the Carpathians, and the unglaciated Eastern and Southeastern Alps. All three could have served as long-term refugia during Pleistocene climate oscillations. We hypothesize that the Western Carpathians were and still are the cradle of speciation within the A. arenosa complex due to the high species number and genetic diversity and the concurrence of both cytotypes there.  相似文献   

10.

Background  

To help conservation programs of the endangered spur-thighed tortoise and to gain better insight into its systematics, genetic variation and evolution in the tortoise species Testudo graeca (Testudines: Testudinidae) was investigated by sequence analysis of a 394-nucleotide fragment of the mitochondrial 12S rRNA gene for 158 tortoise specimens belonging to the subspecies Testudo graeca graeca, Testudo graeca ibera, Testudo graeca terrestris, and a newly recognized subspecies Testudo graeca whitei. A 411-nucleotide fragment of the mitochondrial D-loop was additionally sequenced for a subset of 22 T. graeca, chosen because of their 12S gene haplotype and/or geographical origin.  相似文献   

11.
There is growing realization that intraspecific polyploidy in plants has important implications for the evolution of plant diversity and for plant and plant-herbivore community dynamics. Nonetheless, the rate at which polyploid cytotypes arise and their fate in local mixed-cytotype populations are not well understood. Although within- and especially among-population cytotype variation has been documented in many plants, particularly at the largest (continental) spatial scales, local and regional distributions of cytotypes have been well characterized only for a handful of species. Furthermore, few if any studies have addressed both local and regional patterns in the same plant species with sufficient power to detect cytotype variation on both scales. We assessed the co-occurrence and frequency distributions of diploid, tetraploid, and hexaploid cytotypes of Solidago altissima (Asteraceae) at local and regional spatial scales, sampling across a zone of presumed ploidy-form overlap in the midwestern United States. Determining ploidy by flow cytometry, we found many local populations containing two or three cytotypes, with the relative frequencies of cytotypes varying dramatically even among neighboring populations. AFLP marker data suggest that polyploid cytotypes of S. altissima likely have multiple origins from different diploid lineages. Our results are consistent with recent perspectives on polyploidization as an evolutionarily dynamic phenomenon with frequent multiple origins of higher-ploidy cytotypes.  相似文献   

12.
In many North American prairies, populations of Andropogon gerardii Vitman (Poaceae) are composed of hexaploid and enneaploid cytotypes (2 n  = 60, 90), with intermediates occurring occasionally. Under controlled pollination, the two common cytotypes can be crossed, producing progeny with a range of chromosome numbers. In an investigation of fertility and compatibilities of intermediate cytotypes, individuals with chromosome numbers between 60 and 90 were crossed with each other, with the 2 n  = 60 and 90 cytotypes, and with South American Andropogon species having 60 chromosomes. Regardless of cytotype, all A. gerardii plants had some fertility and virtually all crosses produced seeds. Cytotype is only partially predictive of fertility. Inter-specific hybrids between A. gerardii and South American hexaploid species were vigorous but sterile. Gene flow in natural A. gerardii populations of mixed cytotype probably involves plants of all cytotypes.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 95–103.  相似文献   

13.
The red-legged (Alectoris rufa) and rock (A. graeca) partridges hybridize and produce fertile offspring along a contact zone in French Southern Alps. The rally call emitted during pair formation, could play an important role in species recognition, acting as a behavioral reproductive isolating mechanism between males and females. In the present study, the coding system of the rally call was investigated from captive males of the two species and from F1 hybrids. By playing-back natural signals, we found that the two species as well as hybrid males responded to Alectoris signals but not to another species belonging to the Phasianidae family (Colinus virginianus). Results also indicate that red-legged and rock partridges responded stronger to conspecific calls than to heterospecific ones. However, they reacted similarly to conspecific and hybrid calls. F1 hybrids responded stronger to hybrids calls than to the two species ones. They did not distinguish the two parental species signals from each other. Although the two species showed the ability to discriminate the conspecific from the heterospecific signal, they clearly responded to the other species. This behaviour may play a role in the hybridization phenomenon.  相似文献   

