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Wyświetlanie 1-2 z 2
Tytuł:
Pollination and floral biology of Adonis vernalis L. (Ranunculaceae) - a case study of threatened species
Autorzy:
Denisow, B.
Wrzesien, M.
Cwener, A.
Powiązania:
https://bibliotekanauki.pl/articles/58993.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
pollination
floral biology
pollen viability
seed
Adonis vernalis
Ranunculaceae
threatened species
Opis:
Although the knowledge of pollination systems of rare and threatened species is one of the principles for development of optimal conservation and management strategies, the data about their pollination requirements are scarce or incomplete. Different problems are listed (xerothermic habitat disappearance, overgrowing of patches, plant biology i.e., slow plant growth, problems with seed germination) among the possible causes of Adonis vernalis being threatened, but until now no consideration was given to the flowering biology and pollination. The observations of flowering biology of A. vernalis (Ranunculaceae), a clonal species, were conducted in an out-ofcompact- range population, in the Lublin Upland, Poland (51°18'55" N, 22°38'21" E), in 2011–2013. The reproductive potential of A. vernalis is related to the population age structure, pollination syndrome, and breeding system. The flowers exhibit incomplete protogyny. The dichogamy function is supported by different (biological, morphological) mechanisms. Stigma receptivity occurred about one day before anthers started shedding self-pollen, and pollen viability was increasing gradually during the flower life-span (66.3% in distal anthers vs. 77.3% in proximal). The decrease in pollen production and in pollen viability coincided with the lowest degree of seed set, irrespective of the pollination treatment. Pollen vectors are necessary for efficient pollination, as the proportion of pistils setting fruits after open pollination (41–82.1%) was significantly higher compared to spontaneous self-pollination (only 5.5–12.3%). The pollination requirements together with pollen/ovule ratio (P/O = 501) indicate a facultative xenogamous breeding system in A. vernalis. Therefore, in the conditions of the global lack of pollinators, improper pollination may weaken the population by leading to a decrease in the proportion of recombinants, and in addition to other factors, may accelerate extinction of small A. vernalis populations.
Źródło:
Acta Societatis Botanicorum Poloniae; 2014, 83, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Does vegetation impact on the population dynamics and male function in Anemone sylvestris L. (Ranunculaceae)? A case study in three natural populations of xerothermic grasslands
Autorzy:
Denisow, B.
Wrzesien, M.
Powiązania:
https://bibliotekanauki.pl/articles/57860.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
vegetation impact
population dynamics
male
function
Anemone sylvestris
Ranunculaceae
natural population
xerothermic grassland
rare species
shrub
plant expansion
pollen mass
pollen viability
seed set
Opis:
In Poland, like in other parts of Central Europe, dry grasslands significantly contribute to the biodiversity of both fauna and flora. Anthropogenic pressure impair many species of xerothermic habitats, and several populations face an increased risk of extinction. The goal of the study was to define factors that may affect the size of wild populations of Anemone sylvestris L., a protected species in Poland, with both a short- and long-term perspective, and to examine the influence of vegetation changes on the density, the abundance of flowering and male function (pollen production, pollen viability), as well as seed set. In situ observations were performed in 2005-2006 and 2011-2012 in three populations located on the Lublin Upland, SE Poland. The reduction in population density and A. sylvestris blooming was exacerbated by the expansion of the shrubs, but not by Brachypodium pinnatum. Male characteristics of A. sylvestris, i.e. pollen amount per multi-staminate flowers or pollen viability appeared to decrease under pressure of shrub competition. Populations with limitation of male function had impaired degree of seed set. Various consequences for the functioning of populations within a metapopulation system can be expected due to substantial qualitative and quantitative disorders in pollen traits. It is crucial that successful recovery programs for A. sylvestris primary should aim to conserve and manage the habitat.
Źródło:
Acta Societatis Botanicorum Poloniae; 2015, 84, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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