Phenotypic screening of IRRI’s rice accessions for resistance to blast disease in Vietnam

Abstract

Utilization of host-resistance is assumed as an effective option in rice blast management. However, blast resistance tends to be unreliable because it often fails or breaks down under field stress due to rapid adaptation of diverse toxicity and high mutation-rate of blast fungus. Therefore, large scale screening of rice germplasm originating from different regions for disease reaction has been maintained ceaselessly in order to identify suitable blast-resistance materials for rice breeding. In the present study, 40 potential rice accessions which showed blast resistance in Philippines were evaluated for disease reaction against 12 M. oryzae isolates specific for different regions in Vietnam. Although all of studied accessions were susceptible with Southern blast fungi, 20 accessions were shown highly resistant reaction against 10/10 isolated blast fungi originated from Northern part of Vietnam.