Novel Sources of Wheat Head Blast Resistance in Modern Breeding Lines and Wheat Wild Relatives

Wheat head blast (WHB), caused by the fungus Magnaporthe oryzae pathotype triticum, is a devastating disease affecting South America and South Asia. Despite 30 years of intensive effort, the 2N V S translocation from Aegilops ventricosa contains the only useful source of resistance to WHB effective against M. oryzae triticum isolates. The objective of this study was to identify non-2N V S sources of resistance to WHB among elite cultivars, breeding lines, landraces, and wild-relative accessions. Over 780 accessions were evaluated under field and greenhouse conditions in Bolivia, greenhouse conditions in Brazil, and at two biosafety level-3 laboratories in the United States. The M. oryzae triticum isolates B-71 (2012), 008 (2015), and 16MoT001 (2016) were used for controlled experiments, while…