Esperance Munganyinka, Richard Edema, Jimmy Lamo and Paul Gibson
A study was conducted in a green house of National Crop Resource Research Institute, Uganda to determine the reaction for resistance to rice yellow mottle virus (RYMV) in nine rice genotypes. Four were interspecific (N-1, N-4, N-6 and Naric 1) and five intraspecific (two locals K5 and K85, and three introduced WAC 116, WAC117 and Gigante). The screening of these parental materials for resistance to RYMV was done by artificial inoculation with a virulent isolate from Iganga. For among the materials tested, none was found to be immune. The results revealed four patterns of reaction to RYMV among the cultivars: three resistant (WAC 116, WAC 117 and Naric1), four moderately resistant (Nerica 6, Nerica 4, Nerica 1 and Gigante) and two susceptible (K85 and K5). In the current study, Gigante was recorded to have the severity of RYMV symptoms. Furthermore, lines WAC 116, WAC 117 and Naric1 were identified as sources of resistance to RYMV, and therefore candidates for use as parents to improve resistance in susceptible preferred local rice varieties.