• Journal of Forest and Environmental Science
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• 제24권1호
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• pp.27-34
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• 2008

Level and distribution of genetic diversity in seven populations of Albizia lucida Benth. in eastern region of the Indian sub-continent were estimated using ISSR markers. Relatively higher level of genetic diversity within populations was observed in seven populations of A. lucida (mean of 0.38). From the result of AMOVA, majority of genetic diversity was allocated within populations (96.2%) resulting in a moderate degree of population differentiation. The observed distribution pattern of I-SSR variant among the populations was coincided with the typical pattern of long-lived woody tree species. Genetic relationships among the populations, reconstructed by UPGMA method, revealed two genetic groups. The population of Anugul and Bargarh turned out to be the most closely related despite a distance location between them. These formations will be of great value in the development of conservation plans for species exhibiting high levels of genetic differentiation due to fragmentation, such as indication of conservation unit size, which populations should be chosen as priority in conservation plans and which samples should be introduced in areas with a low number of individuals of A. lucida.

• Journal of Ecology and Environment
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• 제42권3호
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• pp.111-119
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• 2018

Background: Juniperus chinensis L. populations are distributed locally on several areas including coastal cliffs which are difficult to access in the central eastern Korea. Wild populations inhabit relatively barren environments such as rocky areas and cliffs, which are very sensitive to even minor environmental disturbances including artificial interventions and natural disturbances, and thus demonstrate great fluctuations in the population size and density. This study aims to analyze the genetic diversity, differentiation, and genetic structure of each population in order to provide useful data required to establish a substantial conservation strategy of J. chinensis. Results: The genetic diversity of J. chinensis at the population level (P = 78.7%, h = 0.282, S.I. = 0.420) was somewhat higher compared with those measured in the same genus, Juniperus. The genetic differentiation degree among nine populations established naturally in central eastern Korea was 11.50% and that among sub-populations within the same area was 5.52%. On the other hand, genetic variation of individuals within the populations was 82.93%. But frequency of the main allele was different among loci. In particular, fixation of allele frequency and occurrence of rare allele in the highly isolated population suggest a likelihood that genetic drift would occur in populations of this plant. As the result of analysis on the genetic structure of nine populations, nearby populations and isolated populations tended to form separate clusters from each other as the hypothetical number of clusters (K) increase. Conclusions: This result implies that if the population size of J. chinensis is reduced due to environmental change and artificial and/or natural disturbances in the future, it could affect negatively on the genetic diversity of the plant species. In order to maintain and conserve genetic diversity of J. chinensis, ecological network, which can help genetic exchange among the local populations, should be prepared, and conservation strategies in situ as well as ex situ are also required with continuous monitoring.

• Asian-Australasian Journal of Animal Sciences
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• 제22권1호
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• pp.1-6
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• 2009

Genetic variability is an important component in the ability of populations to adapt in the face of environmental change. Severe human impacts reduced Muzzafarnagri sheep of India from 500,000 in 1972 to 10,989 in 1973-74. Here we report for the first time the effect of this population decline on levels of genetic variability at 13 FAO recommended ovine microsatellite loci and contrast levels of variability to that in a breed from the same geographical region, which differed in numbers, by an order of magnitude (Marwari sheep). Of the 13 loci, 100% were polymorphic in both breeds. A high degree of genetic variation was observed within populations in terms of both allele diversity (number of alleles per locus, >4) and gene diversity (expected heterozygosity, >0.5), which implied that there is still a substantial amount of genetic diversity at the nuclear loci in a declining population. Nevertheless, overall low number of alleles per locus and relatively less abundance of low frequency alleles in Muzzafarnagri sheep suggested that genetic variability has been comparatively reduced in this population. Bottleneck analysis indicated that a genetic bottleneck did not occur during the most recent decline. In addition, we found that the differentiation among populations was moderate ($F_{ST}$= 11.8%). This study on assessment of genetic effects of the population declines in ovines is a step towards identification of genetically impoverished or healthy populations, which could prove to be a useful tool to facilitate conservation planning in this important species of small ruminants.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.453-457
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• 2005

The genetic variations in three major river populations viz. the Halda, the Jamuna and the Padma of the Indian major carp, Catla catla were analyzed by Random Amplified Polymorphic DNA (RAPD) markers. Four decamer primers were used for amplifying DNA of 10 individuals from each population. The proportion of polymorphic loci and the gene diversity estimates were 59.4 and 0.20 for the Halda, 37.5 and 0.14 for the Jamuna and 46.9 and 0.16 for the Padma populations respectively indicating the existence of a relatively high level of genetic variation in the Halda river population. The inter-population similarity indices, gene flow and genetic distance values indicated that the Jamuna-Padma population pair of catla was genetically closer than the Halda-Jamuna and the Halda-Padma population pairs in compliance with the geographical distances among them. The coefficient of gene differentiation ($G_{ST}$=0.13) reflects some degree of genetic differentiation among three populations of catla studied. The data suggest that the RAPD technique could be used to discriminate different river populations of catla.

