Rice virus disease in Indonesia: epidemiology and varietal resistance

The geographical location of Indonesia in the tropical region, characterized by high temperatures and humidity, is favorable for the development of viral diseases in rice. Climate change and intensive rice production systems further exacerbate the detrimental effects of viral diseases on rice sustainability. Three major rice virus diseases in Indonesia—rice tungro disease (RTD), rice rugged stunt virus (RRSV), and rice grassy stunt virus (RGSV)—have affected more than 170,000 ha of rice from 2010 to 2022. Key factors contributing to viral disease epidemics in the country include the extensive planting of high-yielding varieties twice a year, intensive use of fertilizers, asynchronized planting, and erratic climatic conditions. Cultivating rice varieties that are resistant to both viruses and their vector insects is the most effective and efficient strategy for the integrated pest management of rice viral diseases. The development of RTD-resistant rice varieties has been relatively successful in Indonesia, as demonstrated by the release and adoption of 18 resistant varieties. However, the development of RRSV and RGSV-resistant varieties remains challenging due to a lack of genetic resources for improving rice resistance. Progress has been achieved only by developing varieties resistant to brown planthoppers as vectors of these virus diseases. To address these challenges, the potential use of genetic technology to develop rice that is resistant to viral diseases is discussed.