Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 20, 2013
Publication Date: July 1, 2013
Citation: Jia, Y. 2013. Global efforts in managing rice blast disease. American Phytopathological Society Abstracts. 112-S. Technical Abstract: Rice blast disease caused by the fungus Magnaporthe oryzae is a major destructive disease threatening global food security. Resistance (R) genes to M. oryzae are effective in preventing infections by strains of M. oryzae carry the corresponding avirulence (AVR) genes. Effectiveness of genetic resistance is often limited by humidity and temperature during the rice growing season. Consequently, blast disease is managed with an array of tools including the use of R genes, fungicides and sophisticated cultural practices. Since the first identification of R genes decades ago, over 100 blast R genes have been mapped in clusters on rice chromosomes. Among them, 20 major and 2 minor blast R genes have been molecularly characterized, and the molecular basis of resistance and molecular markers for some critical R genes has been developed for rice breeding. However, AVR genes in M. oryzae have been known to be highly unstable and changes due to transposition, point mutations, and deletions of AVR genes have been observed in field and laboratory isolates worldwide. Consequently, resistance based on one or few R genes can be quickly broken down. Additionally, fungicide resistance, and alteration of humidity, air and water temperature due to global warming present additional serious challenges for rice blast management. Ideas for global collaboration on battling blast will be presented.