VIEW ARTICLE

Genetics

Evidence of a Gene-for-Gene Relationship in the Oryza sativa-Magnaporthe grisea Pathosystem. Drissa Silué,, Laboratoire de phytopathologie, Institut de Recherches Agronomiques Tropicales et des Cultures Vivrières, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), BP 5035, 34032 Montpellier Cedex 1, France; Jean Loup Notteghem, and Didier Tharreau. Laboratoire de phytopathologie, Institut de Recherches Agronomiques Tropicales et des Cultures Vivrières, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), BP 5035, 34032 Montpellier Cedex 1, France. Phytopathology 82:577-580. Accepted for publication 18 November 1991. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/Phyto-82-577.

A cross was made between two field isolates of Magnaporthe grisea pathogenic to rice. Full-sib crosses between F₁ ascospores, followed by backcrosses to the female fertile parent GUY11, produced perithecia fertile enough for tetrad isolation. Genetic analysis of the pathogen revealed that avirulence to the rice cultivar Pi-n°4 is controlled by one gene (Avr1-Pi-n°4) unlinked to the gene MAT1-1, which is responsible for mating type. Additionally, resistance of Pi-n°4 was found to be controlled by one gene. Thus, existence of a gene-for-gene relationship was shown for the pathosystem Oryza sativa-M. grisea.