THE DEVELOPMENT OF ECHINULATION IN UREDOSPORES OF WHEAT STEM RUST

Abstract
Electron microscopy was used to determine the sequence of events in the formation of spines on the uredospore walls of P. graminis tritici. The micrographs show that spines develop to mature size beneath the uredospore wall and then move or pass through the wall to its surface during the expansion and maturation of the spore.