2.2. Designing and screening virus-specific primers
To develop an efficient multiplex RT-PCR system, gene sequences
from the four viruses and a rice actin gene sequence were
retrieved from the GenBank database of the National Center for
Biotechnology Information. The coat protein genes of RBSDV,
SRBSDV, RGDV, and RRSV were the most conserved genes (Deng
et al., 2007; Pattayawat et al., 2004; Wang et al., 2010), and