Development of a Species Diagnostic Molecular Tool for an Invasive Pest, Mythimna loreyi, Using LAMP
Highland Agriculture Research Institute, National Institute of Crop Science, Rural Development Administration, Pyeongchang 25342, Korea
Crop foundation Division, National Institute of Crop Science, Rural Development Administration, Wanju 55365, Korea
Program of Applied Biology, Division of Bio-resource Sciences, College of Agriculture and Life Science, Kangwon National University, Chuncheon 24341, Korea
Author to whom correspondence should be addressed.
Received: 20 October 2020 / Revised: 15 November 2020 / Accepted: 17 November 2020 / Published: 19 November 2020
Mythimna loreyi is a serious pest of grain crops and reduces yields in maize plantations. M. loreyi is a native species in East Asia for a long time. However, this species has recently emerged as a migration (or invasive from other Asian countries) pest of some cereal crops in Korea. Little is known about its basic biology, ecology, and it is difficult to identify the morphologically similar species, Mythimna separate, which occur at the cornfield in the larvae stage. Species diagnosis methods for invasive pests have been developed and utilized for this reason. Currently, the molecular biology method for diagnosing M. loreyi species is only using the mtCO1 universal primer (LCO1490, HCO2198) and process PCR and sequencing to compare the degree of homology. However, this method requires a lot of time and effort. In this study, we developed the LAMP (loop-mediated isothermal amplification) assay for rapid, simple, and effective species diagnosis. By analyzing the mitochondrial (mt) genome, the species-specific sequence was found at the coding region of the NADH dehydrogenase subunit 5 gene. A broad range of DNA concentration was workable in LAMP assay, in which the minimum detectable DNA concentration was 100 pg. DNA releasing method was applied, which took five minutes of incubation at 95 °C without the DNA extraction process, and only some pieces of tissue from larvae and adult samples were needed. The incidence of invasive pests is gradually diversifying. Therefore, this simple and accurate LAMP assay is possibly used in the intensive field monitoring for invasive pests and integrated management of Mythimna loreyi.