The fine structure of septal pore apparatus in the lamellae of Pholiota terrestris

Abstract

The fine structure of septal pore apparatus in the lamellae of Pholiota terrestris WELLS, K. 1978. The fine structure of septal pore apparatus in the lamellae ofP/~oliottr terrestris.Can. J. Bot. 56: 2915-2924. L'auteur a observe les lamelles du Plloliottr tprre.stri.s en coupes minces passant par un plan perpendiculaire B la surface hymtniale. Les lamelles consistent en une couche hymeniale comportant des basides et des cystides Cparses, un subhymenium entrelace et une tr.;ime. La trame interieure comporte une zone d'articles myceliens relativement robustes et vacuoles, alors que la twme externe est constituee d'articles myceliens plus petits avec un contenu cytoplasmique relativement dense. L'appareil septal, y compris le pore, est semblabled:ins toutes les lamelles h celui decrit chez 121 plupart des autres Homobasidiomycetes et des Htterobasidiomycetes saprophytes. Au centre du pore septiil il y a une mince zone dense aux electrons qui entrecoupe le canal du pore. Dans les pores de certaines septiitions on retrouve de telles zones denses aux electrons pres de I'un 011 des deux orifices. Lacapsule du septum est constituee d'un ensemble de trois membranes; les deux membranes Iimitantes apparaissent nettement tripartites en coupe tl.ansversaIe. Les pores dans la capsule des septums sont distribues en hexagone et mesurent de 70 B 105 nm de diamtttre. Lescapsules sept;iles proximales des septumsdes sous-basides et celles du subhymenium developpent une capsule externe granulaire qui est hnbituellement delimitee exterieurement par du reticulum endoplasmique ou, moins souvent, par le tonoplaste d'une vacuole adjacente. Les pores septaux des septations des sous-basides deviennent obtures par les gonflements septaux dilates B la suite de I'expulsion des basidiospores. Dans la trame, le septum et son pore ne sont pas associks B une capsule externe; cependant plusieurs pores sept;iux de Ia trame deviennent obtures par des bouchons de materiel dense aux electrons prks des deux orifices. L'auteur compare les observations effectuees dans les lamelles du P. terrestris B celles effectuees sur d'autres Homobasidiomyctttes et HCterobasidiomycetes saprophytiques. [ T~i d u i t par lejournal] KENNETH WELLS Deprrrtt,~ent ofBotor~y, Unit'ersity of C~rlifbrnia. Dovis, CA, U.S.A. 95616 Received May 25. 1978 WELLS. K. 1978. The fine structure of septal pore apparatus in the lamellae of Pholiotcr terre~tris.Can. J. Bot. 56: 2915-2924. The lamellae of Plrolioto terrestris, when viewed in thin sections cut perpendicular to the hymenial surface, consist of a hymenial layer of basidia and scattered cystidia, an interwoven subhymenium. and a trama. The inner trama is composed of a zone of relatively large, vacuolated hyphal elements. whereas the outer trama consists of smaller hyphal elements with relatively dense cytoplasmic contents. The septal pore apparatus throughout the lamellae are similar to those described in most other Homobasidiomycetes and saprobic Heterobasidiomycetes. In the center of the septal pore there is a narrow electron...

Basidiomycota: Homobasidiomycetes

“…Molecular and ultrastructural evidence suggests that the homo basidiomycetes are nested in a clade of Basidiomycota that have biglobular spindle pole bodies, complex dolipore septa, and (usually) membrane-bound parenthesomes (Wells 1978;Moore 1980;McLaughlin 1981;Taylor 1993, 1995a,b). This group has been termed the hymenomycete lineage by Swann and Taylor (1993).…”

Ultrastructure and the taxonomy of Eocronartium

“…1968. the sporophore of Eocronartium are not unique. The dolipore-parenthesome septa from different parts of the mycelium from other taxa have already been shown to differ considerably (Flegler et al 1976;Gull 1976;Craig et al 1977;Wells 1978;Khan and Kimbrough 1979;Thielke 1972). Variations in the plugging of septal pores noticed in Eocronartium have also been seen in the Uredinales (Heath and Heath 1975;Littlefield and Bracker 1971 ;Jones 1973) and are probably indicative of the dynamic nature of the septum.…”

Contributions of Electron Microscopy to Fungal Classification

“…The SPB of members of the Ascbmycotina is a plaquelike structure. The SPB of most basidiomycetes is a dumbbell-shaped structure, composed of two fibrillar, globular elements joined by an electron den's'e rriiddle piece (Wells, 1977). Some authors have suggested that there is a chemical distinction between the ascomycete and basidiomycete SPBs (McDonald and Weijer, 1966;Girbardt, 1968Girbardt, , 1971Zickler, 1973).…”

“…On the other hand, the SPB of the Uredinales is disk-like (Heath and Heath, 1,975;Wright et al, 1978), and nuclear divisions in the rusts may differ from tho'se in other basidiomycetes. Wells (1977) proposed that "the characteristics of nuclear'divisions in the Uredinales are intermediate between those of the Ascomycotina and those of the' remaining orders of the Basidiomycotina." Fuller (1976) suggested that comparative cytological studies of fungi support the existence of a coherent group, the Zygoascobasidiomycbtina.…”