Citrus yellow mosaic badnavirus infecting Citrus sp.: a threat to the citrus industry and a quarantine issue

Among the virus diseases affecting the citrus industry in southern parts of India, the most devastation is caused by citrus tristeza virus (CTV) followed by citrus yellow mosaic badnavirus (CMBV). Research analysis reveals that the longevity of the trees, quality of fruit appearance, juice and ascorbic acid content are lowered in CMBV-infected citrus. CMBV is chiefly propagated through infected budwood, which is used in graft propagation of citrus species. Symptoms of the mosaic disease caused by the virus are always confused with those of mineral deficiencies and is the main reason for CMBV spread through graft propagation in nurseries. CMBV could also co-exist as a mixed infection with CTV. This mixed infection of CMBV and CTV causes even more devastation than CTV infection does alone. At present, this virus is limited to the southern parts of India. If CMBV is not properly diagnosed at the quarantine level, there is a high risk of virus movement to other citrus-growing countries of the world, especially for the border countries of India.