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ARS Home » Northeast Area » Frederick, Maryland » Foreign Disease-Weed Science Research » Research » Publications at this Location » Publication #418988
Research Project: Diagnostics and Biological Approaches for Management of Emerging Oomycete Plant Pathogens

Location: Foreign Disease-Weed Science Research

Title: Fruit and ornamental plants are natural hosts of cacao mild mosaic virus (CaMMV)

Author
item Puig, Alina
item MEDINA RODRIGUEZ, VIVIANA - Vmr Consulting
item Keith, Lisa
item DUNWELL, JIM - University Of Reading
item ULLAH, IHSAN - University Of Reading

Submitted to: PhytoFrontiers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2025
Publication Date: 5/5/2025
Citation: Puig, A.S., Medina Rodriguez, V., Keith, L.M., Dunwell, J., Ullah, I. 2025. Fruit and ornamental plants are natural hosts of cacao mild mosaic virus (CaMMV). PhytoFrontiers. https://doi.org/10.1094/PHYTOFR-10-24-0108-R.
DOI: https://doi.org/10.1094/PHYTOFR-10-24-0108-R

Interpretive Summary: Cacao mild mosaic virus (CaMMV) was discovered in Trinidad in 1943, however, within the past few years, it has been detected in Puerto Rico, Brazil, Florida, and Indonesia and may be widespread worldwide. Infected plants develop symptoms such as leaf and pod mosaic, and are reported to have decreased yield. However, no information is known about what other plant species can also be infected by CaMMV. Alternative hosts can contribute to disease spread in areas where the virus is present if insect vectors move from these infected hosts to newly established farms. To determine the virus’ host range, plants growing near CaMMV-infected cacao were sampled and tested for the presence of the virus. Numerous plants tested positive including widely grown ornamental plants and fruit trees. These results will have a significant impact by preventing introduction of the disease to new areas and reducing virus transmission in areas where CaMMV is already established.

Technical Abstract: Cacao mild mosaic virus (CaMMV), a member of the Badnavirus genus (family: Caulimoviridae) is considered an emerging disease on Theobroma cacao. It is associated with branch dieback and has been reported to reduce yield. As there is no treatment for infected plants, preventing transmission is the most effective strategy. However, to understand what inoculum reservoirs exist in the environment, it is necessary to determine the host range of the virus. To do this, plants in the Malvaceae and other families growing near CaMMV-infected cacao were sampled and tested for the presence of the virus. Numerous plants tested positive including widely grown ornamental plants and fruit trees such as Hibiscus sp., Thespesia grandiflora, and Durian (Durio sp.). These alternative hosts can contribute to disease spread by serving as inoculum reservoirs in areas where the virus is present, and could initiate infections if mealybugs move from these infected hosts to newly established farms. The CaMMV strains found on alternative hosts did not differ significantly from cacao infecting strains, suggesting recent movement between cacao and other species.