A new technique of examining pollen-connecting threads

A new technique of obtaining high resolution structural information on pollen-connecting threads is outlined. The method employs a transmission X-ray microscope which has a resolution down to 30 nm, which is greater than a light microscope (similar to 200 nm): but retains the simplicity of sample preparation for light microscopy. The advantage of the method is that there is no requirement for extensive sample preparation. Unlike electron microscopy preparation techniques, in X-ray microscopy there is no need for dehydration, fixation, staining or coating, and the sample is imaged at ambient pressure. Viscin threads from 9 plant species were investigated, 7 from the family Onagraceae, and two Ericaceae. II was found that in some species, structural detail complemented previously presented scanning electron microscopy images of specimens. However, in a number of species we found contrasting structures, to previous scanning electron microscopy work. It was concluded that by using X-ray microscopy we were able to both complement existing knowledge, and give new information, that had previously been lost during conventional sample preparation.