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Small-scale spatial pattern of two common European geophytes Allium oleraceum and A. vineale in contrasting habitats

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The small-scale spatial patterns in Allium oleraceum L. and A. vineale L. populations, both common European geophytes, were studied in four contrasting habitats (meadow, scree, scrub and forest). Coefficient of dispersion indicated marked clumped distribution of the individuals of both species in all habitats. Pattern analysis revealed considerable differences in pattern both between species studied and among populations of respective species studied. The analyses clearly point at two distinct morphological features of both species concerning dispersion, which affect pattern of their populations - formation of daughter bulbs and that of aerial bulbils. Existence of 'morphological' patches at low block size was a common feature of all A. vineale populations studied regardless of habitat; the patchiness was caused by frequent production of many daughter bulbs in close neighbourhood of the parent plant. In contrast, variable and almost no remarkable small 'morphological' patches of A. oleraceum, corresponding to clumps of plants originated from daughter bulbs, were detected since daughter bulbs were frequently produced above ground and thus embodied a potential to disperse to the longer distance from the parent plant. Cluster dispersion of bulbils and their restricted dispersal distances were responsible for occurrence of small patches and second-order patches in most populations of both species.
... A similar pattern of bulblet development, resulting in the clustered spatial pattern of individuals, has been observed in some other polyploid Allium species of A. sect. Codonoprasum (e.g. A. oleraceum L.;Duchoslav, 2001, Duchoslav et al., 2010 and sect. Allium (e.g. A. vineale L.; Håkansson, 1963;Duchoslav, 2001). ...
... Codonoprasum (e.g. A. oleraceum L.;Duchoslav, 2001, Duchoslav et al., 2010 and sect. Allium (e.g. A. vineale L.; Håkansson, 1963;Duchoslav, 2001). The flowering period lasted from mid-August to the end of September. ...
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Allium sect. Codonoprasum represents an evolutionarily young and rapidly radiating group of bulbous geophytes, with a significant proportion of polyploids and minor morphological differences between species. In the last 20 years, dozens of new species have been described from the Mediterranean. However, very little new information has been obtained on most of them since their description, especially in terms of cytogenetic, molecular and distribution data. Allium goumenissanum is a recently described species of this section, known only from three nearby localities in northern Greece. During the last 10 years, we collected population samples of an unknown species of this section from the southern Balkans, which seemed to be representative of A. goumenissanum. A variety of methods (cytogenetic, molecular, morphological and micromorphological) were used to compare the populations of an unknown species with the morphologically similar species A. goumenissanum and A. stamatiadae. AFLP, ITS sequencing and genome size analyses showed that all populations of the unknown species were in fact A. goumenissanum distinct from A. stamatiadae. The characterization of the morphology and reproduction of A. goumenissanum is completed, and micromorphological and anatomical characteristics of the leaves of both species are newly published. The distribution of A. goumenissanum, based on new data, now includes a more extensive area of north central Greece, and the species is found as a new taxon for Bulgaria.
... In Central Europe, Allium oleraceum is a typical species of the vegetation class Festuco-Brometea, which occurs on calcium rich soil (Ellenberg et al. 1991). In the Czech Republik, Allium oleraceum frequently occurs in deciduous woods, especially in oak-hornbeam woodland of the Carpinion alliance (Duchoslav 2001a(Duchoslav , 2001b. Passarge (1985) described the Gagea pratensis -Allium oleraceum association from northern Germany. ...
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The distribution of the field garlic, Allium oleraceum L., in Finland is presented according to herbaria voucher specimens, literature and field observations of the authors. The habitats of A. oleraceum, rock and dry meadows, mesic meadows, gardens and a few deciduous stands, are shortly described. The habitats are mostly influenced by man and domestic animals. The species is often found on iron age mounds, in ancient hilltop fortresses and in areas with medieval settlement, e.g. in connection with medieval castles and churches. A. oleraceum is moderately calciphilic as it is much more common in areas with calcareous bedrock or soil than in acid areas. The accompanying vascular plant flora is briefly presented.
