A Toolbox for Managing Blast and Sheath Blight Diseases of Rice in the United States of America

Abstract

Rice blast disease caused by the fungus Magnaporthe oryzae and rice sheath blight disease caused by the fungus Rhizoctonia solani are two major hurdles for stable rice production worldwide. Presently, fungicides are still needed to manage these two devastating fungal pathogens. After two decades of research efforts, a toolbox has been assembled with the following components: (1) insight into pathogen genomic identity and pathogen avirulence (AVR) genes that can be used to enhance plant breeding; (2) new mapping populations and germplasm and genetic stocks that can be used as starting materials to identify effective host resistance (R) genes; (3) user-friendly disease evaluation methods that can be used to accelerate the identification and utilization of R genes; (4) validated effective R genes that are readily available for improving genetic resistance; (5) host genetic markers that can be used to accelerate the development of new resistant germplasms/cultivars; and (6) an improved understanding of resistance mechanisms that can facilitate the engineering of resistance in commercial varieties. Appropriate employment of these tools in breeding and crop protection will reduce production costs and create an environmentally benign, sustainable rice production system.