Identification of sources of resistance to irrigated rice brown spot disease

Abstract

Fifty rice genotypes were evaluated for sources of resistance to brown spot disease (Helminthosporium oryzae Brada de Haan), under greenhouse conditions in raised beds similar to Ou's blast nursery. Inoculations were made separately with H-1 isolate and with a mixture of H-1, H-5 and H-8 isolates previously cultivated in a potato-dextrose agar (PDA) medium + Streptomycin (100 μg/1) on 30 days old seedlings. The results showed differences among some of the genotypes in relation to the degree of resistance to H. oryzae.