Abstract:
Sweetpotato is an important food crop in global production. However, sweetoptato
viruses pose a threat to sustainable agriculture and cause significant economic loss.
More than 30 viruses have been reported to date, with sweet potato feathery mottle
virus (SPFMV) and sweet potato chlorotic stunt virus (SPCSV) occurring frequently
and in combination, causing sweetpotato virus disease. The detection of viruses
directly from sweetpotato is still a challenge, and efforts are being made toward this
front. Therefore, rapid detection of viruses is critical for effective control. Current
diagnostic tests are not sufficiently sensitive to reliably detect viruses directly from
sweetpotato and require expensive laboratory equipment and a high level of skilled
experience. Loop-mediated isothermal amplification (LAMP) is sensitive and spe
cific for both DNA/RNA amplification; it is affordable and its characteristics make it
potentially suitable for on-site testing. LAMP assays have been developed for sev
eral sweetpotato viruses: SPCSV, SPFMV, and sweet potato leaf curl virus (and
related sweepoviruses). Laboratory validation showed a 100% diagnostic sensitiv
ity for all three viruses. The LAMP on-site testing results were comparable to those
of polymerase chain reaction and reverse transcriptase polymerase chain reaction
confirmatory laboratory tests. Interlab validation and packaging into affordable kits
will ensure high adoption in sub-Saharan Africa. The LAMP assay can be used for
field surveys and monitoring the phytosanitary status of pre-basic seed production in
quarantine or certification program. This guarantees pathogen-free planting material
enters the seed system. We discuss opportunities for LAMP as a diagnostic assay for
the rapid detection of sweetpotato viruses and its adoption as a quality control system
for planting materials
