East Asian Passiflora virus.

East Asian Passiflora virus (EAPV) is a potyvirus that infects passion fruit Passiflora edulis. It can produce mosaic symptoms on leaves and severely malformed and woody fruits (Iwai et al., 1996). It is currently found in Japan, Taiwan and Peninsular Malaysia, although its global distribution is not yet clear.

Cowpea aphid-borne mosaic virus.

Cowpea aphid-borne mosaic virus (CABMV) is a potyvirus capable of infecting many species in the family Fabaceae, and most strains also infect members of the Amaranthaceae, Chenopodiaceae, Cucurbitaceae, Laminaceae, Passifloraceae and Solanaceae. Its main hosts are cowpea and passionfruit, and along with East Asian Passiflora virus and passionfruit woodiness virus it induces passionfruit woodiness in passionfruit. CABMV occurs worldwide but is a particularly major and widespread disease of cowpea in Africa. The nature and severity of the symptoms induced by CABMV are extremely variable, and vary with host cultivars, virus strain and the time of infection. Symptoms can include various mosaics, mottling, interveinal chlorosis and vein-banding. Complete loss of cowpea crops has been reported from Nigeria, and CABMV is one of the main limiting factors to passionfruit yield in South America and Africa.

Characterization and Distribution of a Potyvirus Associated with Passion Fruit Woodiness Disease in Uganda

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. Enzymelinked 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.