CMV and ToMV (mosaic viruses)

Context

Farmers in Maharashtra have said their tomato crop was impacted by attacks of the cucumber mosaic virus (CMV), while growers in Karnataka blamed the tomato mosaic virus (ToMV). What are CMV and ToMV?

• The two plant pathogens have similar names and cause similar damage to crops, but they belong to different viral families, and spread differently.

Tomato mosaic virus (ToMV)	Cucumber mosaic virus (CMV)
It belongs to the Virgaviridae family and is closely related to the tobacco mosaic virus (TMV). Host: ToMV hosts include tomato, tobacco, peppers, and certain ornamental plants. Spread: Through infected seeds, saplings, agricultural tools and often, through the hands of nursery workers.	It belongs to the genus Cucumovirus (family Bromoviridae). Host: Cucumber, melon, eggplant, tomato, carrot, lettuce, celery, cucurbits (members of the gourd family, including squash, pumpkin, zucchini, some gourds, etc.), and some ornamentals. CMV was identified in cucumber in 1934, which gave the virus its name. Spread: by aphids (sap-sucking insects), human touch (extremely low chances).
Impact: Both viruses can cause almost 100 per cent crop loss unless properly treated on time.

 Significant plant virus diseases in India

• Begomoviruses
• Badnaviruses
• Cucomoviruses
• Potyviruses
• Ilarviruses