• 제목/요약/키워드: Genetic clusters

검색결과 287건 처리시간 0.028초

Genealogical Relationship between Pedigree and Microsatellite Information and Analysis of Genetic Structure of a Highly Inbred Japanese Black Cattle Strain

  • Sasazaki, S.;Honda, T.;Fukushima, M.;Oyama, K.;Mannen, H.;Mukai, F.;Tsuji, S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제17권10호
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    • pp.1355-1359
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    • 2004
  • Japanese Black cattle of Hyogo prefecture (Tajima strain) are famous for its ability to produce high-quality meat and have been maintained as a closed system for more than 80 years. In order to assess the usefulness of microsatellite markers in closed cattle populations, and evaluate the genetic structure of the Tajima strain, we analyzed representative dams of the Tajima strain comprised of the substrains Nakadoi and Kinosaki. Genetic variability analyses indicated low genetic diversity in the Tajima strain. In addition, a recent genetic bottleneck, which could be accounted for by the high level of inbreeding, was detected in both substrains. In phylogenetic analyses, relationship coefficients and genetic distances between individuals were calculated using pedigree and microsatellite information. Two phylogenetic trees were constructed from microsatellite and pedigree information using the UPGMA method. Both trees illustrated that most individuals were distinguished clearly on the basis of the two substrains, although in the microsatellite tree some individuals appeared in clusters of different substrains. Comparing the two phylogenetic trees revealed good consistency between the microsatellite analysis tree and the pedigree information. The correlation coefficient between genetic distances derived from microsatellite and pedigree information was 0.686 with a high significance level (p<0.001). These results indicated that microsatellite information may provide data substantially equivalent to pedigree information even in unusually inbred herds of cattle, and suggested that microsatellite markers may be useful in revealing genetic structure without accurate or complete pedigree nformation. Japanese Black cattle of Hyogo prefecture (Tajima strain) are famous for its ability to produce high-quality meat and have been maintained as a closed system for more than 80 years. In order to assess the usefulness of microsatellite markers in closed cattle populations, and evaluate the genetic structure of the Tajima strain, we analyzed representative dams of the Tajima strain comprised of the substrains Nakadoi and Kinosaki. Genetic variability analyses indicated low genetic diversity in the Tajima strain. In addition, a recent genetic bottleneck, which could be accounted for by the high level of inbreeding, was detected in both substrains. In phylogenetic analyses, relationship coefficients and genetic distances between individuals were calculated using pedigree and microsatellite information. Two phylogenetic trees were constructed from microsatellite and pedigree information using the UPGMA method. Both trees illustrated that most individuals were distinguished clearly on the basis of the two substrains, although in the microsatellite tree some individuals appeared in clusters of different substrains. Comparing the two phylogenetic trees revealed good consistency between the microsatellite analysis tree and the pedigree information. The correlation coefficient between genetic distances derived from microsatellite and pedigree information was 0.686 with a high significance level (p<0.001). These results indicated that microsatellite information may provide data substantially equivalent to pedigree information even in unusually inbred herds of cattle, and suggested that microsatellite markers may be useful in revealing genetic structure without accurate or complete pedigree information.

Multivariate Analysis of Agronomic Characteristics of Wheat (Triticum spp.) Germplasm