14.
Sexual dimorphism of body size and shell shape in European tortoises   总被引:1,自引:0,他引:1  
Adult body size and shape were examined in almost 1400 individuals of the tortoises Testudo graeca , T. hermanni and T. marginata from Greece. The size at maturity was greater in females than in males in all three species. Maximum and mean adult sizes were also greater in females than in males in T. graeca and T. hermanni . Males grew to a larger size than females in T. marginata , and mean adult size was similar in the sexes in this species. Sexual dimorphism of shape (adjusted for size covariate) was shown in most of the characters examined, and the degree of this dimorphism differed significantly among the three species. Differences were related to their contrasting courtship behaviours: horizontal head movements and severe biting in T. marginata , vertical head bobs and carapace butting in T. graeca , and mounting and tail thrusting in T. hermanni . There was no difference in the frequency of observations of courtship or fighting among the three species, but courtship was about 10 times more common than combat in males. All species showed greatest courtship activity in autumn; copulation was rarely observed in T. hermanni (only 0.36% of courting males) and not seen in the other species in the field. Observations made throughout the activity season indicated that feeding was equally common in males and females in all three species. Differences in shape were more likely to be the result of sexual selection than of natural selection for fecundity. Detailed predictions are made for sexual dimorphism of other characters in these species.  相似文献   

15.
We examine the evolutionary relationships of the five traditionally recognized species of the western Palearctic tortoise genus Testudo (T. graeca, T. hermanni, T. horsfieldii, T. kleinmanni, and T. marginata) and the newly described dwarfed species T. weissingeri by using sequence data of the mitochondrial cytochrome b gene and nuclear genomic fingerprints with inter-simple sequence repeats (ISSR). Testudo weissingeri differs from T. marginata mainly by its smaller size and some color-pattern characteristics. T. weissingeri lives in the driest, poorest and hottest part of the distributional range of T. marginata. While both data sets demonstrated phylogenetic distinctness of the five traditionally recognized species of Testudo, some subspecies and even some local populations, we detected no differentiation between T. marginata and T. weissingeri. We conclude that T. weissingeri is not a distinct evolutionary unit. We suggest that its small size is the result of suboptimal environmental conditions with limited resources and synonymize it with T. marginata. T. marginata and T. kleinmanni form a clade that is supported both by our mtDNA and nuclear genomic data sets. According to mtDNA data, this clade is the sister taxon to the T. graeca complex. A sister group relationship of T. hermanni and ((T. marginata+T. kleinmanni)+T. graeca) is moderately to weakly supported by mtDNA data; T. horsfieldii is the sister taxon to a clade comprising all other Testudo species.  相似文献   

16.
It has been proposed that plant species cytotypes commonly exhibit altered morphology, reproduction, geographic and ecological distributions. We studied phenotypic variation in height, sexual (flowers, seeds) and asexual (aerial bulbils) reproduction in natural populations and in the conditions of a common garden of three cytotypes (2n = 4x, 5x, 6x) of the bulbous geophyte Allium oleraceum in the Czech Republic. Additionally, we compared the germination and dormancy of seeds and bulbils to determine whether propagules have different ecological roles. The pattern of morphological differentiation observed between cytotypes under natural conditions was similar to that observed under common garden conditions, suggesting that variability in morphological characteristics appears to be associated with ploidy levels. We revealed differences in size and sexual and asexual production between A. oleraceum cytotypes, but with wide overlap among cytotypes, suggesting a limited possibility of the studied traits to reliably distinguish between cytotypes. Tetraploids and pentaploids were rather similar; they were taller and produced more flowers than hexaploids, which were mostly flowerless (mean <0.7 flower/plant). All cytotypes were able to produce viable seeds, but their numbers were extremely low, usually less than 3 seeds per inflorescence; clonal reproduction via aerial bulbils dominates in all cytotypes (flower:bulbil ratio <0.5), with tetraploids producing more but lighter bulbils than other cytotypes. The seed: ovule ratio was low (<0.1) in all cytotypes, although hexaploids reached higher values than other cytotypes. Bulbils germinated better (means >80%) than seeds in all cytotypes, with pentaploid bulbils showing the highest germination (mean 90.5%). The cytotypes did not differ in seed germination (range of means 73.4%–76.3%). About 6% of seeds did not germinate but were still viable at the end of the experiment, while all non-germinated bulbils of all cytotypes had rotten away. Seeds, but not bulbils, can likely form a short-term persistent propagule soil bank. We found no evidence of a phenotypic trade-off between the production of flowers (seeds) and the production of bulbils within the inflorescence of all studied cytotypes. Together, inter-cytotypic differences in fitness-related traits cannot completely explain the different geographic and ecological distributions of cytotypes in the Czech Republic found by previous research.  相似文献   

