Magnaporthe grisea, the rice blast fungus is one of the
main pathological threats to rice crop worldwide. The
genetic relatedness and the probable mechanisms of
genetic variation among the Indian isolates of rice
blast pathogen were studied. A total of 171 polymorphic
markers were scored using 33 selected random decamer
primers. The isolates exhibited an overall polymorphism
of about 64%. The similarity degree value for
the isolates ranged from 0.76 to 0.92. The high polymorphism
could be explained by natural and stressinduced
transposition and horizontal gene transfer.
Understanding the source of pathogen variation will
aid in designing improved methods for management of
the rice blast disease.