본 연구는 한국 희귀종인 한란의 보전을 위하여 ISSR 표지자를 이용한 유전변이와 분화 및 공간적 유전구조를 분석하였다. 분석된 유전다양성(Species level: h=0.303, S.I=0.389)은 근연종과 다른 희귀 종에 비해 높은 유전변이를 나타내었다. 또한 유전자형 다양성(Species level: GN/N=0.884, D=0.996) 역시 높게 나타나 주로 타가수정이 이루어지는 것으로 조사되었다. 한편, 소집단 A와 B 간에 분화정도 는 23%로 소집단 간의 인접거리를 고려했을 때, 집단 내에서도 분포의 위치에 따라 분화가 발생하고 있었다. 높은 수준의 유전다양성과 분화의 발생요인을 고려했을 때, 과거 외부에서 지속적으로 유입된 한란 개체로부터의 영향과 매개충의 역할이 주요한 원인으로 추정되었다. 소집단의 공간적 유전구조 분 석에서 A는 9m, B는 6m 이내에 분포하는 개체들 간에 유전적 유사성이 높은 것으로 나타났다. 이 결 과를 바탕으로 한란의 현지 외 보전을 위한 표본 추출 시 최소 9m 이상의 간격을 유지하는 것을 제안 하는 바이다.

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.

The bumblebee, Bombus ignitus (Hymenoptera: Apidae), is a valuable natural resource that is widely utilized for greenhouse pollination in South Korea. Understanding the magnitude of genetic diversity and geographic relationships is of fundamental importance for long term preservation and utilization. As a first step, we sequenced a partial COI gene of mitochondrial DNA (mtDNA) corresponding to the “DNA barcode” region and the complete internal transcribed spacer 2 (ITS2) of nuclear ribosomal DNA from 88 individuals collected in nine South Korean localities. The complete ITS2 sequences were longest among known insects, ranging in size from 2,034 bp ~ 2,052 bp, harboring two duplicated 112-bp long repeats. The 658-bp long mtDNA sequences provided only six haplotypes with a maximum sequence divergence of 0.61% (4 bp), whereas the ITS sequences provided 84 sequence types with a maximum sequence divergence of 1.02% (21 sites). The combination of the current COI data with those of published data suggest that the B. ignitus in South Korea and China are genetically a large group, but those in Japan can be roughly separated into another group. Overall, a very high per generation migration ratio, a very low level of genetic fixation, and no discernable hierarchical population were found to exist among the South Korean populations of B. ignitus, which suggests panmixia. This finding is consistent with our understanding of the dispersal capability of the species.

The ant species, Vollenhovia emeryi, is distributed in Far East. The species can be divided into two major groups by their wing morphology of reproductives: short-winged and long-winged. A nationwide survey of the species was conducted for analyzing the mitochondrial haplotype diversity and genetic population structure. We collected 91 samples from 40 locations. A total of the 1239 bp partial COI (cytochrome C oxidase 1) region was used for the analyses. We found the total of 21 haplotypes. The mitochondrial haplotypes may correspond to the wing morphology. The genetic population structure examined potential geographic barriers of gene flow such as distance, mountains, rivers and plains which are non-mountain areas to prevent dispersal through mountain range. The result implied that no barriers considered in this study affected differently gene flow. Therefore, the behavioral characteristics of the ant may be the causal constraint of its genetic exchange.

The soybean aphid, Aphis glycines Matsumura, was recently introduced from Asia into North America (NA) where it has become a serious pest of soybeans. This invasive pest has rapidly spread throughout the midwestern United States and southern Canada since 2000. We examined 585 individuals obtained from 23 different collections in USA, Korea, China, and Japan using eight microsatellite loci. Based on analysis of multilocus genotype, gene diversity and number of alleles in NA were averaging 0.40 and 2.70, whereas in Asia averaging 0.55 and 4.32, respectively. The factorial correspondence analysis displayed that some Korean populations were closely related to the NA populations. Structure analysis resulted in two conspicuous clusters, NA and Asia, as the most likelihood number of clusters (K). Bayesian assignment tests revealed that Osan and Milyang populations were most likely assigned to the NA populations. Bottleneck test did not show significance of genetic bottleneck in all populations. We also discuss the invasive history of the soybean aphid in light of population genetics.

