Diplodiella oryzae Miyake - Diplodiosis of Rice

Systematic position.

Division Deuteromycota, class Coelomycetes, order Sphaeropsidales, family Sphaeropsidaceae.

Biological group.


Morphology and biology.

The fungus develops on leaves and scales. In autumn the fungus develops on leaves as a parasite, in summer it can be isolated from roots. Pycnidia are almost surface, spherical or flattened-spherical, with papillary apex, with aperture, black-brown, thick-walled, 120-200 mkm in diameter, 120-180 mkm in height. Conidia are ellipsoidal or oblong-oval, brown, with one transverse septa, 9-13x2.5-3 mkm.


In the former USSR the Diplodiosis of Rice was found in the Russian Far East only, in areas being close to Japan, where this fungus hurts rice fields.


The fungus develops at high air humidity and at temperature 14 to 29.C. The optimum for the fungus temperature range is 22-26.C.

Economic significance.

The disease causes yellowing of leaves, decreased germination of seeds. Protection measures are use of plant cultivars being less susceptible to the disease; agronomical measures, application of fungicides.

Related references:

Egorova L.N., Ostenyuk G.I. 1983. Specific structure of fungi in soil of rice fields in Primorskii Territory. Mikologiya i fitopatoligiya 17(2): 97-102 (in Russian).
Egorova L.N., Ostenyuk G.I., Blokhina M.V. 1986. Micoflora of rice seeds in Primorskii Territory. In: Vasil.eva L.N. Azbukina Z.M., eds. Flora and taxonomy for spore plants of the Far East. Vladivostok: AN USSR, DVNTs BPI, p. 106-125 (in Russian).
James P.W., Hawksworth D.L. 1971. Ainsworth & Bisby.s dictionary of the fungi. 6th edition. Kew: CAB, 663 p.
Pidoplichko N.M. 1978. The fungi . parasites of cultivated plants. Keys. Kiev: Naukova Dumka, 3, 230 p. (in Russian).

© Bilder I.V.

Photo Bilder I.V.

Web design —
Kelnik studios