Abstract :
The ultrastructure of intercellular hyphae and D-hatistoria
of P. recondita f.sp. tritici, and the host response
to haustorial invasion, was investigated. The intercellular
hyphae share common characteristics with those of other
uredial stage rust fungi. Anastomosis was observed
between intercellular hyphae. Two nucleoli were frequently
observed in a single nucleus in the haustorium,
indicating possible nuclear fusion between the two nuclei
in D-haustoria of this fungus. The close association of
host organelles, such as the nucleus, Golgi bodies, endoplasmic
reticulum, vesicles and mitochondria, with the
developing haustorium, is described
