Partial characterization of Sweetpotato Feathery Mottle Virus infecting Ipomoea batatas in Burkina Faso. Molecular characterization of SPFMV in Burkina Faso

SPFMV in Burkina FasoProblem statement: Sweetpotato (Ipomoea batatas) production in Sub-Saharan Africa is severely affected by several viral diseases, including Sweetpotato feathery mottle virus (SPFMV), but the aetiology of viral symptoms on sweetpotato is rarely established in most countries of this region. The occurrence of SPFMV in Burkina Faso was investigated in order to aid efforts to increase the production of sweet potato. Approach: Field surveys were undertaken and leaf samples were collected from symptomatic and asymptomatic plants. SPFMV was detected in collected samples by enzyme linked-immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR). T-coffee and FastTree software were used to identify the sampled viral strains. Results: SPFMV was successfully detected by ELISA in 83.2% of which 84.1 for symptomatic samples and 15.9 for asymptomatic samples. The virus was found in samples from 21 sampling locations in all the major sweetpotato-growing areas of Burkina Faso. The CP gene from thirteen isolates was amplified by RT-PCR and sequenced. Phylogenetic analyses indicated that all isolates belonged to either the ‘Russet Crack’ (RC) or the ‘Ordinary’ (O) strain of SPFMV. Conclusion: This first study of SPFMV in Burkina Faso indicates widespread occurrence of the virus in sweetpotato and suggests a need for further investigations into disease epidemiology. The presence of SPFMV in both symptomatic and asymptomatic plants in the major sweetpotato-growing areas of the country indicates an urgent need for a breeding programme focused on generating new SPFMV-resistant varieties for Burkina Faso.Key words: SPFMV, Potyvirus, ELISA, RT-PCR, Sweetpotato