Fine Structure of Mycota 10. Thallus Formation in Puccinia podophylli Aecia

Abstract

P. podophylli, a representative rust, is not observed to produce a hyphal system with typical basidiomycete-type dolipore-parenthesome septa in the aecia. Instead, thallus formation is arthrogenous, i.e., the sides of the invaginating plasma membrane that initiates cell division are nearly parallel and centripetal growth goes to completion to form daughter protoplasts. Each face of the invagination membrane develops discrete wall material. Initially these 2 layers are closely appressed but maturation produces centripetal separation. The final product of cytokinesis is thus, in essence, arthrospores. Aeciospores differ from these thallus cells morphologically only in their thicker walls and in a higher concentration of storage vesicles and spatially in their place of appearance.