M. Ochwo-Ssemakula, Department of Agricultural Production, Makerere University, P.O. Box 7062, Kampala, Uganda;
T. Sengooba, International Food Policy Research Institute, P.O. Box 28565, Kampala, Uganda;
J. J. Hakiza, National Agricultural Research Laboratories, Kampala, Uganda;
E. Adipala, Regional Universities Forum for Capacity Building in Agriculture, P.O. Box 7062, Kampala, Uganda;
R. Edema, Department of Crop Science, Makerere University, Kampala, Uganda;
M. G. Redinbaugh, USDA, ARS Corn and Soybean Research Unit, and Department of Plant Pathology, The Ohio State University, OARDC, 1680 Madison Avenue, Wooster, OH 44691, USA;
V. Aritua, National Agricultural Biotechnology Centre, National Agricultural Research Laboratories, P.O. Box 7065, Kampala, Uganda, and Department of Plant Pathology, Kansas State University, 4024 Throckmorton Plant Sciences Center, Manhattan, KS 66506, USA; and
S. Winter, Plant Virus Department, Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Messeweg 11/12, Braunschweig 38104, Germany
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Accepted for publication 15 September 2011.
This article describes the incidence and etiology of a viral disease of passion fruit in Uganda. Symptoms, including those characteristic of passion fruit woodiness disease (PWD), were observed on 32% of plants in producing areas. Electron microscopic observations of infected tissues revealed flexuous filaments of ca. 780 nm. Enzyme-linked immunosorbent assays indicated a serological relationship with Cowpea aphid-borne mosaic virus (CABMV) and Passion fruit ringspot virus (PFRSV). In host range studies, only species in the families Solanaceae and Chenopodiaceae were susceptible, and neither Vigna unguiculata nor Phaseolus vulgaris became infected. Coat protein (CP) gene sequences of eight isolates exhibited features typical of potyviruses and were highly similar (88 to 100% identity). However, the sequences had limited sequence identity with CP genes of two of the three potyviruses reported to cause PWD: East Asian Passiflora virus and Passion fruit woodiness virus (PWV). Deduced amino acid sequences for the CP of isolates from Uganda had highest identity with Bean common mosaic necrosis virus (BCMNV) (72 to 79%, with evolutionary divergence values between 0.17 and 0.19) and CABMV (73 to 76%, with divergence values between 0.21 and 0.25). Based on these results and in accordance with International Committee for Taxonomy of Viruses criteria for species demarcation in the family Potyviridae, we conclude that a previously unreported virus causes viral diseases on passion fruit in Uganda. The name “Ugandan Passiflora virus” is proposed for this virus.
© 2012 The American Phytopathological Society