  • Pilmo Sung;Mesfin Haile Kebede;Seung-Bum Lee;Eunae Yoo;Gyu-Taek Cho;Nayoung Ro
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.303-303
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    • 2022
  • The purpose of this study was to evaluate agronomic characteristics and identify the useful traits to utilize the wheat genetic resources for breeding programs by understanding the phenotypic variation among germplasm through multivariate analysis. In this study, a total of 394 wheat accessions were characterized for 15 agronomic traits using the National Agrobiodiversity Center (NAC) descriptor list, of which 31 accessions from 6 species and 363 unidentified accession (Triticum spp.) available at the NAC, Rural Development Administration (RDA), Korea. Growth characteristics such as leaf width, culm length, spike length, spikelet length, solid stemmed, days to heading, days to maturity, grain-filing period, and also seed characteristics such as width, height, area, perimeter, circle, solidity, and germination percent were studied. Among the 15 agronomic characteristics, the germination percent showed the smallest variation between resources (CV = 0.4%), and the spikelet length (CV = 66.5%) showed the highest variation. A strong positive correlation was found between seed traits such as seed height and seed area (r = 0.90), seed height and seed perimeter (r = 0.87) and seed length and width (r = 0.80). Principal component analysis (PCA) was conducted and the first five principal components comprised 76.7% of the total variance. Among the first five PCs, PCI accounted for 28.5% and PC2 for 20.0%. Wheat resources (394) were classified into four clusters based on cluster analysis, consisting of 215 resources(I), 117 resources(II), 48 resources(III), and 14 resources(IV). Among the clusters, the resources belonging to Cluster III showed the lowest seed width, height, area, and perimeter characteristics compared to other clusters. The wheat resources belonging to cluster IV had small seed width and low germination percent, but took longer to form heads and mature than resources in other clusters. These results will serve as the basis for further genetic diversity studies, and important agronomic characteristics will be used for improving wheat, including developing high-yielding and resistant varieties to biotic and abiotic stresses via breeding programs.

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Genetic diversity analysis of tea (Camellia sinensis (L.) O. Kuntze) germplasm in Korea genebank

  • 현도윤;이정로;조규택;;신명재;이경준
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2019년도 춘계학술대회
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    • pp.63-63
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    • 2019
  • Tea plant (Camellia sinensis (L.) O. Kuntze) has been cultivated widely in many developing Asian, African, and South American countries, where it is the most widely consumed beverage in the world next to water. It has critical importance to understand the genetic diversity and population sturcutre for effective collection, conservation, and utilization of tea germplasm. In this study, 410 tea accessions collected from South Korea were analyzed using 21 SSR markers. Among 410 tea accessions, 85.4% (310 accessions) accessions were collected from Jeollanam-do. A total of 286 alleles were observed, and the genetic diversity and evenness were estimated to be averagely 0.79 and 0.61, respectively, across all the tested samples. Using discriminant analysis of principal components, the four clusters were detected in 410 tea accessions. Among them, cluster 1 showed higher frequency of rare alleles (less than 1%) than other clusters. Using calculation of the index of association and rbaD value, each cluster showed a clonal mode of reproduction. The result of AMOVA showed that most of the variation observed was within populations (99%) rather than among populations (1%). Our results might contribute to provide data about genetic diversity for the conservation of tea germplasm and for future breeding programs.

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Genetic Variability in the Natural Populations of Daba Ecorace of Tasar Silkworm (Antheraea mylitta Drury), as Revealed by ISSR Markers

  • Mohandas, T.P.;Vijayan, K.;Kar, P.K.;Awasthi, A.K.;Saratchandra, B.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제8권2호
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    • pp.211-215
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    • 2004
  • Genetic diversity within the natural populations of Daba ecorace of Antheraea mylitta Drury was studied using individual silkworms collected from the South Singhbhum district of Jharkhand state of India with 21 inter simple sequence repeat (ISSR) primers. A total of 148 bands were produced, of which 79% was polymorphic. The pair wise genetic distance among the individuals varied from 0.186 to 0.329. The dendrogram grouped the individuals into 3 major clusters. Nei's heterozygosity analysis revealed 0.265 ${\times}$ 0.18 variability within the population. The high genetic variability present within the natural population of Daba ecorace of A. mylitta is indicative of their adaptational strategy in nature and have much importance for in situ conservation as well as utilization in breeding programs.

