Summary
Ultrastructural investigations of dormant and germinated sporangiospores ofRhizopus arrhizus were conducted by the use of thin sectioning and freeze-etching procedures. Dormant spores contained deep furrows and prominent ridges with swellings along the sides of the ridges. The furrows and ridges almost disappeared as spores swelled during germination. The plasma membranes contained protuberances or depressions (approximately 50 nm diam) depending upon the nature of the fracture. Mitochondria in dormant spores were spherical and contained few cristae compared to mitochondria of germinated spores which were larger, more diverse in shape and contained abundant cristae. Treatments of spores with 20–25% glycerol prior to freeze-etching or thin sectioning resulted in the production of artifacts between the cell wall and the plasma membrane. Vesicles were rarely observed at the apices of young germ tubes, but were present in abundance in growing hyphal tips. Surface views of young germ tubes revealed the presence of microfibrils.
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Hess, W.M., Weber, D.J. Ultrastructure of dormant and germinated sporangiospores ofRhizopus arrhizus . Protoplasma 77, 15–33 (1973). https://doi.org/10.1007/BF01287290
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DOI: https://doi.org/10.1007/BF01287290