Scanning electron microscopic study of clamp connections in higherBasidiomycetes

Clamp connections on vegetative hyphae of six species belonging to different groups of higherBasidiomycetes were studied by scanning electron microscopy. Different types of clamps, short and long, high and low, small and large, gently or abruptly curved, medallion-type and without a slit, single, coupled and in whorls, as well as clamps occurring on anastomoses were observed. No characteristic features usable for the species-specific differentiation of the vegetative mycelia of higherBasidiomycetes were found. Greater variability in the type of clamps, especially in their distribution on hyphae, found in species belonging toAphyllophorales contributes to the theory of their relative primitivism in comparison withAgaricales.