Genetic diversity and population structure of endangered Neofinetia falcata (Orchidaceae) in South Korea based on microsatellite analysis

  • Han, Jeong Eun;Choi, Byoung-Hee;Kwak, Myounghai
    • Journal of Species Research
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    • 제7권4호
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    • pp.354-362
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    • 2018
  • Population genetic assessment is essential for the conservation and management of endangered and rare plants. Neofinetia falcata is endangered epiphyte orchid and protected by law in Korea. In Korea, this species is only found on islands in the South Sea of Korea (including Jeju-do) and the southern coast of the Korean Peninsula. We developed nine microsatellite makers to assess the genetic diversity and population genetic structure of three populations of N. falcata. The genetic diversity at the species level was low, which can be attributed to inbreeding or fragmentation into small, isolated populations. A recent bottleneck was detected in one population, likely due to overcollection. N. falcata exhibited moderated levels of differentiation among populations, with the three populations were divided into two clusters based on genetic structure. The genetic diversity and structure of N. falcata are affected by restricted gene flow by pollen or seeds due to isolation and geographic distance. Strategies for in situ and ex situ conservation of this species are been proposed based on the results of our study.

SMT 검사기의 경로 계획을 위한 통합적 접근 방법 (A Unified Approach to Path Planning of SMT Inspection Machines)

  • 김화중;정진회;박태형
    • 제어로봇시스템학회논문지
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    • 제10권8호
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    • pp.711-717
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    • 2004
  • We propose a path planning method to improve the productivity of SMT (surface mount technology) inspection machines with an area camera. A unified method is newly proposed to determine the FOV clusters and camera sequence simultaneously. The proposed method is implemented by a hybrid genetic algorithm to increase the convergence speed. Comparative simulation results are then presented to verify the usefulness of the proposed algorithm.

Genetic Variations between Hairtail (Trichiurus lepturus) Populations from Korea and China

  • Yoon, Jong-Man
    • 한국발생생물학회지:발생과생식
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    • 제17권4호
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    • pp.363-367
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    • 2013
  • PCR analysis generated on the genetic data showed that the geographic hairtail (Trichiurus lepturus) population from Korea in the Yellow Sea was more or less separated from geographic hairtail population from China in the South Sea. The average bandsharing value ($mean{\pm}SD$) within hairtail population from Korea showed $0.859{\pm}0.031$, whereas $0.752{\pm}0.039$ within population from China. Also, bandsharing values between two hairtail populations ranged from 0.470 to 0.611, with an average of $0.542{\pm}0.059$. As compared separately, the bandsharing values of individuals within hairtail population from Korea were comparatively higher than those of individuals within population from China. The hierarchical dendrogram resulted from reliable oligonucleotides primers, indicating two genetic clusters composed of cluster 1 (KOREANHAIR1~KOREANHAIR11) and cluster 2 (CHINESEHAI12~CHINESEHAI22). The genetic distances between two geographic populations ranged from 0.038 to 0.476. Individual No. 11 within hairtail population from Korea was genetically closely related with No. 10 (genetic distance=0.038). The longest genetic distance (0.476) displaying significant molecular difference was also between individual No. 01 within hairtail population from Korea and No. 22 from Chinese. In the present study, PCR analysis has revealed significant genetic distances between two hairtail population pairs (P<0.05).

Genetic Distances in Two Gracilaria Species (Gracilariaceae, Rhodophyta) Identified by PCR Technique

