• Title/Summary/Keyword: Natural populations

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Stock Characterization of the Fleshy Prawn (Penaeus chinensis) in the Yellow Sea by Intraspecific Sequence Variation of the Cytochrome c Oxidase Subunit I Gene

  • HWANG Gyu-Lin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.6
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    • pp.876-881
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    • 1996
  • To determine the amount of genetic variation among populations of Penaeus chinensis (Osbeck) in the Yellow Sea, 342 bp region of the mitochondrial cytochrome c oxidase subunit I gene was amplified and sequenced. Six haplotypes, which differ by from one to four nucleotide sustitutions, were detected from 34 individuals of 4 populations examined. Mean sequence divergence between pairs of haplotypes was $0.68\%$. Most individuals from 4 populations were shared by the most common genotype. This genotype was distributed evenly in the Korean and Chinese populations. This result is in accordance with findings observed using RFLPs analysis of mtDNA (Hwang et al., 1997). Therefore, it is suggested that P. chinensis should be treated as one unit stock in the Yellow Sea.

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Effective Population Size of Korean Populations

  • Park, Leeyoung
    • Genomics & Informatics
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    • v.12 no.4
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    • pp.208-215
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    • 2014
  • Recently, new methods have been developed for estimating the current and recent changes in effective population sizes. Based on the methods, the effective population sizes of Korean populations were estimated using data from the Korean Association Resource (KARE) project. The overall changes in the population sizes of the total populations were similar to CHB (Han Chinese in Beijing, China) and JPT (Japanese in Tokyo, Japan) of the HapMap project. There were no differences in past changes in population sizes with a comparison between an urban area and a rural area. Age-dependent current and recent effective population sizes represent the modern history of Korean populations, including the effects of World War II, the Korean War, and urbanization. The oldest age group showed that the population growth of Koreans had already been substantial at least since the end of the 19th century.

Investigation of genetic variability in commercial and invaded natural populations of red swamp crayfish(Procambarus clarkii) from South Korea (미국가재(Procambarus clarkii) 수족관 개체군 및 국내 침입 자연개체군의 유전적 변이 연구)

  • Ji Hyoun Kang;Jeong Mi Hwang;Soon-Jik Kwon;Min Jeong Baek;Sun-Jae Park;Changseob Lim;Yeon Jae Bae
    • Korean Journal of Environmental Biology
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    • v.41 no.3
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    • pp.325-334
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    • 2023
  • The invasive red swamp crayfish, Procambarus clarkii, is native to south-central United States and northeastern Mexico. Recently, it has been being spreading in the wild in South Korea. However, its primary sources, introduction routes, establishment, and expansion in South Korea remain unclear. Here, we analyzed genetic diversity and population genetic structures of its domestic natural populations during early invasion, commercial stock from local aquaria (a suspected introduction source), and original United States population using mitochondrial COI gene sequences for 267 individuals and eight microsatellite markers for 158 individuals. Natural and commercial populations of P. clarkii showed reduced genetic diversity (e.g., haplotype diversity and allelic richness). The highest genetic diversity was observed in one original source population based on both genetic markers. Despite a large number of individuals in commercial aquaria, we detected remarkably low genetic diversity and only three haplotypes among 226 individuals, suggesting an inbred population likely originating from a small founder group. Additionally, the low genetic diversity in the natural population indicates a small effective population size during early establishment of P. clarkii in South Korea. Interestingly, genetic differentiation between natural populations and the United States population was lower than that between natural populations and aquarium populations. This suggests that various genetic types from the United States likely have entered different domestic aquariums, leading to distinct natural populations through separate pathways. Results of our study will provide an insight on the level of genetic divergence and population differentiation during the initial stage of invasion of non-indigenous species into new environments.

Genetic Variation in the Natural Populations of Korean Stewartia (Stewartia koreana Nakai) Based on I-SSR Analysis (I-SSR 분석에 의한 노각나무 천연집단의 유전변이)

  • Yang Byeung-Hoon;Koo Yeong-Bon;Park Yong-Goo;Han Sang-Don
    • Korean Journal of Plant Resources
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    • v.19 no.1
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    • pp.189-195
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    • 2006
  • We investigated the genetic variation in Stewartia koreana Nakai by examining 61 I-SSR amplicons in 120 individuals distributed among six natural populations in Korea. The overall percentage of polymorphic I-SSR amplicons was 81.9% and mean number of amplicons per I-SSR primer was 12.2. Levels of genetic diversity within 6 populations were similar each other[Shannon's Index $0.358{\sim}0.467$(mean: 0.407)]. The Mt. Obong population had the highest level of genetic diversity and was most distinctive from the other populations. Most variation existed among individuals within population(88.2%). Genetic differentiation among populations(${\phi}_{ST}$) was 0.118. The UPGMA dendrogram based on the genetic distance failed in showing decisive geographic relationships.

