NoteMolecular Structure of rDNA RepeatUnitin Magnaporthe grisea JSeeA

Magnaporthe grisea is an ascomycete that is the causal agent of rice blast disease. The disease is one of the most destructive diseases of rice for the significant loss of the crop. The major strategies for defense against the disease are drugs and resistant cultivars, However, the fungus has been known to be highly variable with respects to drug resistance and host cultivar specificity, and those features have made it hard to control the disease permanently.i} In order to establish a novel disease defense system, it is necessary to clarify the process of the mutations that introduce the variability. Until now, molecular cloning of genes for the host or cultivar specificity,2'4) the construction of genetic maps,5) DNA fingerprinting using repetitive DNA probes,`・') identifications f transposable elements,S"3] and electrophoretic karyotyping6'i4'iS) have thrown a light on