Wild species of Oryza are an important source of tolerance for biotic and abiotic stresses. Several genes of agronomic importance such as those that confer resistance to blast, bacterial leaf blight, brown planthopper, tungro, and grassy stunt virus have been transferred from wild species into elite breeding lines of rice, including the quantitative trait loci (QTLs) for biotic and abiotic stress resistance that have been identified earlier (Brar and Khush 1997, Amante-Bordeos et al 1992).
Blast, caused by the fungus Pyricularia grisea, is one of the most destructive diseases of rice. Surveys done by Widawsky and O'Toole (1990) and Geddes and Iles (1991) confirm that it remains a serious constraint to rice production in South Asia. Host-plant resistance is the most promising method to control blast (Bonman et al 1992). We report here the transfer of broad-spectrum resistance to blast and salinity tolerance from O. rufipogon into high-yielding variety B90-15 (IET15420).