Abstract
Comparisons were made on the fine structure of hyphae of Helminthosporium oryzae Ito et Kurib. and Pyricularia oryzae Cavara by electron microscopy.
The fine structure of the cell wall, number of nuclei, mitochondrial volume and the arrangement of cristae were found to be highly differentiated in both hyphae of H. oryzae and P. oryzae.
The results obtained are as follows:
(1) Hyphae of Helminthosporium oryzae
The cell wall of hyphae was consisted of three layers (outer, middle and inner layers), as seen in conidia, and the hyphae of this fungus were recognized to be multinucleate. The cytoplasm contained well-defined mitochondria (0.76×0.51μ), endoplasmic reticula (ER), vacuoles and unidentified spherical bodies.
(2) Hyphae of Pyricularia oryzae
Two layers (outer and inner layers) were detectable in the cell wall structures of hyphae. Each cell seemed to possess a single nucleus surrounded by a double membrane with nuclear pores. The nucleus contained a comparatively dense body identified as chromatin substance. The cytoplasm also contained coiled membrane fragments, twisted-ER, variable surfaced ER, large mitochondria (1.28×0.62μ) and lipid granules (1.50μ in diameter).