  • Kim, Young Sik;Yoon, Jong-Man
    • 한국발생생물학회지:발생과생식
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    • 제22권4호
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    • pp.393-402
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    • 2018
  • Genomic DNA was isolated from the Gracilaria vermiculophylla (GRV) and G. chorda (GRC) from Jangheung located in the southern sea of the Korean Peninsula, respectively and we performed clustering analyses, DNA polymorphisms and the genetic differences. The seven selected primers OPC-01, OPA-04, OPA-05, OPD-07, OPD-08, OPB-10, and OPD-16 generated average bandsharing (BS) value, the genetic distance and dendrogram. The size of DNA bands varies from 90 bp to 2,400 bp. The average BS value was $0.859{\pm}0.004$ within GRV and $0.916{\pm}0.006$ within GRC. The average BS value between two Gracilaria species was $0.340{\pm}0.003$, ranged from 0.250 to 0.415. The dendrogram obtained by the seven primers, indicates two genetic clusters. The genetic distance between two Gracilaria species ranged from 0.059 to 0.513. The individual VERMICULOPHYLLA no. 07 of GRV was genetically closely related to VERMICULOPHYLLA no. 06 of GRV (genetic distance=0.059). Especially, two entities between the individual VERMICULOPHYLLA no. 10 of GRV and CHORDA no. 22 of GRC showed the longest genetic distance (0.513) in comparison with other individuals used. Accordingly, as mentioned above, PCR analysis showed that the GRV was a little more genetically diverse than the GRC species. We convinced that this DNA analysis revealed a significant genetic distance between two Gracilaria species pairs (p<0.01).

Genetic Diversity of Ascaris in China Assessed Using Simple Sequence Repeat Markers

  • Zhou, Chunhua;Jian, Shaoqing;Peng, Weidong;Li, Min
    • Parasites, Hosts and Diseases
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    • 제56권2호
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    • pp.175-181
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    • 2018
  • The giant roundworm Ascaris infects pigs and people worldwide and causes serious diseases. The taxonomic relationship between Ascaris suum and Ascaris lumbricoides is still unclear. The purpose of the present study was to investigate the genetic diversity and population genetic structure of 258 Ascaris specimens from humans and pigs from 6 sympatric regions in Ascaris-endemic regions of China using existing simple sequence repeat data. The microsatellite markers showed a high level of allelic richness and genetic diversity in the samples. Each of the populations demonstrated excess homozygosity (Ho0). According to a genetic differentiation index (Fst=0.0593), there was a high-level of gene flow in the Ascaris populations. A hierarchical analysis on molecular variance revealed remarkably high levels of variation within the populations. Moreover, a population structure analysis indicated that Ascaris populations fell into 3 main genetic clusters, interpreted as A. suum, A. lumbricoides, and a hybrid of the species. We speculated that humans can be infected with A. lumbricoides, A. suum, and the hybrid, but pigs were mainly infected with A. suum. This study provided new information on the genetic diversity and population structure of Ascaris from human and pigs in China, which can be used for designing Ascaris control strategies. It can also be beneficial to understand the introgression of host affiliation.

Genetic Distances between Two Cultured Penaeid Shrimp (Penaeus chinensis) Populations Determined by PCR Analysis

  • Yoon, Jong-Man
    • 한국발생생물학회지:발생과생식
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    • 제23권2호
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    • pp.193-198
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    • 2019
  • Genomic DNA samples were obtained from cultured penaeid shrimp (Penaeus chinensis) individuals such as fresh shrimp population (FSP) and deceased shrimp population (DSP) from Shinan regions in the Korean peninsula. In this study, 233 loci were identified in the FSP shrimp population and 162 in the DSP shrimp population: 33 specific loci (14.2%) in the FSP shrimp population and 42 (25.9%) in the DSP population. A total of 66 (an average of 9.4 per primer) were observed in DSP shrimp population, whereas 55 unique loci to each population (an average of 7.9 per primer) in the FSP shrimp population. The Hierarchical dendrogram extended by the seven oligonucleotides primers indicates three genetic clusters: cluster 1 (FRESH 01, 02, and DECEASED 12, 13, 15, 16, 17, 19, 20, 22) and cluster 2 (FRESH 03, 04, 05, 06, 07, 08, 09, 10, 11, and DECEASED 14, 18, 21). Among the twenty-two shrimp, the shortest genetic distance that exposed significant molecular differences was between individuals 20 and 16 from the DSP shrimp population (genetic distance=0.071), while the longest genetic distance among the twenty-two individuals that established significant molecular differences was between individuals FRESH no. 02 and FRESH no. 04 (genetic distance=0.477). In due course, PCR analysis has revealed the significant genetic distance among two penaeid shrimp populations.