• 제목/요약/키워드: structure and diversity

검색결과 1,779건 처리시간 0.029초

Assessing Biodiversity of Benthic Macroinvertebrates and Influences of Several Environmental Factors on the Community Structure in Upo Wetland by Long-term Ecological Monitoring

  • Kim, Hyoung-Gon;Lee, Dong-Jun;Yoon, Chun-Sik;Cheong, Seon-Woo
    • 한국환경과학회지
    • /
    • 제25권4호
    • /
    • pp.459-472
    • /
    • 2016
  • We assessed the distribution of benthic macroinvertebrate at four surveying sites in Upo Wetland, a Ramsar site and the largest wetland in Korea, from February 2006 to November 2013. A long-term ecological monitoring was done monthly by using quantitative sampling method with dip net for analyzing the community change and correlation between the biodiversity and the environmental factors because environmental factors have a decisive effect on the community structure of the benthic macroinvertebrates. Total samples from the Upo Wetland area were classified into 3 phyla, 6 classes, 17 orders, 68 families, 176 species, and 25,720 individuals. Among the 176 species, 62 of the species had not been previously reported in this area. Asellus sp., Diplonychus esakii, and Gyraulus chinensis were the most common species in Upo Wetland. The change patterns of annual species diversity and species richness were calculated by using the average number of monthly occurring species and individuals. Diversity index increased from March to May and decreased after that showing lower diversity indices in July and August. It increased again in September and in October. Richness index showed similar tendency and fell around February and July, followed by a rising tendency around May and October. Correlation and regression analyses were performed with the change of biodiversity and each environmental factor. We found that water temperature have very significant positive correlation with species diversity in spring, and have significant indices in autumn and winter. On the other hand, precipitation showed a significantly negative correlation value in summer and autumn suggesting it has an effect on the community structure of benthic macroinvertebrates.

Genetic variation and structure of Juniperus chinensis L. (Cupressaceae) in Korea

  • Kim, Eun-Hye;Shin, Jae-Kwon;Jeong, Keum-Seon;Lee, Chang-Seok;Chung, Jae-Min
    • Journal of Ecology and Environment
    • /
    • 제42권3호
    • /
    • pp.111-119
    • /
    • 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.

Genetic diversity and population structure of mongolian wheat based on SSR markers

  • Ya, Narantsetseg;Raveendar, Sebastin;Bayarsukh, N;Ya, Myagmarsuren;Lee, Jung-Ro;Lee, Kyung-Jun;Shin, Myoung-Jae;Cho, Yang-Hee;Ma, Kyung-Ho;Lee, Gi-An
    • 한국작물학회:학술대회논문집
    • /
    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
    • /
    • pp.82-82
    • /
    • 2017
  • The production of spring wheat, the major crop in Mongolia, is accounting for 98% of the cultivated area. Collection, conservation and utilization of wheat germplasm resources play an important role in wheat breeding and production in Mongolia. Understanding genetic variability in the existing genebank accessions is important for collection and conservation of wheat germplasms. To determine the genetic diversity and population structure among a representative collection of Mongolian local wheat cultivars and lines, 200 wheat accessions were analyzed with 15 SSR markers distributed throughout the wheat genome. A total of 85 alleles were detected, with 3 to 5 alleles per locus and a mean genetic diversity value of 5.66. The average genetic diversity index was 0.68, with values ranging from 0.37 to 0.80. The 200 Mongolian wheat accessions were divided into two subgroups based on STRUCTURE, un-rooted NJ cluster and principal coordinate analyses. The results from this study will provide important information for future wheat germplasm conservation and improvement programs with Mongolian genebank.

  • PDF

Population genetic structure and genetic variability of the marbled sole Pleuronectes yokohamae on the coast of Gyeongsangnam-do, Korea

  • Lee, So-Jeong;Lee, So-Gwang;Gwak, Woo-Seok
    • Animal cells and systems
    • /
    • 제16권6호
    • /
    • pp.498-505
    • /
    • 2012
  • This study uses the mitochondrial DNA control region to identify the genetic diversity and population structure of the marbled soles (Pleuronectes yokohamae) that inhabit Jinhae Bay and Yokji Island in the nearby sea and the adjacent waters of Namhae, Hansan Island, and Jaran Bay. Direct sequencing of the PCR products revealed 379 bp sequences with 83 variable nucleotide sites, defining a total of 91 haplotypes. The haplotype diversity was high, ranging from $0.917{\pm}0.031$ to $0.983{\pm}0.008$, and nucleotide diversity ranged from $0.015{\pm}0.008$ to $0.024{\pm}0.012$. In addition, 48 haplotypes (52.7%) were unique. Pairwise $F_{ST}$ values were very low, with the maximum value occurring between PYH (Hansan Island) and PJI (Jinhae Bay) ($F_{ST}$ = 0.011). Therefore, no significant genetic differentiation was evident between any pair of sampling localities.