17.
Polyploid speciation is an important source of angiosperm diversity. Insights into the origin and establishment of new polyploid species may be gained by studying the distributions of ancestral and derivative cytotypes at multiple spatial scales. Diploid (2n = 16) and tetraploid (2n = 32) snow buttercups (Ranunculus adoneus: Ranunculaceae) occur in the alpine of the central and southern Rocky Mountains. Root-tip squashes and flow cytometry were used to determine the ploidy of 1618 individuals from 35 populations. Samples from 31 of the 35 sites were entirely of one cytotype, either diploid or tetraploid. Diploid and tetraploid snow buttercups have nonoverlapping regional distributions. Where both cytotypes occur on the same site, the two are spatially segregated despite no apparent change in habitat. Triploid snow buttercups were only found at a diploid/tetraploid contact zone, while two hexaploid plants were found in tetraploid populations. Tetraploid establishment once or twice in the history of the species complex could account for the regional distribution of the two cytotypes. Habitat differentiation between cytotypes or reproductive exclusion of minority cytotypes may explain the observed segregation at both microgeographic and regional scales.  相似文献   

18.
Analysis of 265 plants derived from 13 sites in the Rokko Mountains shows that the widely distributed eastern AsianEupatorium chinense var.simplicifolium consists of seven cytotypes. These polymorphic karyotypes comprise four levels of ploidy based on X=10 and partial deficiency, occurring either alone or in combination. The polyploid cytotypes exhibit anomalous meiosis and highly variable pollen stainability in contrast to the nearly-normal behaviour of the diploid. The polyploid cytotypes were revealed as being agamospermous. They are readily distinguishable from the diploid cytotypes by several morphological characters and by growth habits closely related to their respective niches. Two or more cytotypes occurred in all sites examined, the most common being the coexistence of triploid and tetraploid cytotypes. The frequencies of occurrence of the pentaploid plants and the cytotypes involving a deficient chromosome were relatively low. While the diploid cytotype is restricted to fragile gravitational slopes and rocky areas which are poor in species and lack tall competitors, the polyploids occur widely in the grasslands, the roadsides or the forest-margins, closely associated with tall grasses and forbs such asMiscanthus sinensis. Based on these data, theE. chinense var.simplicifolium complex is divided into two distinct groups: the diploid cytotype and the polyploid cytotypes.  相似文献   

19.
The blackness and physical appearance of Mediterranean spur-thighed tortoises ( Testudo graeca L.) are recorded in field populations. The inter-relationships between carapace and plastron length, fourth vertebral scute width and other morphometric characters are related to growth. The rear fontanelle is larger in males and the plastron length correspondingly smaller. The relationship between carapace length ( y ) in mm and body mass ( x ) in g is strongly allometric and given by y = 16.63 x 0–34. The maximum carapace lengths recorded for male and female T. graeca graeca L. in NW. Africa are 151 and 198 mm, and for larger T. graeca ibera Pallas in W. Turkey and NE. Greece 208 and 218 mm, respectively. The growth annuli of epidermal scutes are deposited yearly until external growth ceases. The number is used to assess the age of wild animals. Tortoises can be full-grown by 19 years but some, especially slower growing ones, deposit further annuli. The biggest mean growth increments occur up to 7 years with the largest in individuals over the 5–12 year period. The proportion of immature tortoises, adult sex ratios, size and body mass structure, age distribution, annual recruitment and survivorship until full-grown, and abundance (sighting frequency) are compared in northern and southern range populations of NW. African T. g. graeca and S. Anatolian and SE. European (Thrace and Macedonia) ones of T. g. ibera. These are discussed in relation to other tortoise species.  相似文献   

20.
40 population samples of 17 GreekFritillaria species were examined morphologically using 22 attributes carefully selected, with a high discriminating ability. Principal component analysis with a nearest neighbour directed network and cluster analysis were used to evaluate the phenetic similarities among the species. The evidence presented here suggests: (1) A close relationship betweenF. erhartii andF. obliqua and their possible origin fromF. bithynica. (2) A strong alliance betweenF. rixii, F. euboeica, F. carica, andF. drenovskii (groupF. sibthorpiana). (3) A link between theF. epirotica andF. graeca group and some affinities betweenF. pontica, F. gussichiae, andF. graeca. Finally it is proposed thatF. tuntasia be reduced to subspecific status asF. obliqua subsp.tuntasia. This study forms a part of a doctoral dissertation thesis submitted to the Department of Biology of the University of Thessaloniki.  相似文献   

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