... V terénu lze jeho populace dobøe identifikovat na jaøe (bøezen-duben), kdy na lokalitách bez vlivu podzemní disturbance, tedy nejèastìji na zastínìných stanovištích, ale i na kosených èi pasených lokalitách, vytváøí nápadné trsy o prùmìru do maximálnì 15 cm èítající desítky a stovky vìtšinou sterilních jedincù (Duchoslav 2001b). Trsy pøipomínají trsy pa itky a èasto takto bývají i mylnì identifikovány. ...
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The distribution and habitat conditions of two taxa of the genus Allium sect. Allium (Allium sphaerocephalon, Allium vineale) were studied on the territory of the Czech Republic. Allium sphaerocephalon is a rare species which inhabits two types of habitat: thermophilous, perennial vegetation of rock outcrops (Alysso-Festucion pallentis alliance) and continental steppe vegetation (Festucion valesiacae alliance), in the warmest and driest areas of both Bohemia (northern part of Central Bohemia and North Bohemia) and Moravia (SouthMoravia) at lower altitudes (150–550 m a.s.l.) with most localities found below 400 m a.s.l. The species is included in the Red List of vascular plants of the Czech Republic. In contrast, Allium vineale is a common species occurring from the lowlands up to montane belt (128–850 m a.s.l.) with most localities found between 200 and 500 m a.s.l. The species inhabits a wide spectrum of habitats ranging from arable fields and vineyards (mostly in the past, presently seldom), field margins and road embankments (common), through mesic pastures (Cynosurion alliance) and meadows (Arrhenatherion alliance), disturbed broad-leaved dry grasslands (Bromion and Cirsio-Brachypodion alliances), and grassland vegetation on sandy soils, to scrub and rarely also mesic forests (Carpinion alliance) and floodplain forests (Alnion incanae alliance).
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Clonal plants are, on average, considered to be as genetically diverse as nonclonal plants. However, the behaviour of clonal plants ranges between multiclonality and uniclonality, depending on environmental conditions and life history traits. Allozyme electrophoresis of band phenotypes was used to examine the genetic structure of 13 cytotype-uniform and 17 cytotype-mixed populations of polyploid Allium oleraceum (2n = 4x, 5x, 6x), a clonal bulbous geophyte that has been considered seed-sterile and completely reliant on vegetative reproduction through aerial bulbils and daughter bulbs. The genetic structure was dominated by low within-population variation whereas genetic differentiation was high among populations. Eighty-five distinct multilocus genotypes were found among 756 sampled individuals, but populations generally exhibited a low level of clonal diversity. Tetra- and pentaploids showed twofold higher total and within-population diversities, but also had more genetically differentiated populations in comparison with hexaploids. Tetraploids formed two separate groups in the cluster analysis, and this finding most likely suggests their different origin. Pentaploids were clustered in a separate cluster and frequently intermixed with tetra- and hexaploids sampled at cytotype-mixed sites. Such a pattern suggests gene flow between cytotypes. Most hexaploids were genetically similar and clustered separately from the other cytotypes, suggesting their similar origin and absence of gene flow to and from other cytotypes. Identical band phenotypes found in coexisting cytotypes within certain mixed-ploidy populations might indicate in situ neopolyploidization. Collectively, the pattern of genetic structure and diversity observed in A. oleraceum is typical of clonal plants with the dominance of vegetative offspring and scarce recruitment of sexual offspring. The low and spatially unstructured genetic variation observed in hexaploids, in contrast with higher and spatially structured genetic variation in tetra- and pentaploids, seems to be related to different levels of sexual fertility, ecological amplitude and colonization abilities of the cytotypes. It provides evidence for the existence of both primary and secondary contact zones of cytotypes in A. oleraceum.
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The distribution and habitat differentiation of Allium oleraceum L. and Allium vineale L. in the Czech Republic based on herbarium material is reported. Both species are documented from the rather large number of localities all over the Czech Republic and do not show apparent large-scale pattern of distribution except of their frequent absence in mountain regions. The altitudinal range of both species in the Czech Republic is very similar. Both species are concentrated from the colline to submontane belts (200 – 600 m) but rarely also occur in the montane belt, especially in the case of A. oleraceum. Both species occur in wide range of habitats ranging from rocks and arable fields to forests. Nevertheless, their relative frequencies within respective habitats significantly differ. A. oleraceum occurs as common species in forests (esp. in oak-hornbeam forests) and forest edges, on rocks, at field margins, on sunny slopes and in steppe communities. On the other hand, A. vineale is common in arable fields (esp. in the past), on field margins, roadsides, in ditch-banks and in meadows while it is rarely found on rocks, in forests and shrub. Distribution and habitat differentiation of both species in the Czech Republic are compared with data from other parts of their distribution area. The species’ habitat differentiation is briefly discussed from the point of view of plant traits.
