Geographic Distribution of Avirulence Genes of the Rice Blast Fungus Magnaporthe oryzae in the Philippines

A total of 131 contemporary and 33 reference isolates representing a number of multi-locus genotypes of were subjected to a PCR test to detect the presence/absence of avirulence ( ) genes. Results revealed that the more frequently occurring genes were (81.50%), (64.16%) and (47.98%), whereas the less frequently occurring genes were (19.08%) and (5.20%). It was also laid out that the presence of genes in is strongly associated with agroecosystems where the complementary resistant ( ) genes exist. No significant association, however, was noted on the functional genes and the major geographic locations. Furthermore, it was identified that the upland varieties locally known as "Milagrosa" and "Waray" contained all the genes complementary to the genes tested.