Understanding the evolution of molecular interactions between pathogens and their hosts is crucial for sustainable crop disease control. Pyricularia oryzae is a multihost fungal pathogen causing blast disease in rice and other grasses. This fungus is a rapidly evolving pathogen, globally threatening food security through changes in host range and adaptation to new resistant cultivars. First, to identify virulence genes involved in adaptation of P. oryzae to new rice varieties, we performed genome-wide association studies of a rice-infecting population from Yunnan (China), where the pathogen has been characterized to reproduce sexually. Genome-wide association between genotypes and virulence phenotype on 16 rice varieties and isogenic lines which differed from each other by introgression of different major resistance genes, identified new candidate genes involved in the adaptation of P. oryzae to major resistance traits introgressed in rice varieties. Then, to identify molecular processes underlying the evolution of fungal virulence and adaptation to new host genus, we gathered available raw whole genome sequencing data (Illumina, Nanopore, PacBio) from our lab and public databases to perform genome assemblies and gene predictions in a standardized manner. The genomes of 567 isolates on 24 host plant genus from 50 countries will be used to characterize effector gene repertoires and secondary metabolites to gain insight into the genetic bases of the adaptation of this pathogen to new hosts.