Abstract:
Globally, Sweet potato feathery mottle virus (SPFMV) and Sweet potato chlorotic stunt virus (SPCSV) occur
frequently and in combination cause sweetpotato virus disease (SPVD). Many viral diseases are economically
important and negatively impact the production and movement of germplasm across regions. Rapid detection of
viruses is critical for effective control. Detection and quantification of viruses directly from sweetpotato remains
a challenge. Current diagnostic tests are not sensitive enough to reliably detect viruses directly from the plant or
require expensive laboratory equipment and expertise to perform. We developed a simple and rapid loop-
mediated isothermal amplification (LAMP) assay for the detection of SPFMV, SPCSV and begomoviruses related
to sweet potato leaf curl virus (SPLCV). Laboratory validation recorded 100 % diagnostic sensitivity for all the
three viruses. The LAMP assays were customized for field testing using a lyophilized thermostable isothermal
master mix in a ready-to-use form that required no cold chain. The average time to positivity (TTP) was: SPFMV
5 30 min, SPCSV 15–43 min s and begomoviruses 28 45 mins. LAMP on-site testing results were comparable to
PCR and RT-PCR confirmatory laboratory tests. The LAMP assay is a powerful tool for rapid sweetpotato virus
detection at a reasonable cost and thus could serve as quality control systems for planting materials.
