2.3 Comparison of the ultrastructure of dormant and non-dormant
chlamydospore
Under scanning electron microscope, the dormant spores did not germinate
after 12 h of culture (Figure 3A), but the shape of spores were round
and full. The non-dormant spores had germinated (Figure 3B), the
germination tubes were extended, and the surface was locally deflated.
There were nodules on the surface of both types of spores but no obvious
differences. The transmission electron microscope (TEM) image shows the
internal structure of the spore. The spore wall is composed of outer
shell, outer membrane and cortex from the outside in (Figure 3C, 3D, 3E
& 3F). The white transparent part of the spore wall, with certain
electron transmittance, is the inner wall of the spore, or the cortex.
Due to the high electron permeability, the inner wall of the dormant
spore forms a thick white zona pellucida, which is significantly thicker
than that of the inner wall of the non-dormant spore, and several times
the difference can be observed. The cytoplasm of non-resting spores is
full of many round, regular and small liposome contents, and there are
also a few glycogen particles with low electron density. As the resting
spores aging process, many cytoplasmic vesicles gradually fuse to form
several large nearly spherical masses (possibly liposome spheres). The
nuclei are crowded to the near edge, and the nuclei are lobulated. There
are still some glycogen-like particles with low electron density in the
edge of the cytoplasm.