In crop breeding program, information about genetic dissimilarity on breeding resources is very important to corroborate genealogical relationships and to predict the most heterozygotic hybrid combinations and inbred breeding. This study aimed to evaluate the genetic variation in Kenyan sunflower breeding lines based on simple sequence repeat (SSR). A total of 83 alleles were detected at 32 SSR loci. The allele number per locus ranged from 2 to 7 with an average of 2.7 alleles per locus detected from the 24 sunflower accessions and the average value of polymorphic information contents (PIC) were 0.384. A cluster analysis based on the genetic similarity coefficients was conducted and the 24 sunflower breeding resources were classified into three groups. The principal coordinates (PCoA) revealed 34% and 13.38% respectively, and 47.38% of total variation. It was found that the genetic diversity within the Kenyan sunflower breeding resources was narrower than that in other sunflower germplasm resources, suggesting the importance and feasibility of introducing elite genotypes from different origins for selection of breeding lines with broader genetic base in Kenyan sunflower breeding program.

We collected 32 maize inbred lines from eastern cereal and oilseed research center in Canada to develop new maize varieties. We also evaluated genetic diversity, genetic relationships, and population structure using 35 SSR markers. A total of 269 alleles were revealed in 35 loci with an average of 7.69 and a range between 3 and 15 alleles per locus. The genetic diversity values varied from 0.176 to 0.889 with an average of 0.691. The polymorphic information content varied from 0.171 to 0.879 with an average of 0.659. Population structure analysis indicated that 32 Canadian maize inbred lines comprised four major groups and one admixed group based on a membership probability threshold of 0.80. The four major groups contained 13, 2, 5 and 2 maize inbred lines, respectively. From genetic relationships analysis, the all inbred lines were divided into three main groups at 26% genetic similarity. Group I included 22 inbred lines, and Group II included 9 inbred lines. Group III consist of only one inbred line. The results in this study would be useful for the improvement and development of new cultivars, planning crosses for hybrids or development of inbred line in maize breeding program

Understanding the genetic variation among landrace collections is important for crop improvement and utilization of valuable genetic resources. The present study was carried out to analyse the genetic diversity and associated population structure of 621 foxtail millet accessions of Korean landraces using 22 EST-SSR markers. A total of 121 alleles were detected from all accessions with an average of 5.5 alleles per microsatellite locus. The average values of gene diversity, polymorphism information content, and expected heterozygosity were 0.518, 0.594, and 0.034, respectively. Following the unweighted neighbor-joining method with arithmetic mean based clustering using binary data of polymorphic markers, the genotypes were grouped into 3 clusters, and population structure analysis also separated into 3 populations. Principal coordinate analysis (PCoA) explained a variation of 13.88% and 10.99% by first and second coordinates, respectively. However, in PCoA analysis, clear population-level clusters could not be found. This pattern of distribution might be the result of gene flow via germplasm exchanges in nearby regions. The results indicate that these Korean landraces of foxtail millet exhibit a moderate level of diversity. This study demonstrated that molecular marker strategies could contribute to a better understanding of the genetic structure in foxtail millet germplasm, and provides potentially useful information for developing conservation and breeding strategies.

Assessing genetic diversity, population structure, and linkage disequilibrium is important in identifying potential parental lines for breeding programs. In this study, we assessed the genetic and phenotypic variation of 174 normal maize (Zea mays) inbred lines and made association analyses with respect to nine agronomical traits, using 150 simple sequence repeats (SSR). From population structure analysis, the lines were divided into three groups. Association analysis was done with a mixed linear model and a general linear model. Twenty one marker-trait associations involving 19 SSR markers were observed using the mixed model, with a significance level of P<0.01. All of these associations, as well as 120 additional marker-trait associations involving 77 SSR markers, were observed with the general model. Two significant marker-trait associations (SMTAs) were detected at P ≤ 0.0001. In the mixed linear model, one locus was associated with water content, two loci were associated with 100-kernel weight, setted ear length, ear thickness and stem thickness; three loci were associated with ear height, four loci were associated with total kernel weight and five loci were associated with plant height. These results should prove useful to breeders in the selection of parental lines and markers.