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... Levan (1938) considered A. oleraceum to be an autopolyploid form of diploid Allium paniculatum that arose by somatic doubling of the chromosomes, although he did not rule out fusion of unreduced gametes as an alternative. ...
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The spatial distribution of cytotypes can provide valuable insights into the evolution of polyploid complexes. Previously, only tetraploid Allium oleraceum was reported from Slovakia. Analysing 863 individuals from 93 populations from Slovakia revealed an extensive variation in theDNAploidy levels of Allium oleraceum (3x, 4x, 5x and 6x). Of the main cytotypes, the penta- and tetraploids had strongly overlapping distributions, although the pentaploids exhibited a tendency to occur more frequently in the southern and the tetraploids had a tendency to occur in the northern regions of Slovakia. A triploid cytotype was found in one population in the southern part of Slovakia, which is the third locality worldwide for this cytotype. The hexaploid cytotype was rare and sparsely occurred in western and southern Slovakia. Sixteen per cent of the populations sampled consisted of more than one ploidy level; the most common was a combination of penta- and tetraploids. The cytotypes differed with respect to altitude; the tetraploids were found significantly more frequently at higher altitudes than the penta- and hexaploids. When compared with reanalysed altitudinal distribution data from the Czech Republic divided into two geographic areas (Carpathian and Herzynian) the pattern found in the Carpathian part of the Czech Republic was similar to that in Slovakia, with tetraploids at the higher altitudes. The distribution in the Herzynian part (Bohemian Massif) was just the opposite: the tetraploids were more often found at lower altitudes than the penta- and hexaploids. Both tetra- and pentaploid cytotypes occurred in a wide and similar spectrum of habitats, while hexaploids were limited to human-influenced habitats. A local-scale distribution of cytotypes analysed in detail in the Slovak Karst area, showed surprising differences in the distribution of cytotypes on particular karst plains, which can be related to different land uses. Concerning the contrasting altitudinal differentiation of tetraploids in the regions compared, the results suggest that at least two different types of tetraploids occur in Central Europe. The apparent cytotype diversity in the surrounding Slovak Karst area may suggest the existence of a primary contact zone.
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Allium vineale and A. oleraceum are two related bulbous geophytes with an annual storage organ that coexist in a wide range of habitats but show both partly different geographic ranges and habitat preferences in Europe. To explore whether ecological and distributional differences between species can be related to expected variation in some key life-history traits between them, research was undertaken to compare the phenology, seasonal growth, and dry-mass allocation of vegetative and reproductive plants of the species at successional gradient comprising three sites with contrasting environmental conditions (steppe, scrub, forest), where populations of the study species coexist (the Czech Republic). The results showed, in general, partly different timing of phenophases between species and different responses of species to contrasting environmental conditions. A. vineale displayed an annual life cycle similar to that observed in many Mediterranean geophytes, i.e. regularly sprouting above ground before the arrival of winter, its growth was concentrated into early and mid-spring and started to wither after a temperature increase and several short-term drought events in early summer, though its flow- ering was delayed until late June. A. oleraceum showed high year-on-year variation in the onset of shoot elongation above-ground; its growth was concentrated into mid- and late spring and its flowering was delayed until July. The patterns of phenology observed between the study species thus partly reflect selection under different environmental conditions of their origin. The total duration of the green above-ground period of reproductive plants in both species continued about 1.5–2 months beyond that of the vegetative ones. Over main growth period, mean relative growth rates (RGR) of A. oleraceum and A. vineale ranged from 20 to 22 and from 6 to 28 mg g–1dw day–1, respectively. A. vineale showed significantly higher RGR than A. oleraceum only in steppe conditions while at shaded sites the re- verse pattern was found. The RGR of both veg- etative and reproductive plants of A. oleraceum did not differ from one site to another. On the other hand, both vegetative and reproductive A. vineale plants showed lower RGR at shaded sites than at steppe one. Shading increased allocation into leaves in both species, caused complete abortion of developing scapes in A. vineale but only reduced reproductive allocation in A. olera- ceum. A. oleraceum was able to maintain fitness- related traits more stably across the environments studied than A. vineale that fit well into the pattern of habitat differentiation observed between them in Central Europe. Data concerning growth of and allocation into new bulb in both species also support the hypothesis that allocating reserves for the coming year is the first priority in geophytes with an annual storage organ.
