Analysis of host species specificity of Magnaporthe grisea toward foxtail millet using a genetic cross between isolates from wheat and foxtail millet

• Published in: Phytopathology 2003, Vol.93 (1), p.42-45
• Main Authors: Murakami, J, Tomita, R, Kataoka, T, Nakayashiki, H, Tosa, Y, Mayama, S
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; cultivars; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; gene-for-gene relationship; genetic variation; Genetics and breeding of economic plants; host specificity; host-pathogen relationships; Magnaporthe grisea; pathogenicity; pathotypes; Pest resistance; Phytopathology. Animal pests. Plant and forest protection; plant pathogenic fungi; Plant pathogens; Setaria italica; Triticum aestivum; Variation, races, biotypes, parasitic specialization, genetics; Varietal selection. Specialized plant breeding, plant breeding aims
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/phyto.2003.93.1.42

ABSTRACT Host species specificity of Magnaporthe grisea toward foxtail millet was analyzed using F(1) cultures derived from a cross between a Triticum isolate (pathogenic on wheat) and a Setaria isolate (pathogenic on foxtail millet). On foxtail millet cvs. Beni-awa and Oke-awa, avirulent and virulent cultures segregated in a 1:1 ratio, suggesting that a single locus is involved in the specificity. This locus was designated as Pfm1. On cv. Ki-awa, two loci were involved and one of them was Pfm1. The other locus was designated as Pfm2. Interestingly, Pfm1 was not involved in the pathogenic specificity on cv. Kariwano-zairai. These results suggest that there is no "master gene" that determines the pathogenic specificity on all foxtail millet cultivars and that the species specificity of M. grisea toward foxtail millet is governed by cultivar-dependent genetic mechanisms that are similar to gene-for-gene interactions controlling race-cultivar specificity.