Akinori Ueyama

Pseudocochliobolus nisikadoi, the perfect state of Helminthosporium coicis

The perfect state of Helminthosporium coicis, causing leaf-blight disease of Coix species, was produced on Sachs agar medium with rice straw by the same method described in previous papers on perfect state formation of H. oryzae and Cochliobolus miyabeanus. Morphologically, the perfect state is somewhat different from Cochliobolus, especially in the existence of basal columnar stromata and of ascospore arrangement with parallel to loose coiling in the ascus. Thus a new genus, Pseudocochliobolus, is described. Pseudocochliobolus nisikadoi is designated as type species of the new genus.

Pseudocochliobolus Australiensis, the Ascigerous State of Bipolaris Australiensis

Two species formerly included in the genus Drechslera, D. hawaiiensis and D. australiensis, are transferred to Bipolaris. Both species have bipolar conidium germination and produced the ascigerous state in Sachs agar medium with rice straw. They are disposed in Pseudocochliobolus on the basis of their morphology. Pseudocochliobolus australiensis is described as a new species for the ascigerous state of B. australiensis. Both species are heterothallic and the two mating types are governed by the same single-gene alleles.

PSEUDOCOCHLIOBOLUS VERRUCULOSUS AND VARIABILITY OF CONIDIUM MORPHOLOGY

The teleomorph of Curvularia verruculosa, the new species Pseudocochliobolus verruculosus, was produced in culture by crossing compatible isolates. The species is heterothallic, and two mating types were detected in conidium isolates both from Burma and Japan. Conidium morphology is variable among isolates, and varies within an isolate on different media.

Formation of abnormal mycelium ofFusarium roseum link. on a modified Czapek-d-amino acid medium

Es wird über den Einfluss von einigend-Aminosäuren auf den morphologischen Charakter vonFusarium roseum Link. berichtet. Von den geprüften Aminosäuren spieltd-Arginin eine wichtige Rolle für die Bildung der hefeähnlichen Zellen.l- und besondersd-Valin beschleunigen die Bildung von Chlamydosporen-ähnlichen Zellen.

Ascocarp production of Magnaporthe salvinii in culture

Nutritional and physical factors affecting ascocarp production of the causal agent of rice stem rot, Magnaporthe salvinii , were studied in a cross between Japanese isolates. Mature ascocarps were produced on several agar media with rice culms. The optimum temperatures for mature ascocarp production were from 22 to 26 °C. Light and dark greatly influenced ascocarp production, since no mature ascocarps were produced in continuous darkness.