Screening for Seedling Resistance to Rice Yellow Mottle Virus in Some Rice Cultivars in Sierra Leone. S. N. Fomba, Associate Plant Pathologist, West Africa Rice Development Association, Regional Mangrove Swamp Rice Research Station, P. M. B. 678, Freetown, Sierra Leone. . Plant Dis. 72:641-642. Accepted for publication 18 September 1987. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0641.

Six hundred rice accessions (Oryza sativa) were screened for resistance to rice yellow mottle virus at the seedling stage. The trial was conducted for 4 years using a finger rub inoculation technique in a rain-fed upland nursery at Rokupr, in northwestern Sierra Leone. Most of the currently recommended rice cultivars, farmers’ traditional cultivars, and introductions were susceptible to this sap-transmissible virus. Most of the resistant or tolerant accessions were rices with a long history of cultivation in Africa or were progenies derived from them. These resistant rices invariably also possessed horizontal resistance to blast (Pyricularia oryzae), the most widespread disease of rice in West Africa. This observation makes them useful sources of resistance to both rice yellow mottle virus and the rice blast for cultivar improvement.

Keyword(s): mangrove swamp.