Allozyme Diversity in Korean Populations of Calystegia soldanella and C. japonica (Convolvulaceae): Implications for Conservation

  • Chung, Myong Gi
    • Journal of Plant Biology
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    • v.38 no.2
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    • pp.173-180
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    • 1995
  • We investigated levels and distribution of genetic variation in Korean populations of Calystegia soldanella and C. japonica, clonally reproducing herbaceous perennials. Calystegia soldanella is one ofecologically important beach plants growing only on sand and beach dunes in Europe, East Asia, the Pacific Islands, and the west coast of North America. In contrast, C. japonica usually grows on small mounds of paddy fields, roadsides, and waste places with patchy distribution. Starch gel electrophoresis was conducted on leaves collected from 13 populations of C. soldanella and eight populations of C. japonica. The levels of genetic variation of the two species are very comparable; means of expected heterozygosity (Hep) were 0.100 and 0.099 for C. soldanella and C. japonica, respectively. These values were also very similar to those for species with similar life-history and ecological traits. However, the proportion of total genetic diversity partitioned among populations (GST) of C. soldanella (0.146) was considerably lower than that of C. japonica (0.383). In addition, means of Nei's genetic identity (Ⅰ) for C. soldanella and C. japonica were 0.985 and 0.900, respectively, which supports a restricted gene flow resulting from obligate clonal reproduction of C. japonica. Significant differences in allele frequency were detected among populations at eight and nine of nine polymorphic loci for C. soldanella and C. japonica (P<0.01), respecitvely. Considering the ecological importance of C. soldanella, the isolated beach populations coupled with present destruction of natural habitats of the species may result in erosion of genetic diversity in the near future. In this respect, conservation efforts should be focused on those populations that currently maintain the most genetic diversity such as those populations in the eastern and southeastern Korean Peninsula and Hamduck Beach, Cheju Island.

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Patterns of morphological variation in the Schlegel's Japanese gecko (Gekko japonicus) across populations in China, Japan, and Korea

  • Kim, Dae-In;Park, Il-Kook;Ota, Hidetoshi;Fong, Jonathan J.;Kim, Jong-Sun;Zhang, Yong-Pu;Li, Shu-Ran;Choi, Woo-Jin;Park, Daesik
    • Journal of Ecology and Environment
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    • v.43 no.4
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    • pp.332-340
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    • 2019
  • Background: Studies of morphological variation within and among populations provide an opportunity to understand local adaptation and potential patterns of gene flow. To study the evolutionary divergence patterns of Schlegel's Japanese gecko (Gekko japonicus) across its distribution, we analyzed data for 15 morphological characters of 324 individuals across 11 populations (2 in China, 4 in Japan, and 5 in Korea). Results: Among-population morphological variation was smaller than within-population variation, which was primarily explained by variation in axilla-groin length, number of infralabials, number of scansors on toe IV, and head-related variables such as head height and width. The population discrimination power was 32.4% and in cluster analysis, populations from the three countries tended to intermix in two major groups. Conclusion: Our results indicate that morphological differentiation among the studied populations is scarce, suggesting short history for some populations after their establishment, frequent migration of individuals among the populations, and/or local morphological differentiation in similar urban habitats. Nevertheless, we detected interesting phenetic patterns that may predict consistent linkage of particular populations that are independent of national borders. Additional sampling across the range and inclusion of genetic data could give further clue for the historical relationship among Chinese, Japanese, and Korean populations of G. japonicus.

