White-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), is known as a long-range migratory pest in Asia. Although exact primary source of S. furcifera in Korea remains unknown. We used twelve microsatellite markers (SSR) to analyze the population genetic structure of the pest. We collected S. furcifera from Asia in 2012 (Korea, Laos, Nepal, Thailand, Vietnam and four different sites of Bangladesh), 2013 (China, Nepal, Thailand, two different sites of Bangladesh, and fifteen different sites of Korea), and 2014 (four different sites of China and ten different sites of Korea). To verify the genetic variance, we used STRUCTURE program to obtain structure analysis of K and K showed in three components in genetic clustering. Result in sample 2012, similar genetic structure showed in Korea and Vietnam. In 2013 and 2014, various genetic structure revealed in different sites of Korea and Asian population genetic structure appeared as on large panmictic population. Furthermore, we tested migration pathway to see the probable source and reciplent populations of first generation migrants in S. furcifera. In 2012, Laos, Nepal, Thailand, Vietnam and four different sites of Bangladesh showed the potential source of S. furcifera. In 2013, we observed S. furcifera in Korea was more likely originated from Nepal and Bangladesh. Various migration pathway showed in fifteen different sites of Korea as panmictic population. Lastly in 2014, the migration pathway indicated that S. furcifera migrates from China to Korea. Seemingly, S. furcifera in Asia display as large panmictic population and more study is acquire to verify the origin source.

White-backed planthopper, Sogatella furcifera (Horvath) (Hemiptera: Delphacidae), has been a serious migratory pest in Korea. It is important to figure out the migration route and gene flow of S. furcifera. Microsatellite marker (SSR) shows high efficiency as molecular markers. Unfortunately, various microsatellite marker of S. furcifera has not been developed to see genetic diversity. S. furcifera samples were collected from Vietnam, Laos and three different sites of Bangladesh in 2012. We extracted DNA by using QIAamp DNA Mini Kit and ran next generation DNA sequencer (NGS) Roche 454 to develop a new microsatellite marker. Roughly, about 18 singleton primers and 14 contigs primers were found. We will test these primers with S. fucifera DNA samples, and figure out the accurate new microstatellite marker.

Population genetics is the study of genetic constitution of Population across space and over time. Population genetics plays a pivotal role in characterizing dispersal behavior of insects and provides important clues to questions in the field of insect behavior and ecology. Understanding dispersal behavior of insects is of important issue not only for academic interests but also for application purposes including management and eradication. Dispersal is one of major evolutionary forces that can influence genetic variation of population. Dispersal is mostly driving genetic homogenization of diverging populations. Moreover, understanding dispersal pattern and capacity of insects is a key component for designing effective management and resistance management strategies of many insect pests since dispersal ability determines the spread rate of disease and resistance gene. The capability of predicting insect movement therefore is an essential component of agricultural production management systems. Here I introduce application of population genetics to insect dispersal study with the case studies of three agricultural insect pests, cotton boll weevil (Anthonomus grandis), Western con rootworms (Diabrotica vergifera) and European corn borer (Ostrinia nubilalis). These insects all are invasive and major pests of crops of U.S.A during the last ~100 years.

The Nilaparvata lugesn(BPH) and Laodelphax striatellus(SBPH) are major insect pests of rice in Korea. These BPHs migrate from China to Korea, but we have not exactly known about the route of long-distance migration of them. Molecular markers including microsatellite will be critical to asses gene flow in relation to geographical distance. In our work several microsatellite markers were developed for basic population genetic analysis of BPH and SBPH. Among each 21 microsatellite markers in BPH and SBPH, we could select 6 markers for BPH and 2 markers for SBPH as putative markers for analysis of population genetics. Others are further investigated for the possibility as markers. Development of polymorphic microsatellite loci are final stage of our work. But for good microsatellite markers to population genetics, we should do more experiments. Our work for development of microsatellites should facilitate the study of future population genetics of BPH and SBPH, and eventually elucidate the route of BPH and SBPH migration to Korea.

Ramie (Boehmeria nivea L. Gaudich.) is a hardy perennial herbaceous plant of the Urticaceae family and has been grown as a fiber crop in several countries including Korea for many centuries. Ramie leaves also have been traditionally used as a major ingredient of a type of rice cake called ‘Song-pyun’ in the Southwest area of Korea, especially Yeong-Gwang province. Despite its economic importance, the molecular genetics of ramie have not been studied in detail yet. Genetic resources of ramie were widely collected from domestic local sites by Bioenergy Crop Research Center (RDA) and Yeong-Gwang Agricultural Technology Center. For the systematic and efficient management of the genetic resources, we developed microsatellite molecular markers of ramie. To do this, we generated microsatellite-enriched genomic DNA libraries using magnetic bead hybridization selection method. 216 contigs containing microsatellite repeat motif were generated using nucleotide sequences of 376 clones from the libraries. Primer sets were designed from the flanking sequences of the repeat motif. Finally, we selected 26 microsatellite markers, possibly showing polymorphism among the genetic resources. Results on the genotype analysis of the ramie genetic resources using the microsatellite markers will be presented.

A new spray chrysanthemum (Dendranthema grandiflorum) cultivar Peak was bred by crossing between GrandPink and Relance. Its growth and flower characteristics were investigated from 2002 to 2004 by shading culture in summer andretarding culture in spring.