Genetic Diversity and Population Structure of Glehnia littoralis (Umbelliferae) in Korea

  • Huh Man Kyu;Choi Joo Soo;Huh Hong Wook;Choi Yung Hyun;Choi Byung Tae
    • 동의생리병리학회지
    • /
    • 제17권6호
    • /
    • pp.1519-1523
    • /
    • 2003
  • Glehnia littoralis Fr. Schmidt (Umbelliferae) is a short-lived herbaceous species that are mostly distributed throughout East Asia. Although G. littoralis has been regarded as ecologically important one, there is no report on population structure in Korea. Starch gel electrophoresis was used to investigate the allozyme variation and genetic structure of Korean populations of this species. A high level of genetic variation was found in G. littoral is populations. Nine enzymes revealed 18 loci, of which 12 were polymorphic (66.7%). Genetic diversity at the species and population levels were 0.159 and 0.129, respectively. The sexual and asexual reproduction, high fecundity, and colonization process are proposed as possible factors contributing to genetic diversity. An indirect estimate of the number of migrants per generation (Nm = 1.45) indicated that gene flow was not extensive among Korean populations of this species. It is suggested that the ability of vegetation and artificial selection may have played roles in shaping the population structure of this species. we recommend that a desirable conservation population should be included at least 30 plants per population and especially those with high variation.

화전 후 묵밭의 식생 천이에 따른 종다양성 및 식생 구조의 발달 (Changes of Species Diversity and Development of Vegetation Structure during Abandoned Field Succession after Shifting Cultivation in Korea)

  • 이규송
    • Journal of Ecology and Environment
    • /
    • 제29권3호
    • /
    • pp.227-235
    • /
    • 2006
  • 강원도 평창군 일대에서 화전 후 묵밭의 식생 천이에 따른 식생 구조의 발달 과정과 종다양성의 변화를 조사하였다. 방치 후 경과 년 수에 따라 최상층부의 키는 초기에 빠르게 증가하고 후기에 안정화하는 경향을 나타내었다. 10, 20, 50 및 80 년차 묵밭에서 최상층부 식생의 키는 각각 4, 8, 18 및 18 m이었다. 교목층, 아교목층, 관목층 및 초본층의 4층 구조를 갖춘 완전한 형태의 숲으로 발달하기까지는 방치 후 약 35년이 경과해야 하는 것으로 추정되었다. 방치 후 경과 년 수에 따라 식생치 Ivc는 로그 함수적으로 그리고 식생치 Hcl은 직선적으로 증가하는 경향이 있었다. 묵밭의 식생천이에서 종다양성은 천이 중기인 $10{\sim}20$년차에서 최고로 증가한 다음 이후 점차 감소하는 경향을 나타내었다. 본 조사지에서 종다양성은 균등도보다 종풍부도와 매우 밀접한 상관을 나타내었다. 대부분의 목본은 개망초-쑥 단계인 $2{\sim}6$년차에 정착이 이루어져 시간 경과에 따라 이들의 우점도가 변화함으로써 Egler (1954)의 초기 종조성 모델을 따르는 것으로 확인되었다.

Genetic Diversity and Population Structure of Peanut (Arachis hypogaea L.) Accessions from Five Different Origins

  • Zou, Kunyan;Kim, Ki-Seung;Lee, Daewoong;Jun, Tae-Hwan
    • 한국작물학회지
    • /
    • 제65권4호
    • /
    • pp.447-456
    • /
    • 2020
  • Peanut is an allotetraploid derived from a single recent polyploidization. Polyploidization has been reported to have caused significant loss in genetic diversity during the domestication of cultivated peanuts. Single nucleotide polymorphism (SNP)-based markers such as cleaved amplified polymorphic sequences (CAPS) derived from next-generation sequencing (NGS) have been developed and widely applied for breeding and genetic research in peanuts. This study aimed to identify the genetic diversity and population structure using 30 CAPS markers and 96 peanut accessions from five different origins. High genetic dissimilarities were detected between the accessions from Korea and those from the other three South American origins generally regarded as the origin of peanuts, while the accessions from Brazil and Argentina presented the lowest genetic dissimilarity. Based on the results of the present study, accessions from Korea have unique genetic variation compared to those from other countries, while accessions from the other four origins are closely related. Our study identified the genetic differentiation in 96 peanut accessions from five different origins, and this study also showed the successful application of SNP information derived from re-sequencing based on NGS technology.

