Yoshikatsu Fujita

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Magnaporthe oryzae is the causal agent of rice blast disease, a devastating problem worldwide. This fungus has caused breakdown of resistance conferred by newly developed commercial cultivars. To address how the rice blast fungus adapts itself to new resistance genes so quickly, we examined chromosomal locations of AVR-Pita, a subtelomeric gene family(More)
A small and extra chromosome of 1.6 Mb was previously identified in a Pyricularia oryzae strain, 84R-62B. To understand a role of the 1.6 Mb chromosome in the pathogenic changeability of P. oryzae, we performed experiments designed to characterize the 1.6 Mb chromosome in the present study. A gene family encoding secreted protein Pex31s in P. oryzae(More)
In order to clone and analyse the avirulence gene AVR-Pia from Japanese field isolates of Magnaporthe oryzae, a mutant of the M. oryzae strain Ina168 was isolated. This mutant, which was named Ina168m95-1, gained virulence towards the rice cultivar Aichi-asahi, which contains the resistance gene Pia. A DNA fragment (named PM01) that was deleted in the(More)
The pathogenicity of progeny from crosses among three Chinese isolates of Magnaporthe grisea collected from rice was tested on three Japanese differentials (Ishikarishiroke, Aichiasahi, K 59) having the blast resistance genes Pii, Pia, and Pit, respectively. Monogenic control was demonstrated for avirulence to the differentials. To identify resistance genes(More)
Twenty-eight Pyricularia isolates from two wild foxtails—green foxtail (Setaria viridis) and giant foxtail (S. faberii)—in Japan were taxonomically characterized by DNA analyses, mating tests, and pathogenicity assays. Although most of the isolates failed to produce perithecia in mating tests with Magnaporthe oryzae, a diagnostic polymerase chain(More)
A Japanese differential rice cultivar K60 was tested with 114 F1 cultures of Magnaporthe oryzae from a cross between isolates 84R-62B and Y93-245c-2. Segregation patterns of avirulence and virulence in the progeny suggested that avirulence on cv. K60 was controlled by a single gene derived from 84R-62B and tentatively named AvrK60. In the F1 population,(More)
The hypersensitive response (HR) of plants is one of the earliest responses to prevent pathogen invasion. A brown dot lesion on a leaf is visual evidence of the HR against the blast fungus Magnaporthe oryzae in rice, but tracking the browning process has been difficult. In this study, we induced the HR in rice cultivars harboring the blast resistance gene(More)
The rice cultivar ‘Chumroo’ is commonly cultivated in the mid- and high-altitude areas of Bhutan. This cultivar has shown durable blast resistance in that area, without evidence of breakdown, for over 20 years. Chumroo was inoculated with 22 blast isolates selected from the race differential standard set of Japan. The cultivar showed resistance to all the(More)