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Experimental studies that explore the possible causes of ploidy distributions and niche differentiation are rare. Increased competitive ability may be advantageous for survival in dense vegetation and may strongly affect local and regional abundances of cytotypes and potentially contribute to invasion success. We compared survival, growth and reproduction of plants originating from bulbils of three cytotypes (2n = 4x, 5x, 6x) of Allium oleraceum growing with and without a competitor (Arrhenatherum elatius). There was a strong negative effect of competition but no effect of ploidy or ploidy × competition on survivorship, height and total dry mass of A. oleraceum, i.e. no support for different competitive abilities of the ploidy levels. However, slightly different responses of populations to competition treatments within all cytotypes suggest differentiation within cytotypes. Under competition, plant survivorship was low, surviving plants were small, had low dry mass and produced neither sexual nor asexual propagules. Without competition, plant survivorship was high, and cytotypes differed in three traits after 2 year's growth: dry mass of flowers, number of flowers and ratio of the dry mass of sexual to asexual propagules all decreased with increasing ploidy level. We additionally tested tetra- and pentaploids as to whether plants originating from different types of propagule (bulbils, seeds) differ in survivorship, growth and reproduction when growing with and without a competitor. Plants originating from bulbils had higher survivorship, were more robust, flowered earlier and produced more propagules when compared to plants originating from seeds and grown without competition. Under competition, differences in performance between plants originating from seeds and bulbils mostly disappeared, with higher survivorship only for plants originating from bulbils.
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The ecological characteristics of two propagule types of Allium vineale (sexually produced seeds and asexually produced bulbils) were studied to identify factors which could lead to the maintenance of both propagule types as reproductive mechanisms. Ecological traits studied were dispersal patterns, predation rates and longevity of propagules. Seeds and bulbils dispersed to the same average distance from the parent, but seeds occasionally traveled 10-30 cm further than bulbils. In addition, some bulbil infructescences were observed dispersing as a unit. Predation rates were significantly higher for seeds, but the density of propagules in an area had no effect on removal rates. Seeds and bulbils buried in the field were no longer viable after 1 yr. However, seeds stored in the laboratory for up to 3 yr had higher viability percentages than bulbils. Overall, the ecological differences found between seeds and bulbils are small relative to the differences found among dimorphic propagules of other species, and do not fit the predictions of models for the conditions necessary to maintain the production of heteromorphic propagules.
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1. Two experiments were carried out in an ancient English deciduous woodland to determine the relationship between the occurrence of gaps - unoccupied spaces - in the ground layer and the ability of Narcissus pseudonarcissus to occupy them. In the first experiment, seeds and bulbs of Narcissus were planted into gaps and their fates were followed for 10 years. A second experiment examined the survivorship, mortality, clonal growth and flowering of bulbs and seeds grown in pots at different densities in open and shaded sites. 2. In the first experiment, bulbs planted into gaps in a shaded site performed similarly to controls (naturally established individuals). Plants growing from seeds or seedlings died, as did the controls. It is concluded that the existence and persistence of gaps is a function of the demography of the species rather than of an inherently inimical environment. 3. In the second experiment, survivorship of established bulbs showed a more-or-less constant probability of death, whilst that of seedlings showed declining probability of mortality. Clonal growth rate was density-dependent but establishment of plants from seed was not. Mortality was density-independent, except at high density in open ground. Clonal growth was twice as fast in open ground as in shaded sites. 4. The results of these experiments are brought together in a scheme suggesting that a wide range of densities of N. pseudonarcissus is possible at the site due to the changing balance between reproduction and mortality in a periodically disturbed environment. The implications of this conclusion are explored in relation to ground occupancy and the development of mixtures in the ground flora of ancient British woodlands.