Leaf scald caused by Monographella albescens is one of the major rice (Oryza sativa) diseases in Brazil. Somaclones derived from immature panicles of IAC 47 were assessed for genetic resistance to leaf scald under natural field conditions of infection and artificial inoculation tests in the greenhouse. The differences among somaclones in relation to incidence and severity were significant in the field. The disease severities ranged from 12.4% to 32.03% for somaclones SCIA14 and SCIA28, respectively. The relation between incidence and severity was linear and positive (r = 0.87; P <= 0.01). The lesion length on the leaves of somaclones inoculated with mycelial discs positively correlated with severity (r = 0.93; P <= 0.01) and incidence in the field (r = 0.88; P <= 0.01). The relation between flag leaf width and leaf scald susceptibility of somaclones was linear and positive. Considering disease assessment, both in field and greenhouse, 19 somaclones showed higher degree of resistance compared to the cultivar IAC 47.
