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In contrast to other natural objects situated within boundaries of the city of Poznań, the former ecological site "Bogdanka" distinguishes itself by its exceptional floristic values. The flora of this object comprises 527 taxons of vascular plants derived from 91 families and 295 genera, of which 180 can be found on rare and threatened species lists. In addition, 15 species under legal protection as well as 34 species from all country and regional lists of rare and endangered species occur here. The most valuable floristic elements include: Iris sibirica, Galium odoratum, Hierohloë odorata, Trollius europaeus or Dianthus superbus. Several trees with monumental or close to monumental circumferences as well as splendid trees can also be found in this site. The area should regain its protected status as soon as possible.
The morphology of pollen grains of 16 species from the Rosa L. genus were studied (i.e. R. agrestis, R. canina, R. dumalis, R. gallica, R. inodora, R. jundzillii, R. kostrakiewiczii, R. majalis, R. micrantha, R. mollis, R. pendulina, R. rubiginosa, R. sherardii, R. tomentosa, R. villosa, and R. zalana). The material came from 16 native localities of those species in Poland. The measurements are based on at least 30-50 randomly selected, fully developed pollen grains per specimen. In total, 500 pollen grains were examined. They were analysed for 13 quantitative features of pollen grains and exine sculpturing and the following qualitative traits: outline, shape, "operculum" structure. The diagnostic features of pollen grains of studied species were: length of polar and equatorial axes and length of ectocolpi. The above-mentioned pollen grain morphological features make isolation of one species possible: R. gallica. R. gallica is distinguished for its highest values of the length of polar and equatorial axes, and the length of ectocolpi. The obtained analytical results of operculum and exine sculpture features, considered as diagnostic, corroborated only slightly their priority significance for the isolation of the examined species and sections. The collected data failed to confirm fully the current taxonomical division of the Rosa genus into sections (only section Gallicanae from R. gallica is isolated) as well as consanguinity relationships between the examined species from the Caninae section. On the dendrogram, both species closely related with each other as well as those from other developmental lines were found in the same group. These equivocal results are by no means surprising because the Caninae section is the most polymorphic group in the Rosa genus, and contemporary Caninae are of the nature of a swarm of R. canina hybrids as a link combining all taxons of the section.
The inventory carried out in the 19th century historic park in Swadzim near Poznań recorded the total of 1886 trees, bushes and climbers deriving from 64 species. At the present time, the park is neglected and a plan for its revalorization is badly needed. Tree composition is dominated by Quercus robur, Robinia pseudoacacia, Acer pseudoplatanus, Carpinus betulus, Q. rubra and Fagus sylvatica, while that of bushes – by Sambucus nigra. The height of trees ranges from 16 to 20 m and their circumferences – from 45 to 114 cm; the health condition of the majority of trees is good or even very good. Single specimens of rare and threatened species were found to occur. The total of 101 splendid trees from 26 taxons were inventoried among which A. pseudoplatanus, A. platanoides, Aesculus hippocastanum, R. pseudoacacia and C. betulus dominated. In comparison with the Rataj’s inventory from 1976, transformations are apparent in the dendroflora of the park towards its naturalisation. The tree stand requires cutting and tending intervention.
The variability of pollen grains of 16 species from genus Rosa L. was studied (i.e. Rosa agrestis, R. canina, R. dumalis, R. gallica, R. inodora, R. jundzillii, R. kostrakiewiczii, R. majalis, R. micrantha, R. mollis, R. pendulina, R. rubiginosa, R. sherardii, R. tomentosa, R. villosa, and R. zalana). The material came from 107 native localities of those species in Poland. The measurements are based on at least 30–50 randomly selected mature pollen grains per specimen. In total, 3510 pollen grains were examined. They were analysed for 8 quantitative features, i.e. length of polar axis (P), length of equatorial axis (E), exine thickness on the pole (Exp), exine thickness at the equator plane (Exe), length of ectocolpi (Le), P/E ratio, and relative thickness of exine (Exp/P and Exe/E ratio). Statistically significant differences were found among the examined species with regard to all analysed pollen features. The pollen and ectocolpi dimensions (P, E and Le) were largest in R.gallica (35.9, 28.1, and 28.0 μm, respectively) and smallest in R. majalis (27.0, 20.2, and 21.2 μm, respectively). The mean coefficients of variability of the pollen features measured can be used to arrange the examined rose species from the least to the most variable as follows: R. pendulina, R. villosa, R. jundzillii, R. inodora, R. canina, R. rubiginosa, R. dumalis, R. gallica, R. agrestis , R. micrantha, R. zalana, R. tomentosa, R. sherardii, R. majalis, R. kostrakiewiczii and R. mollis. The obtained data failed to confirm fully both the division of the Rosa genus currently in force in taxonomy into sections as well as relationships among the examined species from the Caninae section. In addition, values of morphological characters of the same species may differ considerably from one another. The extent of these differences indicated that it was necessary to measure large numbers of pollen grains in order to obtain accurate biometric data.