Distribution, vegetation characteristics and assessment of the conservation status of a rare and endemic plant, Coreanomecon hylomeconoides Nakai (희귀·특산식물 매미꽃의 분포와 자생지 식생특성 및 보전 지위 평가)

  • Song, Sung-Won;Chung, Jae-Min;Shin, Jae-Kwon;Lee, Byung-Chun;Park, Kwang-Woo;Park, SeonJoo
    • Korean Journal of Plant Taxonomy
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    • v.42 no.2
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    • pp.116-125
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    • 2012
  • The distribution, vegetation characteristics and an assessment of the conservation status of the Korea endemic species Coreanomecon hylomeconoides Nakai were investigated to collect biological basic data to formulate a conservation strategy. According to the distribution map of C. hylomeconoides based on the literature, specimen information, and local field surveys, natural populations of C. hylomeconoides are intensively distributed in the Southern regions of the peninsula, around Gyeongsangnam-do and Jeollanan-do. C. hylomeconoides was distributed in the middle and low slope adjacent to a valley. The altitude ranged from 227 m to 744 m, with inclinations of $5-10^{\circ}$. As a result of a vegetation survey within natural populations, a total of 238 taxa were identified from 29 quadrates in 8 natural populations. The importance value of C. hylomeconoides is 25.34% based on the coverage and frequency of the herbaceous layer with in the populations. The species diversity of the occurrence of the species in 8 natural populations was 1.52, while the averages of species evenness and the dominance values were calculated to be 0.83 and 0.17, respectively. As a result of assessing the conservation status through IUCN Red List criteria, C. hylomeconoides was evaluated as Near Threatened (NT). Conservation strategies are also discussed for the sustainable conservation of C. hylomeconoides.

Genetic Diversify and Population Structure of Two Korean Pond Frog Species, Rana nigromaculata and R. plancyi (Anura, Ranidae), with a Survey of Temporal Genetic Variation in R. nigromaculata

  • Suh-Yung Yang;Jong-Bum Kim;Mi-Sook Min;Jae-Hwa Suh
    • Animal cells and systems
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    • v.3 no.3
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    • pp.275-283
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    • 1999
  • Korean R. plancyi occupies a restricted area in western South Korea and shows a relatively low level of genic variability (%P=15.2, Ho=0.052, He=0.048). In contrast, R. nigromaculata is broadly distributed in South Korea. The observed low level of variability of R. nigromaculata (%P=14.3, Ho=0.042, He=0.043) is probably due to its recent colonization. Populations of R. nigromaculata exhibited considerable genetic differentiation (F$_{sT}$=0.149) and low level of gene flow (Nm=1.427) among populations, compared to those of R. Plancyi (F$_{sTF$_{sT}$}$=0.096, Nm=2.354), which occupies a restricted area. The observed levels of gene flow among populations of R. nigromaculata (Nm=1.427) over a broad geographic range is relatively higher than other amphibian species. The high level of gene flow is probably the result of the high dispersal abilities of R. nigromaculata. A survey of temporal genic variation of R. nigromaculata showed that there was no significant change on the overall average genetic diversity from 1978 (average He=0.044) to 1997 (average He=0.040). Wright's F-statistics also indicated no significant genetic differentiation from 1978 (F$_{sT}$=0.118) to 1997 (F$_{sT}$=0.108). This suggests that the environmental change appears to have had little influence on the genetic composition of R. nigromaculata in the study areas during the past 20 years. The low level of temporal variation might be due to the result of high dispersal abilities and wide migration range of this species.

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Reproduction Strategies of Clonal Plants of Potentilla conferta in Uzbekistan and Mongol

  • Huh, Man-Kyu;Lee, Byeong-Ryong
    • Journal of Environmental Science International
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    • v.21 no.11
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    • pp.1297-1305
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    • 2012
  • Clonal plants combine sexual and clonal reproduction, which contribute differently to plant fitness. Reproductive analyses have highlighted the importance of clonal growth in shaping the spatial genetic structure in Potentilla conferta Bunge, a herbaceous rhizomatic clonal distributed in hot sand dunes. We investigated the reproduction system of P. conferta at two populations in Mongol and three natural populations in Uzbekistan. The measurements of 19 quantitative or qualitative morphological characters were taken on each of total individuals directly from their natural habitats. Some morphological characteristics between Mongolia and Uzbekistan populations showed a slight heterogeneity of variance. Especially, the length of internodes (LFI and LSI) and characteristics of root (LLR and NOR) were shown a significant difference between two countries (P<0.05). P. conferta of Uzbekistan has most ramets at short distance intervals 30~100 cm. In light conditions, P. conferta of Uzbekistan was significantly less resilience than P. conferta of Mogol. In drought conditions, although there was not shown significant difference, P. conferta in Uzbekistan was less resilience than that in Mogol. The core analysis indicates that P. conferta in Uzbekistan is the more resistant than that of Mongol and seems to do by sexual reproduction strategy during several strong environmental disadvantages such as drought events.