Surface structure of the urediniospores of Puccinia coronata f. sp. avenae

Abstract

The surface structure of the echinulate urediniospores of Puccinia coronata f. sp. avenae race 320 was examined with the light microscope and the electron microscope. The scanning electron microscope revealed a network of ridges encircling the spines. On many urediniospores, small ring-like ridges, about 1 μ across, closely encircled the bases of the spines and sometimes were connected by fine linear ridges. On other spores, the ridges took the shape of four- to seven-sided polygons, 2–3 μ across, with triangles at their corners.