TY - JOUR T1 - Die Knospe als Organ und Verlauf der Formenreihen-Bildung. Herbsttagung «Evolving Morphology» A1 - Studer, Kathrin JA - Elem. d. Naturw. JF - Elemente der Naturwissenschaft PY - 2018 VL - 108 SP - 101 EP - 122 DO - 10.18756/edn.108.101 SN - p-ISSN 0422-9630 LA - de N2 -

In der Blattfolge einjähriger Kräuter verändert sich die Form der einzelnen Seitenorgane in gesetzmässiger Weise. Diese Organe werden differenziert und meist anschliessend direkt entfaltet. Dieser Artikel zeigt an einigen Beispielen, dass auch laubwerfende Gehölze eine sonst in der Knospe verborgene Blattreihe mit einem gesetzmässigen Verlauf der Formveränderung haben. Die Untersuchung der primären Morphogenese einzelner Knospenorgane zeigt die tatsächliche Bildung der unterschiedlichen Formen, das Werden der Formenreihen, sowie auch dessen zeitliche Einbettung im Jahreslauf. Die Beobachtung der Seitenorgan-Bildung während des Jahres ermöglicht Darstellung und Verständnis des Übergangs von Laubblättern zu Knospenschuppen, aber auch von Knospenschuppen wieder zu Laubblättern von Gehölzen. Indem dieser Wechsel einerseits mit dem Übergang vom Laubblatt- in den Blütenbereich, andererseits mit dem Austreiben aus Winterknospen von krautigen Pflanzen in Beziehung gesetzt wird, zeigt sich dieser Übergang als weiterer empirischer Beleg für eine These zu entwicklungsgeschichtlichen Zusammenhängen, die bislang nicht so breit fundiert war.

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In the leaf-sequence of annual herbs the form of the lateral organs along the shoot changes following a pattern. These organs differentiate and then unfold almost immediately. This article presents for several decideous bosk-species the sequences of lateral organs, in which a similar pattern can be observed, hidden in the buds. The investigation of primary morphogenesis of single bud organs reveals the building of different forms, the becoming of the whole form-sequence as well as its temporal position in the course of the year. In woody plants, the detailed observation of the differentiation and unfolding of lateral organs during the year elucidates the temporal and spatial aspects of the transition from foliar leaves to bud scales and back to foliar leaves, again. This transition is related to the changeover from the zone of foliar leaves to that of flower organs and the zone from the winter budscales to that of foliar leaves, respectively, along the shoot of herbaceous perennial plants. The similarity of these transition zones is seen as an empirical evidence for a thesis of evolutionary connections between woody and herbaceous flowering plants (Angiosperms), a thesis which - until now - has not been so well-founded.
 

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In the leaf-sequence of annual herbs the form of the lateral organs along the shoot changes following a pattern. These organs differentiate and then unfold almost immediately. This article presents for several decideous bosk-species the sequences of lateral organs, in which a similar pattern can be observed, hidden in the buds. The investigation of primary morphogenesis of single bud organs reveals the building of different forms, the becoming of the whole form-sequence as well as its temporal position in the course of the year. In woody plants, the detailed observation of the differentiation and unfolding of lateral organs during the year elucidates the temporal and spatial aspects of the transition from foliar leaves to bud scales and back to foliar leaves, again. This transition is related to the changeover from the zone of foliar leaves to that of flower organs and the zone from the winter budscales to that of foliar leaves, respectively, along the shoot of herbaceous perennial plants. The similarity of these transition zones is seen as an empirical evidence for a thesis of evolutionary connections between woody and herbaceous flowering plants (Angiosperms), a thesis which - until now - has not been so well-founded.
 

ST - Die Knospe als Organ und Verlauf der Formenreihen-Bildung UR - https://dx.doi.org/10.18756/edn.108.101 Y2 - 2024-04-20 07:11:22 ER -