Genetic Variation and Population Structure of Alder (Alnus hirsuta : Betulaceae) in Korea

  • Park, Joo-Soo;Huh, Man-Kyu
    • Journal of Life Science
    • /
    • 제10권1호
    • /
    • pp.14-19
    • /
    • 2000
  • Variation at 25 allozyme loci in Korean wateralder (Alnus hirsuta Rupr.) from nine distinct populations was measured to estimate the amount and pattern of genetic diversity and population structure. The mean genetic diversity within population was 0.166. Korean alder populations have slightly high levels of genetic diversity compared to those present in associated temperature-zone species and two Canadian alder species. Among population s genetic differentiation accounted for an significant 9% of the total variation. High gene flow(Nm=2.63) was observed. Analysis of fixation indices, calculated for all polymorphic loci in each population, showed a substantial deficiency of heterozygotes relative to Hardy-Weinberg expectations. The mean GST value A. hirsuta in Korea (GST = 0.087) is similar to those of A. rogosa in Canada (GST = 0.052). These low values of GST in two countries. reflecting little spatial genetic differentiation, may indicate extensive gene flow (via pollen and/or seeds) and/or recent colonization. These factors reduce the effect of geographic isolation of breeding and the chance for genetic divergence. A pattern of increasing is observed with increasing rainfall per year. Regression analysis indicates that 54% (F = 4.67) of the variability observed can be explained by this relationship.

  • PDF

Genetic Diversity and Spatial Structure of Symplocarpus renifolius on Mt. Cheonma, Korea

  • Jeong, Ji-Hee;Park, Yu-Jin;Kim, Zin-Suh
    • 한국자원식물학회지
    • /
    • 제20권6호
    • /
    • pp.530-539
    • /
    • 2007
  • Genetic variation and structure of 9 subpopulations of Symplocarpus renifolius Schott ex Tzvelev on Mt. Cheonma, in Korea, were determined via starch-gel electrophoresis. The genetic diversity at 10 loci for 8 isozymes ($P_{99}=66%,\;A=2.26,\;H_o=0.212,\;H_e=0.230$) was found to be considerably higher than that seen in other long-lived perennial plants. On the whole, the genotype frequencies were in accordance with Hardy-Weinberg expectations. Approximately 5%($\theta=0.049$) of the total variability was among subpopulations. The high levels of observed genetic diversity in S. renifolius were attributed to a universal outcrossing system and other specific factors like differences in age classes and widely scattered individuals around the main distribution. Heterozygosity was highest at a mid-range of elevation($450m{\sim}600m$). The lowest heterozygosity at lower elevation was attributed to the possible origin of seeds transported by water from upstream regions during the monsoon season. Spatial structure in a subpopulation evidenced a strong autocorrelation between closer individuals within $3{\sim}4m$ of distance. This was assumed to be attributable to the restricted seed dispersal characteristics of S. renifolius. In accordance with the findings generated in this study, some implications regarding the conservation of S. renifolius at the Mt. Cheonma were also presented.

Population genetic structure based on mitochondrial DNA analysis of Ikonnikov's whiskered bat (Myotis ikonnikovi-Chiroptera: Vespertilionidae) from Korea

  • Park, Soyeon;Noh, Pureum;Choi, Yu-Seong;Joo, Sungbae;Jeong, Gilsang;Kim, Sun-Sook
    • Journal of Ecology and Environment
    • /
    • 제43권4호
    • /
    • pp.454-461
    • /
    • 2019
  • Background: Ikonnikov's whiskered bat (Myotis ikonnikovi) is found throughout the Korean Peninsula, as well as in Kazakhstan, Russia, Mongolia, China, and Japan. It is small-sized and primarily inhabits old-growth forests. The decrease and fragmentation of habitats due to increased human activity may influence the genetic structure of bat populations. This study was designed to elucidate the population genetic structure of M. ikonnikovi using mitochondrial genes (cytochrome oxidase I and cytochrome b). Results: The results showed that M. ikonnikovi populations from Korea have high genetic diversity. Although genetic differentiation was not detected for the COI gene, strong genetic differentiation of the Cytb gene between Mt. Jeombong and Mt. Jiri populations was observed. Moreover, the results indicated that the gene flow of the maternal lineage may be limited. Conclusions: This study is the first to identify the genetic population structure of M. ikonnikovi. We suggest that conservation of local populations is important for sustaining the genetic diversity of the bat, and comprehensive studies on factors causing habitat fragmentation are required.