Incidence and distribution of Sweetpotato viruses and their implication on sweetpotato seed system in Malawi

Abstract

A survey was carried out in 19 districts to investigate the prevalence and distribution of sweetpotato virus disease (SPVD) and its implication on the sustainability of clean seed system in Malawi. A total of 166 leaf samples were collected and tested for the presence of 8 viruses using nitrocellulose membrane enzyme-linked immunosorbent assay (NCM-ELISA). SPVD foliar symptoms were observed in 68.42% of the surveyed districts. There were significant variations in disease incidence and severity (p < 0.001) among districts, with the highest incidence in Mulanje (28.34%). Average SPVD severity score was 3.05. NCM-ELISA detected sweet potato feathery mottle virus (SPFMV, 30.54%), sweet potato mild mottle virus (SPMMV, 31.14%), sweet potato mild speckling virus (SPMSV, 16.17%), sweet potato C-6 virus (SPC6V, 13.77%), sweet potato chlorotic stunt virus (SPCSV, 22.16%), sweet potato collusive virus (SPCV, 30.54%), sweet potato virus G (SPVG, 11.38%), cucumber mosaic virus (CMV, 7.78%) either in single or mixed infections. Data from this study indicate a significant SPVD occurrence in the country, and the consequence implications towards national sweetpotato seed system.

Sustainable sweetpotato production in the United States: Current status, challenges, and opportunities

“…Detailed studies have determined the incidence and distribution of sweetpotato viruses in several countries (Abad et al, 2007;Kwak et al, 2007;Mbewe et al, 2021;Sivaprasad & Gubba, 2013). According to Clark et al (2012), the identified viruses have been assigned to nine families as follows: Bromoviridae (1 virus), Bunyaviridae (1), Caulimoviridae (3), Closteroviridae (1), Comoviridae (1), Flexiviridae (1), Geminiviridae (15), Luteoviridae (1), and Potyviridae (9) (Table 4).…”

“…Detailed studies have determined the incidence and distribution of sweetpotato viruses in several countries (Abad et al., 2007; Kwak et al., 2007; Mbewe et al., 2021; Sivaprasad & Gubba, 2013). According to Clark et al.…”

Social incentives as nudges for agricultural knowledge diffusion and willingness to pay for certified seeds: Experimental evidence from Uganda

“…Recycled and locally sourced seed are often heavily infested with pests and diseases ( Mbewe et al, 2021 ). Planting diseased low-quality seed can result in high yield penalties and welfare-reducing effects in developing-country agriculture ( Mann and Warner, 2017 , Okello et al, 2017 , Wossen et al, 2020 ).…”

Preliminary Study on Evaluation of Sweet Potato Genotypes for Resistance to Sweet Potato Virus Disease (SPVD)

“…These hindrances prevail both in the field and post-harvest (Abrham et al, 2021;Ngailo et al, 2013;Fuglie, 2007). Among the diseases, SPVD has been reported as the most important sweet potato disease in most of the tropical regions in Africa, and perhaps across the globe (Mbewe et al, 2021;Mukasa et al, 2006). SPVD can cause over 90 % yield loss (in terms of both root and foliage) among susceptible genotypes if not managed (Jones, 2021;Ngailo et al, 2013;Gutierrez et al, 2003).…”

“…SPVD can cause over 90 % yield loss (in terms of both root and foliage) among susceptible genotypes if not managed (Jones, 2021;Ngailo et al, 2013;Gutierrez et al, 2003). SPVD is caused by a dual infection and synergistic relationship between sweet potato feathery mottle potyvirus (SPFMV) and sweet potato chlorotic stunt crinivirus (SPCSV) (Mbewe et al, 2021;Mukasa et al, 2006;Karyeija et al, 2000). SPFMV is a member of potyviridae family.…”