Mycoscience (2001) 42, 389-394

Shuhei Tanaka, Shin-Ichi Ito and Mitsuro Kameya-Iwaki (2001)
Electron microscopy of primary zoosporogenesis in Plasmodiophora brassicae
Mycoscience 42 (4), 389-394
Abstract: Primary zoosporogenesis in resting sporangia of Plasmodiophora brassicae that had been incubated for 14 d in culture solution containing turnip seedlings was examined by transmission electron microscopy. A single zoospore differentiated within each sporangium, the differentiation being initiated by the emergence, of two flagella in the tight space formed by invagination of the plasma membrane within the sporangium. The differentiazing zoospore was similar in intracellular aspects to sporangia within clubroot galls. Then a deep groove formed on the zoospore cell body by further invagination of the plasma membrane. Two flagella appeared to coil around the zoospore cell body in parallel along this groove. Thereafter, the cell body lost the groove and became rounded following the protoplasmic condensation (contraction of cell body) during late development, and assumed an irregular shape at the stage of maturation. Intracellular features in, developing and mature zoospores were complicated, being characterized by electron-dense nuclei and mitochondria, microbodies, cored vesicles and various unidentified cytoplasmic vesicles and granules. A nucleolus-like region was observed only in the nucleus of the mature zoospore. A partially opened germ, pore was also seem in the sporangium containing the mature zoospore.
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Link to article at publishers website
Database assignments for author(s): Shin-ichi Ito

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plasmodiophora brassicae