소나무의 유전다양성과 유전구조를 추정하기 위해 9개의 ESTP 표지를 13개 소나무 집단에 적용하였다. 소나무 집단의 유전다양성은 관찰된 대립유전자 수(A)가 2.2개, 유효 대립유 전자 수(Ae)가 1.8개, 다형적 유전자좌 비율(P)이 98.8%, 이형접 합도 관찰치(Ho)가 0.391, 이형접합도 기대치(He)가 0.402로 나 타났다. 안강과 강릉 집단을 제외한 11개 집단이 하디-바인베르 그 평형을 만족하였다. 집단간 유전분화도(FST)는 0.057으로, 동위효소나 nSSR 표지분석 결과보다 강하게 나타났다. 군집분 석에서 집단의 유전적 거리와 지리적 분포간에 뚜렷한 연관성 은 확인할 수 없었으며, 집단의 유전분화와 지리적 인접성도 상 관이 없는 것으로 나타났다(Mantel 검증, r = 0.017, P = 0.344). 유전자좌에 대한 FST-outlier 분석을 실시한 결과, 빈도 주의 방법에서는 FST 값이 신뢰하한 이하인 3개 유전자좌와 신 뢰상한 이상인 3개 유전자좌가 특이값으로 추정되었고, 베이즈 방법에서는 3개 유전자좌들만 특이값으로 확인되었다. 두 방법 에서 공히 특이값으로 판정된 3개 유전자좌(sams2+AluⅠ, sams2+RsaⅠ, PtNCS_p14A9+HaeⅢ)중 sams2 표지에서 유래 된 2개 유전자좌는 balancing selection의 영향을 받는 것으로 추정되었다.

Soybean (Glycine max L.) is crucial legume crop as source of high quality vegetable protein and oil, and Korea is regarded as a part of center of soybean origin. To expand the information of conserved genetic diversity, we analyzed the genetic variability of soybean collection mainly introduced Korean accessions using 75 microsatellite markers. A total of 1,503 alleles with an average value of 20.0 alleles were detected among 644 accessions. Korean collection revealed average allele number of 13.4 while Chinese, Japanese and Southeast Asian accessions showed 9.0, 5.4 and 6.5 mean alleles, respectively. Especially, Korean accessions showed more number of private allele per locus as 3.4 contrary to other geographical groups. The mean expected heterozygosity and polymorphic information content was 0.654 and 0.616, respectively, and expected heterozygosity values were not significantly distinguished according to the geographical groups. The phylogenetic dendrogram and deduced population structure based on DNA profiles of 75 SSR loci showed Korean accessions formed distinct gene pool against Chinese accessions, and could be divided into five subpopulations. Korean soybean accessions have specific genetic diversity and might be serve the valuable alleles for bio-industry as a part of the center of soybean origin.

We investigated the genetic diversity and structure of the 239 fixed lines with 47 simple sequence repeat (SSR) and 109 NGS-generated SNP markers evenly distributed in B. rapa genome. Phylogenetic analysis classified the vegetable fixed lines to four subgroups, with the three types forming a separate and relatively farther cluster. Population structure analysis identified four sub-populations corresponding to geographic origin and morphological traits, and revealed extensive admixture. The vegetable B. rapa fixed lines successfully developed in our study would be valuable materials for multinational B. rapa diversity resources establishment. Understanding the genetic diversity and population structure could be useful for utilization of the representing genetic variation and further genetic and genomic analysis.

Capsicum diversity is getting lower in modern crops because of the genetic erosion. In Capsicum, breeders have been mainly focused on agriculturally important traits such as disease resistances, high yield and pungency. This narrow breeding pool hampered to develop improved cultivars. It has become a hot issue to conservation of genetic diversity and exploitation of wild germplasm in Capsicum. However, although a large number of accessions are maintained in Capsicum germplasm collections, their use for crop improvement is limited by the scarcity of information on genetic diversity, population structure and proper phenotypic assessment. The identification of representative and manageable subset of accessions would facilitate access to the diversity available in large collections. A genome wide germplasm characterization using molecular markers can offer reliable tools for adjusting the quality and representativeness of core samples. We investigated patterns of molecular diversity at 48 single nucleotide polymorphisms (SNPs) in 4056 accessions from 11 Capsicum species from 89 different countries. Using these genetic variations and 32 different morphological traits, 250 core set was selected in whole Capsicum germplasm. The core collection could be a primary source for distributing germplasm to pepper breeders and other national programs as well as for evaluation

