Sheath Blight Disease in Wild Rice
NIFA NRI-funded researchers of the Applied Plant Genomics Rice Coordinated Agricultural Project (CAP) discovered a breakthrough for breeding for sheath blight resistance in rice. Sheath blight is a major disease of rice in the United States and worldwide, affecting more than 50 percent of all global rice production areas. Some rice cultivars, found in various areas of the world, have been identified as moderately resistant to sheath blight; however, no fully resistant cultivars have been discovered to date.
Wild relatives of rice (Oryza species) are a source of novel sheath blight resistance genes because they often contain new pest resistance genes that can then be incorporated into cultivated rice varieties to improve pest resistance. The response of 73 Oryza genotypes originating from different areas of the world to sheath blight disease were evaluated to identify resistant sources. Seven accessions, representing the wild species Oryza barthii, Oryza meridionalis, Oryza nivara, and Oryza officinalis, were identified as moderately resistant to sheath blight.
Efforts are now underway to further identify the sheath blight resistance gene(s) and incorporate this resistance into rice varieties adapted to the United States. Rice breeders will use these U.S. adapted varieties to develop new and improved rice cultivars that are resistant to sheath blight disease.
These findings were reported in the November 2008 issue of the journal Plant Disease.
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