Development of a simple and accurate molecular tool for Spodoptera
frugiperda species identification using LAMP
Abstract
The fall armyworm, Spodoptera frugiperda is a native species in the
Americas. However, nowadays it is one of the most serious invasive
lepidopteran pests in African and Asian countries. S. frugiperda has
been spread very quickly after the first outbreak was reported in many
countries. Based on mt genome sequence alignment, S. frugiperda specific
sequence region was identified in tRNAs coding region between NADH
dehydrogenase, ND3 and ND5. By using this unique region, species
diagnostic primers were designed and applied in LAMP (lamp loop mediated
isothermal amplification) assay as well as conventional PCR to identify
the field-collected samples of S. frugiperda. Optimal incubation
condition of LAMP assay was 61℃ for 90 minutes with 4 LAMP primers, and
additional loop primer increased the amplification efficiency. Also,
wide range of DNA concentration responded in LAMP assay and minimum
detectable DNA concentration was 10 pg. This LAMP assay was also applied
in DNA releasing technique from larval and adult sample, without DNA
extraction, 95℃ incubation for five minutes of the tissue sample. This
new molecular diagnostic method is easy to use and accurate. It possibly
applied in intensive field monitoring of S. frugiperda and its
ecological studies.