Reported in several countries. Impacts on yield are unknown.

The virus was first detected in sweetpotato originating from Puerto Rico. It has been found in a complex with sweetpotato feathery mottle virus (SPFMV)  from the South Pacific Region (including Tonga, Papua New Guinea, New Zealand, Solomon Islands, Australia and New Zealand), Madeira, Kenya, Uganda, and U.S.A.

Sweetpotato plants infected with SPCaLV usually show no obvious viral symptoms. Sometimes infected plants may show interveinal chlorosis or faint chlorotic spots which may develop into general chlorosis, wilting and premature death of leaves.

This virus has isometric particles 50 nm in diameter that contain a major polypeptide of Mr 42-44 KD and dsDNA. SPCaLV is not serologically related to other caulimoviruses: cauliflower mosaic, dahlia mosaic, carnation etched ring and soybean chlorotic mottle.

Virus particles and characteristic intracellular inclusions induced by the virus are readily detected in the cytoplasm of epidermal and vascular parenchyma cells of infected plants. Ultra structural studies have shown that infected vascular parenchyma cells containing inclusions sometimes protrude into, and so cause occlusion of adjacent xylem vessels, which results in wilting and premature abscission of infected leaves.

SPCaLV is not mechanically transmitted or by seed or by contact between plants. Its vector is unknown. The virus does not appear to be transmitted by aphids M. persicae and Aphis gossypii.

Host range

The only known natural host of SPCaLV is Ipomoea batatas. In the laboratory, SPCaLV  can be made to infect Ipomoea setosa and Nicotiana megalosiphon.

International exchange of virus-free germplasm.

Use of healthy planting materials.

Atkey, P.T. and Brunt,  A.A. 1987. Electron microscopy of an isometric caulimo-like virus from sweet potato (Ipomoea batatas). J. Phytopathol. 118: 370-376.

Brunt A.A., Crabtree K., Dallwitz, M.J., Gibbs, A.J., and Watson, L. (eds.). 1996. Viruses of Plants: Descriptions and lists from the VIDE database. CAB INTERNATIONAL, Cambridge, UK. 1484 p.

Brunt, A.A., Crabtree, K., Dallwitz, M.J., Gibbs, A.J., Watson, L. and Zurcher, E.J. (eds.) (1996 onwards). `Plant Viruses Online: Descriptions and Lists from the VIDE Database. Version: 20^th August 1996.' URL http://biology.anu.edu.au/Groups/MES/vide/

Clark, C.A., and Moyer, J.M. 1988. Compendium of sweetpotato diseases. The American Phytopahological Society. APS Press, Minnesota, USA. 74 p.

Contributed by: Segundo Fuentes  and Luis Salazar

Taxonomy

Economic importance

Geographical distribution

Symptoms

Morphology

Biology and ecology

Host range

Management

References

Pale spots between leaf veins due to SPCaLV (S. Fuentes & L. Salazar).

Discolouration between veins (chlorosis) that may also be described as faint mottling (S. Fuentes & L. Salazar).

Chlorotic flecks along the secondary veins and interveinal chlorotic spots on leaf of a SPCaLV graft-inoculated Ipomoea setosa plant. (Right) Leaf from a healthy plant (S. Fuentes & L. Salazar).