ABSTRACT: Wide hybridization was used to broaden the gene pool of japonica rice. Different approaches involving direct crosses between four japonica cultivars and eight wild species in combination with anther culture, embryo rescue, and molecular markers were used to produce interspecific hybrids, advanced alien introgression lines, dihaploids, and characterization of alien introgression. Interspecific hybrids were produced between Jinmibyeo, Ilpumbyeo, and Hwaseongbyeo cultivars of rice (O. sativa, 2n=24 AA) and wild species, O. rufipogon (2n=24, AA), O. longistaminata (2n=24, AA), O. punctata (2n=24, BB), O. minuta (2n=48, BBCC), O. alta (2n=24, CCDD), including African rice species, O. glaberrima (2n=24, AA). Crosses involving species other than A genome were produced through embryo rescue and were sterile. Following backcrossing with the recurrent japonica parents, advanced progenies have been produced for transfer of alien genes into japonica rice. As results of yield trials, three elite lines were generated from this cross; they are "Suweon 487" with resistance to black streak dwarf virus, "Suweon 497" with blast and bacterial blight resistance and "Suweon 506" with blast resistance, emonstrating that wild species genes have now become important component of japonica rice breeding.