V. Aritua, Julius Kuehn Institute, Federal Research Centre for Cultivated Plants (JKI), Institute of Epidemiology and Pathogen Diagnostics, Braunschweig, Germany; National Agricultural Biotechnology Center, Kawanda Agricultural Research Institute, Kampala, Uganda; and Department of Plant Pathology, Kansas State University, Manhattan 66506 USA;
E. Barg, JKI, Germany;
E. Adipala, Department of Crop Science, Makerere University, Uganda;
R. W. Gibson, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK; and
D. E. Lesemann and
H. J. Vetten, JKI, Germany
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Accepted for publication 30 September 2008.
Sweet potato chlorotic fleck virus (SPCFV) has recently been classified as a putative new member of the genus Carlavirus (family Flexiviridae) on the basis of its molecular properties. In this study, SPCFV was characterized in terms of host range, physical and biological characteristics, and genetic variability. In addition to sweet potato, SPCFV infected some plant species in the families Convolvulaceae, Chenopodiaceae, and Solanaceae. Limited numbers of virus particles were observed in the assimilation parenchyma cells of infected plant tissues; some cells had a distorted and enlarged endoplasmic reticulum though without any cytoplasmic and amorphous inclusions. The normal length of SPCFV particles was determined to be approximately 800 nm. In enzyme-linked immunosorbent assays, polyclonal antibodies raised against purified SPCFV virions were able to detect the virus in infected sweet potato and indicator plant tissues. In immunoelectron microscopy, SPCFV particles were all strongly decorated when reacted with homologous antiserum. Comparison of the 3′ terminal part of the genome of a range of geographically diverse isolates revealed a high level of genetic diversity. The amino acid sequence identity in the coat protein and the nucleic acid binding protein ranged from 89 to 99.7% and from 75.9 to 99.2%, respectively. Phylogenetic analysis of both proteins showed a geographically associated clustering into two genogroups.
© 2009 The American Phytopathological Society