Abstract
In 32 Geraniaceae species, we investigated the so-called light line in the palisade layer of the seed coat. The light line is an incrustation of electron-dense substances in the secondary cell wall. The existence of different gaps in the line and its complete absence near the chalazal area suggest that this cell wall structure is not responsible for hardseededness in the Geraniaceae seed coat. The multiple light line pattern within idioblasts of the palisade layer is characteristic of this cell type, named multiple light line (mll) cells. The palisade cells and their light line in Geraniaceae differ structurally from those in the Fabaceae.
Key words
Light line - seed coat - hardseededness - seed coat impermeability - palisade layer - secondary cell wall development - Geraniaceae
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A. Meisert
Department of Biology
University of Hildesheim
Marienburger Platz 22
31141 Hildesheim
Germany
Email: meisert@rz.uni-hildesheim.de
Section Editor: A. M. C. Emons
