Rice tungro is one of the most devastating rice diseases in South and Southeast Asia. It is caused by two viruses, rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV). RTBV is responsible for symptom development. Its transmission by leafhopper depends on RTSV which, by itself, does not cause marked symptoms.
Two strains of RTBV have been reported previously, one from the Indian subcontinent, the other from Southeast Asia. The nearest that two RTBV strains were found is Assam in India, Dhaka in Bangladesh (Indian strain), and central Thailand, a distance of about 1500 km. These two regions are not separated by a rice-free area; Myanmar produces considerable rice. Although tungro has been suspected to occur in Myanmar, it has not been identified there. We were interested in seeing which RTBV strain can be found in Myanmar.