Phänologie, Bestäubung und Reproduktionsbiologie von Asteroideae (Asteraceae) in unterschiedlichen Höhenstufen Süddeutschlands
Auch gedruckt in der BibliothekZ: J-H 10.908 ; W: W-H 8.857
FakultätFakultät für Naturwissenschaften
Ressourcen- / MedientypDissertation, Text
Datum der Freischaltung2005-11-30
Written studies on the biology of pollination and reproduction are not often covered in any great detail. In only a few cases do they distinguish between particular features of the different species. In this study seven species of five genera of the family Asteraceae were studied at different altitudes in Southern Germany. The phenology as well as morphologically criteria and parameter such as pollination and reproduction were determined. The aim of this study was to compare and distinguish between various attributes of the studied species and to establish any links based upon geographical locations. In addition a clarification of syndromes of pollination was carried out and the limiting factors in generative reproduction were determined. This study showed further insight into the biology of pollination and reproduction of some species of Asteroideae. For the first time it was possible to give a conclusion about the attraction of ray and disc florets of these species. Respectively all florets where removed. This procedure also led to the clarification of ray florets fertility and the differentiation about this feature within the studied species. Obervations on the disc florets of Bellis perennis point towards the pronation of the style branches leading to the hypothesis that pollen must be gently pushed in between the stigmatic cord onto receptive parts. Therefore an effective pollination by tiny insects is doubtful. This implicates that every single flower visitor, exhibiting a certain weight, in fact is a potential pollinator on this entomophilous species. This study concludes that further experimental examinations of these species are auspicious because new and interesting aspects may be discovered within the biology of reproduction of these plants.
LizenzStandard (Fassung vom 03.05.2003)