Amaranth (Amaranthus sp. L.) is an important group of plants that includes grain, vegetable, and ornamental types. Centers of diversity for Amaranths are Central and South America, India, and South East Asia, with secondary centers of diversity in West and East Africa. The present study was performed to determine the genetic diversity and population structure of 75 amaranth accessions: 65 from South America and 10 from South Asia as controls using 14 SSR markers. Ninety-nine alleles were detected at an average of seven alleles per SSR locus. Model-based structure analysis revealed the presence of two subpopulations and 3 admixtures, which was consistent with clustering based on the genetic distance. The average major allele frequency and polymorphic information content (PIC) were 0.42 and 0.39, respectively. According to the model-based structure analysis based on genetic distance, 75 accessions (96%) were classified into two clusters, and only three accessions (4%) were admixtures. Cluster 1 had a higher allele number and PIC values than Cluster 2. Model-based structure analysis revealed the presence of two subpopulations and three admixtures in the 75 accessions. The results of this study provide effective information for future germplasm conservation and improvement programs in Amaranthus.

For the study of population genetic structure with mtDNA, it is essential to measure genetic diversity at each mtDNA regions. Also, to evaluate the variation according to the each region should follow as well as to see if there are differences. In this study, we delved into the variations and dendrogram among samples of seven mtDNA regions (NDⅡ, NDⅤ, NDⅣ, NDⅣL, NDⅥ, NDⅠ, 12SrRNA) from wild Pacific abalone, Haliotis discus hannai collected in Yeosu, Korea. The region with the highest genetic variation was NDⅣ region (Haplotype diversity = 1.0000, Nucleotide diversity = 0.010823) with two to five times higher variation than the others. Furthermore, the study to see if there is a difference between the regions of samples showed that similar aspects of dendrogram in NDⅡ and NDⅠ(divergence of 90% and 87%), which forms a group with hd4, 7, 8 and 10 at bootstrap support, based on 1000 replications. Also, pair-wise FST between clusters within the regions showed high values; 0.4061 (P=0.0000), 0.4805 (P=0.0000) respectively. Therefore we can infer that it is the most efficient and accurate way to analyze the region of NDⅣ with the highest variation in addition to the regions of NDⅡ and NDⅠ, which formed clusters with high bootstrap value, for study of population genetic structure in this species.

Our study is performed to confirm the level of genetic diversity and population structure with 80 maize inbred lines (40 waxy inbred lines and 40 flint inbred lines) and to explain the genetic basis of agronomic traits using an association mapping. The 200 SSR loci are confirmed a total of 1,610 alleles in total 80 maize inbred lines. The average number of alleles per locus was 8.05. The average GD was 0.72. The average PIC value was 0.68. The average MAF was 0.40. Population structure was revealed for K=2. Total 80 maize inbred lines were divided by groups I, II and admixed group. The 14 waxy inbred lines were assigned to group I. The 45 inbred lines include 5 waxy inbred lines and 40 flint inbred lines were contained to group II. The 21 waxy inbred lines were contained in the admixed group with lower than membership threshold 0.8. Association mapping between 200 SSR markers and 10 phenotypic traits of waxy/flint maize inbred lines were performed by Q GLM and Q+K MLM. In significant level at 0.01, 72 SSR markers were associated with 10 phenotypic traits using Q GLM. The 4 marker-trait association were detected in Q+K MLM. The results derived from this study will be used for designing efficient new maize breeding programs.

Amaranths (Amaranthus sp.) are cosmopolitan and include grain, vegetable, ornamental and weed types. Forteen simple sequence repeat (SSR) markers were used to analyze the genetic diversity of 59 accessions of cultivated amaranth from Asian countries. A total of 63 alleles were detected with an average of 4.5 per locus. The averaged values of gene diversity and polymorphism information content (PIC) were 0.35 and 0.33, respectively. Alleles per locus in accessions from South Asia was 4.35, whereas 2.93 and 3.79 alleles per locus were found in Nepal and India, respectively. The mean gene diversity in Central Asia and East Asia was 0.36 and 0.28, respectively, whereas the mean PIC values were 0.27 and 0.22, respectively. The genetic diversity and PIC of the India amaranths were higher than that of other Asian countries. The model-based structure analysis revealed the presence of three subpopulations, which was basically consistent with clustering based on genetic distance. An AMOVA analysis showed that the between-population component of genetic variance was less than 56.16% in contrast to 43.84% for the within-population component. The overall FST value was 0.56, reflecting genetic differentiation within Asian amaranths. These findings could be used for designing effective breeding programs aimed at broadening the genetic bases of commercially grown varieties.