Chiang Mai Journal of Science

 The objectives of this study were to evaluate the genetic diversity and the pathogenicity of some Vietnamese rice blast fungus (Magnaporthe oryzae Barr) populations collected from four specific different areas in Central Vietnam by using molecular analysis. The results showed that the virulence range-isolate of the blast population is highly varied. By using the polymorphic RAPD markers for genetic diversity evaluation of 32 M. oryzae isolates, it found 222 out of 303 bands were polymorphic with size ranging from 100 to 1500 bp. The isolates were further classified into seven major groups (Mo-1 to Mo-7) at a mean level of similarity of approximately 67% and the effectiveness of some resistance genes (Pik, Pik-p, Pik-h, Piz, Pi4(t), Pish, Pi1, Pi7(t), Pi9(t), Pik-m and Pita) which might be pyramided to provide durable resistance to blast fungus in Central Vietnam. This is the first report on the genetic diversity of M. oryzae isolates from the hotspots of rice blast in Central coast areas of this country.