5-day old

COLONIES fast growing, covering the whole area of potato dextrose agar (PDA) medium of a diameter of 10 cm within five days of growth at a temperature of 20-24oC, grey (1E1), low, tomentous.

CONIDIOPHORES (cp) short, mostly simple, rarely slightly branched, inflated neat the tip, with a small pore at the tip, from which single, terminal conidia develop.

CONIDIA (c) shiny, pale yellow (4A3) to orange yellow (4B8), when young, olive brown (4F8) to black, when mature, 1-celled, up to 15 µm diam, or ellipsoid, 11-16 x 9.5-12 µm.

SUBSTRATE AND DISTRIBUTION. Nigrospora oryzae can colonize different living and dead plant species (Blaszkowski 1994 a, b; Blaszkowski and Piech 2002; Domsch et al. 1970; Neergaard 1977).

The fungus is widespread in all parts of the world, particularly in the tropics (Blaszkowski 1994 a, b; Blaszkowski and Piech 2002; Domsch et al. 1980; Neergaard 1977).

NOTES. The teleomorph of N. oryzae is Khuskia oryzae H. Hudson (Domsch et al. 1980). The monotypic genus Khuskia belongs to the family Trichosphaeriaceae within the order Trichosphaeriales (Kirk et al. 2001).

Nigrospora oryzae is a saprotroph colonizing debris of different plant species and a weak parasite producing grain spots of rice, sorghum, and corn (Neergaard 1977). Nigrospora oryzae has been commonly found among fungi associated with seed of different cereals (Piech, Blaszkowski 1993; Blaszkowski and Piech 2002).

REFERENCES

Blaszkowski J. 1994. The occurrence of Septoria nodorum Berk. and associated mycoflora in seeds of wheat cultivated in the Szczecin voivodeship. Acta Mycol. 29, 43-52.

Blaszkowski J. 1994. The influence of fungicides on the mycoflora of leaves of Triticum aestivum L. Acta Mycol. 29, 147-157.

Blaszkowski J., Piech M. 2002. Comparison of seed-borne fungal communities of naked and husked oats and barley. Phytopath. Pol. 24, 71-74.

Domsch K. H., Gams W., Anderson T. 1980. Compendium of soil fungi. Acad. Press. London-New York-Toronto-Sydney-San Francisco.

Kirk P. M., Cannon P. F., David J. C., Stalpers J. A. 2001. Ainsworth & Bisby’s dictionary of the fungi. Ninth Edition. CAB International.

Neergaard P. 1977. Seed pathology. The Macmillan Press Ltd. London.

Piech M., Blaszkowski J. 1993. The influence of the degree of reproduction on the mycoflora of winter XTriticosecale seeds. Bull. Pol. Ac. Sci. Biol. Sci. 41, 393-399.