Transmission of citrus ring spot virus through budwood, seed and insect-vectors.
Transmission studies, carried out in Abohar, India, indicated that citrus ringspot virus (CRSV) was readily transmissible through budwood. However, seed and insect vectors (Diaphorina citri and Dialeurodes citri) failed to transmit CRSV. Out of the various citrus indicator hosts tested for biological transmission through budwood, Kinnow mandarin, Cleopatra mandarin (Citrus reshni), Etog citron (C. medica), Rough Lemon (C. jambhiri) and Sweet yellow, symptomatic rings appeared earlier (90-92 d after inoculation) and were more conspicuous in Kinnow and Cleopatra mandarin. It is suggested that for the early and reliable biological indexing and purification of CRSV, Kinnow and Cleopatra mandarins should be used as indicator hosts. For effective and efficient management of CRSV, the use of virus free budwood is recommended for the production, multiplication and distribution of virus free nursery plants.