Relationship between appressorial melanin pigmentation and penetration of Pyricularia oryzae into rice plants
Han, S.S.; Sun, H.J.
Korean Journal of Plant Pathology 6(3): 352-357
Six mutants of the rice pathogen with colourless or brown colonies were selected from the usual blackish grey colonies after UV irradiation. Two of these, 4AM-2(alm) and 4BM-1(brm), formed colourless appressoria and did not produce lesions on the Korean rice differential cultivars. Application of tricyclazole at 10 p.p.m. to a wild-type isolate of P. oryzae also resulted in colourless appressoria and no lesions on the differentials. When 3 precursors of melanin formation (scytalone, DOPA and DHN) were added to a spore suspension of the mutant 4BM-1, the DOPA treatment resulted in production of normal appressoria.