Equatorial Aperture Pattern in Monocots: Same Definition Rules as in Eudicots? The Example of Two Species of Pontederiaceae

Pontederia cordata L. and Eichhornia paniculata (Spreng.) Solms (Pontederiaceae, monocots) produce disulculate pollen grains. The formation of intersporal callose walls was followed in these two species by staining callose during male meiosis. A new type of cytokinesis that ends with the formation of conspicuous callose knobs at future aperture sites was observed. This observation indicates that the formation of the disulculate pattern is linked to cytokinesis. Thus, equatorial aperture patterns of monocots and aperture patterns of eudicots appear to be defined by similar mechanisms.