The typical black coloured ebony wood (Diospyros, Ebenaceae) is desired as a com- mercial timber because of its durable and aesthetic properties. Surprisingly, a comprehensive wood anatomical... Show moreThe typical black coloured ebony wood (Diospyros, Ebenaceae) is desired as a com- mercial timber because of its durable and aesthetic properties. Surprisingly, a comprehensive wood anatomical overview of the genus is lacking, making it impossible to fully grasp the diversity in microscopic anatomy and to distinguish between CITES protected species native to Madagascar and the rest. We present the largest microscopic wood anatomical reference database for ebony woods and reconstruct evolutionary patterns in the microscopic wood anatomy within the family level using an earlier generated molecular phylogeny. Wood samples from 246 Diospyros species are described based on standardised light microscope observations. For the ancestral state reconstruction, we selected eight wood anatomical characters from 88 Ebenaceae species (including 29 Malagasy Diospyros species) that were included in the most recently reconstructed family phylogeny. Within Diospyros, the localisation of prismatic crystals (either in axial parenchyma or in rays) shows the highest phylogenetic value and appears to have a biogeographical signal. The molecular defined subclade Diospyros clade IX can be clearly distinguished from other ebony woods by its storied structure. Across Ebenaceae, Lissocarpa is distinguishable from the remaining genera by the combined presence of scalariform and simple vessel perforation plates, and Royena typically has silica bodies instead of prismatic crystals. The local deposition of prismatic crystals and the presence of storied structure allow identifying ebony wood species at the subgeneric level, but species-level identification is not possible. In an attempt to improve the identification accuracy of the CITES protected Malagasy woods, we applied computer vision algorithms based on microscopic images from our reference database (microscopic slides from ca. 1000 Diospyros specimens) and performed chemical profiling based on DART TOFMS. Show less
The interplay between evolution and its role in diversification of Nepenthes binds the studies of this thesis. How evolutionary mechanisms and timing relate to molecular divergence and... Show more The interplay between evolution and its role in diversification of Nepenthes binds the studies of this thesis. How evolutionary mechanisms and timing relate to molecular divergence and phylogenetic signal in the genus Nepenthes were investigated. This in conjunction with distribution modeling and mapping anatomical characters – an approach that led to a broad understanding of why and how best to protect specific geographical areas for conservation of Nepenthes. All work was framed with an interdisciplinary approach, each chapter furthering exploration of the connective ties in how past evolutionary history and its impact on diversity helps us to predict future diversity. Show less
Lens, F.P.; Vos, R.A.; Charrier, G.; Niet, T. van der; Merckx, V.S.F.T.; Baas, P.; ... ; Janssens, S.B. 2016
Angiosperms with simple vessel perforations have evolved many times independently of species having scalariform perforations, but detailed studies to understand why these transitions in wood... Show moreAngiosperms with simple vessel perforations have evolved many times independently of species having scalariform perforations, but detailed studies to understand why these transitions in wood evolution have happened are lacking. We focus on the striking difference in wood anatomy between two closely related genera of Adoxaceae, Viburnum and Sambucus, and link the anatomical divergence with climatic and physiological insights. After performing wood anatomical observations, we used a molecular phylogenetic framework to estimate divergence times for 127 Adoxaceae species. The conditions under which the genera diversified were estimated using ancestral area reconstruction and optimization of ancestral climates, and xylem-specific conductivity measurements were performed. Viburnum, characterized by scalariform vessel perforations (ancestral), diversified earlier than Sambucus, having simple perforations (derived). Ancestral climate reconstruction analyses point to cold temperate preference for Viburnum and warm temperate for Sambucus. This is reflected in the xylem-specific conductivity rates of the co-occurring species investigated, showing that Viburnum lantana has rates much lower than Sambucus nigra. The lack of selective pressure for high conductive efficiency during early diversification of Viburnum and the potentially adaptive value of scalariform perforations in frost-prone cold temperate climates have led to retention of the ancestral vessel perforation type, while higher temperatures during early diversification of Sambucus have triggered the evolution of simple vessel perforations, allowing more efficient long-distance water transport. Show less