• Animal Bioscience
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• 제37권7호
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• pp.1168-1176
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• 2024

Objective: As a charismatic species, cashmere goats have rich genetic resources. In the Inner Mongolia Autonomous Region, there are three cashmere goat varieties named and approved by the state. These goats are renowned for their high cashmere production and superior cashmere quality. Therefore, it is vitally important to protect their genetic resources as they will serve as breeding material for developing new varieties in the future. Methods: Three breeds including Inner Mongolia cashmere goats (IMCG), Hanshan White cashmere goats (HS), and Ujimqin white cashmere goats (WZMQ) were studied. IMCG were of three types: Aerbas (AEBS), Erlangshan (ELS), and Alashan (ALS). Nine DNA samples were collected for each population, and they were genomically re-sequenced to obtain high-depth data. The genetic diversity parameters of each population were estimated to determine selection intensity. Principal component analysis, phylogenetic tree construction and genetic differentiation parameter estimation were performed to determine genetic relationships among populations. Results: Samples from the 45 individuals from the five goat populations were sequenced, and 30,601,671 raw single nucleotide polymorphisms (SNPs) obtained. Then, variant calling was conducted using the reference genome, and 17,214,526 SNPs were retained after quality control. Individual sequencing depth of individuals ranged from 21.13× to 46.18×, with an average of 28.5×. In the AEBS, locus polymorphism (79.28) and expected heterozygosity (0.2554) proportions were the lowest, and the homologous consistency ratio (0.1021) and average inbreeding coefficient (0.1348) were the highest, indicating that this population had strong selection intensity. Conversely, ALS and WZMQ selection intensity was relatively low. Genetic distance between HS and the other four populations was relatively high, and genetic exchange existed among the other four populations. Conclusion: The Inner Mongolia cashmere goat (AEBS type) population has a relatively high selection intensity and a low genetic diversity. The IMCG (ALS type) and WZMQ populations had relatively low selection intensity and high genetic diversity. The genetic distance between HS and the other four populations was relatively high, with a moderate degree of differentiation. Overall, these genetic variations provide a solid foundation for resource identification of Inner Mongolia Autonomous Region cashmere goats in the future.

• The Plant Pathology Journal
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• 제30권1호
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• pp.10-24
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• 2014

Genetic diversity and differentiation of 50 Colletotrichum spp. isolates from legume crops studied through multigene loci, RAPD and ISSR analysis. DNA sequence comparisons by six genes (ITS, ACT, Tub2, CHS-1, GAPDH, and HIS3) verified species identity of C. truncatum, C. dematium and C. gloeosporiodes and identity C. capsici as a synonym of C. truncatum. Based on the matrix distance analysis of multigene sequences, the Colletotrichum species showed diverse degrees of intera and interspecific divergence (0.0 to 1.4%) and (15.5-19.9), respectively. A multilocus molecular phylogenetic analysis clustered Colletotrichum spp. isolates into 3 well-defined clades, representing three distinct species; C. truncatum, C. dematium and C. gloeosporioides. The ISSR and RAPD and cluster analysis exhibited a high degree of variability among different isolates and permitted the grouping of isolates of Colletotrichum spp. into three distinct clusters. Distinct populations of Colletotrichum spp. isolates were genetically in accordance with host specificity and inconsistent with geographical origins. The large population of C. truncatum showed greater amounts of genetic diversity than smaller populations of C. dematium and C. gloeosporioides species. Results of ISSR and RAPD markers were congruent, but the effective maker ratio and the number of private alleles were greater in ISSR markers.

• Fisheries and Aquatic Sciences
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• 제25권12호
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• pp.601-618
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• 2022

The genus Semisulcospira is an economically and ecologically valuable freshwater resource. Among the species, Semisulcospira coreana, Semisulcospira forticosta and Semisulcospira tegulata are endemic to the Korean peninsula and Semisulcospira gottschei is widespread in Asia. Therefore, maintenance and conservation of wild populations of these snails are important. We investigated the genetic diversity and population structure of Semisulcospira based on the mitochondrial cytochrome c oxidase subunit I (COI), NADH dehydrogenase subunit 4 (ND4), and combined mitochondrial DNA (COI + ND4) sequences. All four species and various genetic makers showed a high level of haplotype diversity and a low level of nucleotide diversity. In addition, Fu's Fs and Tajima's D neutrality tests were performed to assess the variation in size among populations. Neutrality tests of the four species yielded negative Fu's Fs and Tajima's D values, except for populations with one haplotype. The minimum spanning network indicated a common haplotype for populations of S. coreana, S. tegulata and S. gottschei, whereas S. forticosta had a rare haplotype. Also, genetic differences and gene flows between populations were assessed by analysis of molecular variance and using the pairwise fixation index. Our findings provided insight into the degree of preservation of the species' genetic diversity and could be utilized to enhance the management of endemic species.

