Identification and distribution of viruses infecting sweet potato in Kenya

Abstract

Four hundred and forty-eight symptomatic and 638 asymptomatic samples were collected from sweet potato fields throughout Kenya and analysed serologically using antibodies to Sweet potato feathery mottle virus (SPFMV), Sweet potato chlorotic stunt virus (SPCSV), Sweet potato mild mottle virus (SPMMV), Cucumber mosaic virus (CMV), Sweet potato chlorotic fleck virus (SPCFV), Sweet potato latent virus (SwPLV), Sweet potato caulimo-like virus (SPCaLV), Sweet potato mild speckling virus (SPMSV) and C-6 virus in enzyme-linked immunosorbent assays (ELISA). Only SPFMV, SPMMV, SPCSV, and SPCFV were detected. Ninety-two percent and 25% of the symptomatic and asymptomatic plants respectively tested positive for at least one of these viruses. Virus-infected plants were collected from 89% of the fields. SPFMV was the most common and the most widespread, detected in 74% of the symptomatic plants and 86% of fields surveyed. SPCSV was also very common, being detected in 38% of the symptomatic plants and in 50% of the fields surveyed. SPMMV and SPCFV were detected in only 11% and 3% of the symptomatic plant samples respectively. Eight different combinations of these four viruses were found in individual plants. The combination SPFMV and SPCSV was the most common, observed in 22% of symptomatic plants. Virus combinations were rare in the asymptomatic plants tested. Incidence of virus infection was highest (18%) in Kisii district of Nyanza province and lowest (1%) in Kilifi and Malindi districts of Coast province.

Reaction of sweet potato genotypes to sweet potato weevils (Cylas puncticollis (boheman) and Alcidodes dentipes (olivier), coleoptera: curculionidae) and viruses in Eastern Hararge, Oromiya, Ethiopia

“…also opined that sweet potato virus disease complex (SPVD), caused by dual infection with SPFMV and SPCSV, are the most important disease of sweet potato in Africa. These two viruses are the most common and damaging as reported in other East African countries Ateka et al, 2004). The presence of high prevalence of sweet potato viral disease in the Eastern Hararge is an indicative for the high population of aphid and whitefly vectors due to the favorability of the environment for these insects.…”

“…Fite et al 47 Worldwide, at least nineteen different viruses have been described in sweet potato, but only eleven (sweet potato feathery mottle, sweet potato mild mottle, SWEET potato chlorotic stunt, sweet potato chlorotic fleck virus, sweet potato caulimo like virus, sweet potato potyvirus G and sweet potato leave curl virus) (Tairo et al, 2004;Ateka et al, 2004; of these have been recognized by the International Committee on Taxonomy of Viruses (ICTV). In Ethiopia, particularly Southern Ethiopia, several SPVD have been detected.…”

Assessment of Sweet Potato Propagules for Re- infection by Various Viruses in East Kamagak Location – Homa Bay County-Kenya

“…SPFMV has a worldwide distribution and is readily spread by aphids as per Cadena Hinojosa et al [5]. Common sweet potato viruses in the country include Sweet Potato Mild Mottle Virus (SPMMV) and Sweet Potato Feathery Mottle Virus (SPFMV) (Ateka, et al [6]), thus the germplasm collected needed virus indexing to ensure that all the germplasm collected were free of viruses as they may lower the yield and quality of sweet potato. The study aimed at screening and selecting virus free germplasm.…”

Occurrence and genetic variability of partial coat protein gene of Sweet potato leaf curl virus (SPLCV) in Kenya

“…Globally, the top five sweet potato producing nations at 2014 were China, Nigeria, Uganda, Indonesia and the United Republic of Tanzania (FAOSTAT, 2015). It is an important food security crop in Kenya, and the main production areas are Western, Nyanza, Central, Coastal and Eastern regions (Ateka et al, 2004). In Kenya, virus diseases cause major losses in sweet potato production , the main diseases being Sweet potato virus disease (SPVD), a result of synergistic interaction between a potyvirus Sweet potato feathery mottle virus (SPFMV) and a crinivirus Sweet potato chlorotic stunt virus (SPCSV) (Ateka et al, 2004).…”

“…Several of these viruses occur in East Africa, including SPFMV, (genus Potyvirus), Sweet potato mild mottle virus (SPMMV, genus Ipomovirus). Others includes those in the family Closteroviridae which, includes SPCSV (genus Crinivirus), Sweet potato chlorotic fleck virus (SPCFV, genus Carlavirus) and Sweet potato leaf curl virus (SPLCV, genus begomovirus) (Ateka et al, 2004;Miano et al, 2006;Wasswa et al, 2011). SPLCV is transmitted by Bemisia tabaci or through vegetative propagation.…”