International Rice Research Institute (IRRI) Los Banos, laguna, PHILIPPINES
Rice production in Asia and Africa faces ongoing threats from Xanthomonas oryzae pv. oryzae (Xoo, bacterial blight) and Magnaporthe oryzae (Mo, blast). Effective deployment of over 100 known resistance genes depends on understanding pathogen population structure, traditionally requiring labor-intensive pathotyping. We developed PathoTracer, a molecular platform for rapid, high-throughput genotyping of field samples without conventional pathotyping. For Xoo, 40 SNP markers distinguish 12 Asian populations; for Mo, eight markers identify four major lineages. From 2019-2024, over 6,000 Xoo samples from 20 countries were analyzed, revealing dominant populations in Asia (AXoo9, AXoo12) and spread of AXoo5, 7, and 12 to Africa. PathoTracer integrates genotyping and pathotyping data to predict effective resistance genes and recommend suitable varieties. The platform (http://3.0.204.70/pathotracer2/) supports faster, more targeted deployment of resistance genes to strengthen rice production against evolving pathogen threats.
