Authors
M. Rännäli and
V. Czekaj, Department of Applied Biology, PO Box 27, FIN-00014 University of Helsinki, Finland;
R. A. C. Jones, Agricultural Research Western Australia, Locked Bag No. 4, Bentley Delivery Centre, Perth, WA 6983, and West Australian State Agricultural Biotechnology Centre, Murdoch University, Perth, WA 6150;
J. D. Fletcher, New Zealand Institute for Plant & Food Research, Private Bag 4704, Christchurch;
R. I. Davis, Northern Australia Quarantine Strategy (NAQS) and Australian Quarantine and Inspection Service (AQIS), P.O. Box 1054, Mareeba, Queensland 4880;
L. Mu, Service du Dévelopement Rural, Département de la Protection des Végétaux, BP 100, Papeete, French Polynesia; and
J. P. T. Valkonen, Department of Applied Biology, University of Helsinki, Finland
ABSTRACT
Strains of Sweet potato feathery mottle virus (SPFMV; Potyvirus; Potyviridae) infecting sweet-potato (Ipomoea batatas) in Oceania, one of the worlds' earliest sweetpotato-growing areas, and in southern Africa were isolated and characterized phylogenetically by analysis of the coat protein (CP) encoding sequences. Sweetpotato plants from Easter Island were co-infected with SPFMV strains C and EA. The EA strain isolates from this isolated location were related phylogenetically to those from Peru and East Africa. Sweetpotato plants from French Polynesia (Tahiti, Tubuai, and Moorea) were co-infected with SPFMV strains C, O, and RC in different combinations, whereas strains C and RC were detected in New Zealand. Sweetpotato plants from Zimbabwe were infected with strains C and EA and those from Cape Town, South Africa, with strains C, O, and RC. Co-infections with SPFMV strains and Sweet potato virus G (Potyvirus) were common and, additionally, Sweet potato chlorotic fleck virus (Carlavirus) was detected in a sample from Tahiti. Taken together, occurrence of different SPFMV strains was established for the first time in Easter Island, French Polynesia, and New Zealand, and new strains were detected in Zimbabwe and the southernmost part of South Africa. These results from the Southern hemisphere reflect the anticipated global distribution of strains C, O, and RC but reveal a wider distribution of strain EA than was known previously.
