Rice tungro spherical virus (RTSV) is one of two viruses causing rice tungro disease, a highly destructive disease of rice in South and Southeast Asia. It causes stunting, reduced number of tillers (shoots), and yellow or orange-yellow discoloration of the leaves (Hibino 1996, International Rice Research Institute 2009). Mottling, striping or interveinal necrosis of the leaves have also been observed. The virus is transmitted by several insect vectors in the cicadellid genera Nephotettix and Recilia (International Rice Research Institute 2009).