successive cambia a developmental oddity or an adaptive structure连续形成层发育古怪或自适应结构.pdf

Successive Cambia: A Developmental Oddity or an Adaptive Structure? 1,2 1,2 2,3 1 1 Elisabeth M. R. Robert *, Nele Schmitz , Ilse Boeren , Tess Driessens , Kristof Herremans , Johan De 4 5,6 2 1 Mey , Elke Van de Casteele , Hans Beeckman , Nico Koedam 1 Laboratory for Plant Biology and Nature Management (APNA), Vrije Universiteit Brussel (VUB), Brussels, Belgium, 2 Laboratory for Wood Biology and Xylarium, Royal Museum for Central Africa (RMCA), Tervuren, Belgium, 3 Institute of Botany (210), University of Stuttgart-Hohenheim, Stuttgart, Germany, 4 Radiology, Universitair Ziekenhuis Brussel, Brussels, Belgium, 5 SkyScan NV, Kontich, Belgium, 6 Vision Lab, Universiteit Antwerpen (UA), Wilrijk, Belgium Abstract Background: Secondary growth by successive cambia is a rare phenomenon in woody plant species. Only few plant species, within different phylogenetic clades, have secondary growth by more than one vascular cambium. Often, these successive cambia are organised concentrically. In the mangrove genus Avicennia however, the successive cambia seem to have a more complex organisation. This study aimed (i) at understanding the development of successive cambia by giving a three- dimensional description of the hydraulic architecture of Avicennia and (ii) at unveiling the possible adaptive nature of growth by successive cambia through a study of the ecological distribution of plant species with concentric internal phloem. Results: Avicennia had a complex network