Ultrastructural Observations on the Septal Pore inCronartium Flaccidum(Alb. Et Schw.) Wint. Also in Relation to the Taxonomy of the Uredinales

Abstract

SUMMARYThe fine structure of the septum and pore in the monokaryotic and dikaryotic vegetative mycelium of Cronartium flaccidum was studied. Some ultrastructural observations on the hyphal cell of this fungus were also carried out. The hyphal septa become progressively thinner towards the pore; the septal pore shows none of the swellings and of the structures resembling the parenthesome which characterize the dolipore septum of higher Basidiomycetes. The septal pore of C. flaccidum as it as been seen in other Uredinales investigated up now, is a very simple structure morphologically similar to the septal pore of Ascomycetes. Some formations which make up the septal pore apparatus that is amorphous and electron-dense material, differentiated organelle-free cytoplasm and microbodies were observed near the septum and pore in both nuclear phases of the mycelium. It is accepted a relationship between the occurrence of microbodies and the occurrence and function of the dense material at the pore region likely t...