ARS | Publication request: THE POPULATION BIOLOGY OF THE RICE BLAST PATHOGEN MAGNAPORTHE GRISEA IN THEUNITED STATES

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: September 12, 2002
Publication Date: N/A

Technical Abstract: Genetic and molecular markers have been used to characterize population diversity of the M. grisea, and include DNA fingerprinting with the repetitive element MGR586, mating type genes, avirluence genes, and vegetative compatibility. Eight DNA fingerprint lineages of M. grisea have been identified in the U.S., but only four appear to be common in the contemporary population. Tests for vegetative compatibility have been useful for genetically characterizing isolates and the data indicate that certain statistically robust MGR586 lineages are nested within certain vegetative compatibility groups. The various markers support the hypothesis that M. grisea is reproducing asexually and novel virulences originate through mutation of avirulence genes within the endemic population. Isolates of M. grisea can readily be recovered from non-rice hosts near rice fields, but the vast majority of these isolates are unable io infect rice and appear to be genetically distinct from the rice blast pathogen.