DNA Fingerprinting and Sexual Characterization Revealed Two Distinct Populations of Magnaporthe grisea in Wheat Blast from Brazil

The wheat blast caused by Magnaporthe grisea (Hebert) Barr (anam. Pyricularia grisea Sacc.) is a disease reported only in Brazil and other countries of the Southern Cone of Latin America. The yield loss, lack of resist- ant varieties, absence of efficient fungicides to protect wheat spikes, and its geographical distribution have made the disease a major problem in wheat producing states of the country. The origin of the wheat blast generated much speculation until it was demonstrated that the causal agent was different from the rice blast pathogen. The present work showed that two distinct populations of M. grisea are causing wheat blast disease in Brazil based on the existence of isolates with different sexual characteristics and distinguished DNA fingerprinting. Sexual reproduction is suggested for one subpopulation of the wheat blast disease.