• 한국환경생태학회지
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• 제25권4호
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• pp.470-478
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• 2011

본 연구는 멸종위기식물인 단양쑥부쟁이(Aster altaicus var. uchiyamae)의 개체군을 대상으로 유전다양성을 유지하는데 필요한 최소개체수를 산정하기 위하여 수행되었다. 단양쑥부쟁이가 분포하고 있는 네 지역에서 각각 유전다양성 및 유전적 분화도를 분석하였다. AFLP(amplified fragment length polymorphism) 마커를 이용한 유전적 변이의 분석결과, 총 4개의 프라이머 조합에 대해서 936개의 밴드가 확인되었으며, 그 중 934개의 밴드(99.8%)가 다형성을 보여주었다. 단양쑥부쟁이 개체군 내에서 유전다양성(PPB = 45.3%, h = 0.104, I = 0.168, hs = 0.108)은 높은 수준으로 나타났으며, 개체군 간 유전적 분화도($G_{ST}$ = 0.075, ${\theta}^B$ = 0.079)는 낮은 수준이었다. AMOVA(Analysis of molecular variance)분석 결과에서도 전체 유전적 변이 중 91%가 개체군 내에서 보이는 반면, 9%는 개체군 간 변이에 기인한 것으로 나타났다. 단양쑥부쟁이 개체군에서 보이는 유전적 특성은 개체군 간의 빈번한 유전자 이동에 기인한 것으로 사료된다. 최대화 전략법에 의하여 경기도 여주일대의 3개 개체군을 대상으로(굴암, 도리섬, 삼합) 개체군 내 최소개체수를 산정한 결과 도리섬개체군에서는 17개체, 삼합개체군에서는 16개체, 굴암개체군에서는 11개체로 파악되었다. 단양쑥부쟁이 개체군의 최소개체수에 대한 정보는 효율적인 현지 외 보전을 위한 가이드라인을 제시해 줄 수 있다.

• Animal cells and systems
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• 제5권4호
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• pp.309-312
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• 2001

Allozyme studies have been widely used to estimate genetic variation and to describe genetic structure in natural populations. In many cases, the genetic diversity of recently established populations is generally lower than that of central populations. In addition, the genetic composition of an invasive species is influenced by its History of introduction as well as its ecological characters. Ageratina altissima (L.) R. King & H. Robinson (white snakeroot) is a perennial herb native to the eastern United States and Canada, and is currently receiving much attention for its rapid invasion of the Korean forests. Starch gel electrophoresis was used to assess the genetic variability at 11 putative loci in seven introduced populations of A. altissima in Seoul. Populations of A. altissima maintained lower levels of allozyme diversity (expected heterozygosity = 0.063) than those reported for other taxa with similar ecological traits. The degree of differentiation observed among A. altissima populations was considerably low. It is suggested that the populations were recently established from only a few founders via dispersal by human activities, resulting in the loss of genetic variation.

• 한국산림과학회지
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• 제89권2호
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• pp.167-172
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• 2000

국내 5개 지역에서 채집한 비자나무(Torreya nucifera Siev. et Zucc.) 95개체를 대상으로 I-SSR 표지자를 분석하였다. 총 62개의 I-SSR 증폭산물(增幅産物)이 관찰되었으며, 그 중 7개의 증폭산물(增幅産物)은 분석된 95개 개체에서 단형성(單形性)이었다. 관찰된 전체 I-SSR 증폭산물(增幅産物)을 통합(統合)하여 분석한 결과 개체목에 대한 DNA지방판별(指放判別)이 가능하였다. 대부분의 유전다양성(遺傳多樣性)이 임분(林分)내의 개체목 간에 존재하는 것으로 나타났고(90.65%), 전체 5개 임분(林分)에서 유사한 수준의 유전다양성(遺傳多樣性)을 보였다. 집단간의 유전적(遺傳的) 분화(分化)정도는 심하지 않았다(${\phi}_{ST}=9.35%$). UPGMA법에 의한 유집분석(類集分析) 결과 각 집단의 유전적(遺傳的) 유연관계(類緣關係)는 임분(林分)의 지리적(地理的) 분포양상(分布樣相)과 일치(一致)하지 않았으며, 각 교점(交點)의 형성(形成)에 있어서 통계적 유의성이 없었고 따라서 전체 집단들이 유전적(遺傳的)으로 크게 분화(分化)되지 않았음을 알 수 있었다.