Dendroflora of Złakowo Park comprises 36 taxons. The total of 1465 trees was inventoried. The dominant tree species in the park are those associated with the communities of fertile broad-leaved forests. Trees of Carpinus betulus are the most numerous, whereas common species include: Fagus sylvatica, Fraxinus excelsior and Quercus robur. The total of 203 trees was classified as valuable of which 77 trees were included in the group with monumental circumferences, 35 trees – were classified as trees with circumferences close to monumental and 91 trees – as splendid. Trees which frequently attained considerable circumferences comprised: Carpinus betulus, Quercus robur, Fagus sylvatica, Alnus glutinosa, Fraxinus excelsior and Acer platanoides.
The objective of this study was to investigate the ranges of intra- and interindividual variability on the example of R. canina. For this purpose, four flowers were collected randomly (72 flowers in total)from 18 wild shrubs of R. canina growing in one population in Poznań (Poland)and then, from each flower, 50 correctly formed pollen grains (200 pollen grains per each individual)were selected. Inter- and intraindividual pollen grain variability was characterised based on 3600 pollen grains. They were analysed for seven quantitative features, i.e. length of polar axis (P), equatorial diameter (E), thickness of the exine along the polar axis (Exp), length of ectocolpi (Le) and P/E, Exp/P, and Le/P ratios. Our study revealed highly significant differences among flowers of the particular R. canina individuals with respect to all pollen grain biometrical features. In addition, it showed that the assessment of the full range of variability in pollen grain biometric features within one individual (shrub)was more reliable if we examined several pollen grains from several flowers than for the same number of pollen grains derived from a single flower. We also found statistically significant differences among particular individuals in all pollen grain features. This proves that in order to well characterise a population of a given species from the point of view of palynology, the plant material should derive from a possibly numerous number of individuals (shrubs).
The main aim of the study was to determine which of the viability and germination capacity of pollen grains estimation methods are optimal and to test if the studied sections and species within the Rosa genus are differentiated in pollen viability andgermination capacity. We analysedandcomparedpollen grains of 14 wild Rosa species using 5 viability tests and13 various liquidandagar media. Viability of pollen grains in the majority of the examinedspecies was greater than their germination capacity. The most viable pollen grains were foundin R. gallica (section Gallicanae), where average of 5 viability tests is 90.69%, andin R. pendulina (section Rosa) – 86.85%. Species from section Caninae have a lower level of viability (from 60.59% in R. rubiginosa to 31.23% in R. inodora). Pollen of species from sections Gallicanae (R. gallica; to 63.4%) and Rosa (R. pendulina; to 47.21%) germinatedmuch better than the pollen of the majority of species from section Caninae (with the exception of R. zalana; to 47.22%). The examinedpollen grains germinatedmost numerously on agar medium with 1.5% agar+15% sucrose+50 ppm boric acidandliquidmed ium with 15% sucrose+ 50 ppm boric acid. Following deep-freeze storage (–25°C) for six months, the pollen grains of nine selected species (with the exception of R. rubiginosa) showed viability higher or similar to that before storage.
The total of 35 splendid pear trees was inventoried in the Citadel Park and they constitute approximately 13% of the most valuable trees in this park. The circumferences of the measured trees ranged from 150 to 264 cm. Considerable circumferences were determined in the case of 32 pear trees, of which 11 trees had monumental circumferences and 21 specimens – close to monumental circumferences. From among 14 trees found to be in a very good health condition and having monumental or close to monumental circumferences, “candidates” for legal protection in the form of nature monuments should be selected.
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