Ultrastructure of septal pore apparatus in the lamellae of Nematoloma puiggarii

Abstract

The lamellae of Nematoloma puiggarii have dolipore–parenthesome septa like the majority of the basidiomycetes. The septal pore canal is almost always transected by a central electron-dense zone. Often two more electron-dense zones, one on each side of the central one, are present in the canal. Pore canal openings are normally occluded by granular electron-dense plugs which are ring like in subbasidial and subhymenial septa and appear solid in some tramal septa. A hemispherical fibrous outer cap is always present outside the parenthesomes of subhymenial septa. Tramal septa do not have outer caps, and the subbasidial septa have them only on the subhymenial sides. The outer caps are usually delimited externally by either the cisternae of endoplasmic reticulum or by the tonoplast of adjacent vacuoles.