• 제목/요약/키워드: Research Diversity

검색결과 4,140건 처리시간 0.057초

Analysis of Composition and Diversity of Natural Regeneration of Woody Species in Jebel El Gerrie Dry Land Forest East of Blue Nile State, Sudan

  • Abuelbashar, Ahmed Ibrahim;Ahmed, Dafa-Alla Mohamed Dafa-Alla;Siddig, Ahmed Ali Hassabelkreem;Yagoub, Yousif Elnour;Gibreel, Haithum Hashim
    • Journal of Forest and Environmental Science
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    • 제38권2호
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    • pp.90-101
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    • 2022
  • The study aims to assess composition, diversity and population indices of natural regeneration of woody species in Jebel El Gerrie forest reserve, Blue Nile State, Sudan. We conducted field work between December 2018 and January 2019. We used random sampling to collect vegetation data in the forest where we made a total of 90 circular sample plots (radius 17.84 m) and distributed them proportionally to the area of each of the four density-based vegetation classes of the forest i.e. high density (C1), medium density (C2), low density (C3) and crop land (C4). In each sample plot we identified all regenerating tree species and counted their regeneration frequencies. We calculated ecological metrics of regeneration frequency, density, abundance, richness, evenness, diversity and importance value index (IVI) and drew abundance rank curve. Results revealed that out of fifteen mature tree species present, natural regeneration of 8 species, which belong to 6 families, was observed. The relatively most frequently naturally regenerating and abundant species were Anogeissus leiocarpa and Combretum hartmannianum. Richness, evenness and diversity of regenerating species were 1.33, 0.82 and 1.7, respectively. One-way ANOVA (α=0.05) of mean regeneration densities disclosed that there were significant differences (F3,86=16.77, p=0.000) between C2 & C3 (p=0.000) and C2 & C4 (p=0.000). While regeneration of seven tree species were absent, two, two and four species were of good, poor and fair regeneration status, respectively. A comparison of mean density of natural regeneration with that of parent trees reflects a poor regeneration status of the forest. The study provides empirical results on the regeneration status of species and signifies the need for management interventions for species conservation and restoration, maintenance of biodiversity and sustainable production.

Diversity of the Lichenized Fungi in King George Island, Antarctica, Revealed by Phylogenetic Analysis of Partial Large Subunit rDNA Sequences

  • Lee, Jin-Sung;Lee, Hong-Kum;Hur, Jae-Seoun;Andreev, Mikhail;Hong, Soon-Gyu
    • Journal of Microbiology and Biotechnology
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    • 제18권6호
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    • pp.1016-1023
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    • 2008
  • Lichens are predominant and important components of flora in the terrestrial ecosystem of Antarctica. However, relatively few researches on the phylogenetic position of Antarctic lichen-forming fungi have been accomplished. In this study, partial sequences of nuclear large subunit rDNAs from 50 Antarctic specimens were obtained and the phylogeny was reconstructed. Antarctic lichen species were distributed in 4 orders, including the monophyletic order Agyrales, paraphyletic orders Pertusariales and Teloschistales, and polyphyletic order Lecanorales. Species diversity was highest in the order Lecanorales, followed by Teloschistales and Pertusariales. Based on the phylogeny and sequence similarity analyses, it is proposed that the taxonomy of Stereocaulon alpinum, Physcia caesia, Usnea aurantiacoatra, and Cladonia species should be revised by careful examination of their phenotypic and molecular characteristics. Six species known to be endemic to Antarctica, Catillaria corymbosa, Himantormia lugubris, Leptogium puberulum, Pertusaria pertusa, Rhizoplaca aspidophora, and Umbilicaria antarctica, formed unique lineages, implying independent origins in the Antarctic area.

Microbial Diversity in Swamp

  • Hong Soon Gyu;Lee Kang Hyun;Bae Kyung Sook
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2002년도 추계학술대회
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    • pp.90-93
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    • 2002
  • The revolution in molecular biology has given us greatly increased ability to obtain and to modify biological resources and to use them for the benefit of all humankind. The sequencing and the associated analysis of gene functions for a growing number of genomes will have an unprecedented effect on the uses of biological resources and the need for access to them. To investigate the diversity of microbial community in swamp, molecular systematic methods were applied. By amplified rDNA restriction analysis (ARDRA) and rDNA partial sequence analysis, $75\%$ of the isolates were known species. In case of uncultured analysis, almost all the selected clones were new species candidate. Especially archea and uncultured bacterial analyses, all clones were new taxon candidates. As for the eukaryotic diversity, several yeast form cultures were isolated from various samples of swamp. Among them, about $60\%$ of the isolates were easily identified. In case of a new species candidate, most strain were included in hymenomycetal yeasts.

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Development of Molecular Biological Methods to Analyze Bacterial Species Diversity in Freshwater and Soil Ecosystems

  • Lee, Dong-Hun;Noh, Sung-Ae;Kim, Chi-Kyung
    • Journal of Microbiology
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    • 제38권1호
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    • pp.11-17
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    • 2000
  • A new method was developed for the rapid analysis of diverse bacterial species in the natural environment. Our method is based on PCR-single-strands-conformation polymorphism (PCR-SSCP) and selective isolation technique of single-stranded DNA. Variable V3 fragments of 16S rDNA were amplified by PCR with bacterial 16S rDNA primers, where one of the primers was biotinylated at the 5'-end. The biotinylated strands of the PCR products were selectively isolated by using streptavidin paramagnetic particles and a magnetic stand, to prevent SSCP analysis producing heteroduplexes from heterogeneous DNA samples. The selected strands were separated by electrophoresis on a polyacrylamide gel, and detected by silver staining. Analysis of PCR products from 8 bacterial strains demonstrated their characteristic DNA band patterns. In addition, changes in the structure of the bacterial community and species diversity in the microcosm treated with phenol could be monitored. After 3 weeks of incubation, phenol and its intermediate, 2-hydroxy-muconic-semialdehyde, were degraded by indigenous bacteria. These dominating bacterial populations were identified as strong bands on an SSCP gel. Therefore, this study provides useful tools for microbial community analysis of natural habitats.

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A Study on Tourist Satisfaction of Rural Tourism Products in Southern Jiangsu Area of China

  • Shan YI;Xu YING
    • 산경연구논집
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    • 제14권9호
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    • pp.13-19
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    • 2023
  • Purpose: Rural tourism, as a green and sustainable new development method, has become a new economic growth point in China's rural revitalization. The current research on rural tourism has not formed a complete and mature theoretical system, especially the study of tourist satisfaction. This paper is based on the perspective of tourist satisfaction and takes rural tourism in southern Jiangsu, China as the research object. Starting from the current situation of rural tourism development in southern Jiangsu, it elaborates on the current situation of rural tourism development in southern Jiangsu. Research design, data and methodology: Through literature analysis, it is concluded that the factors that affect tourist satisfaction are divided into four major aspects: personal factors, perceived effect factors, destination experience factors, and social factors. Design a survey questionnaire from four aspects: diversity, safety, convenience, agreeableness, and draw conclusions through data analysis. Results: From the four dimensions of the survey, tourists pay more attention to the diversity, agreeableness, and convenience of rural tourism products. This requires increasing the development of tourism products and improving the richness and diversity of rural tourism products. Conclusions: Therefore, optimization measures such as continuously implementing local rural cultural construction, establishing brand effects, and increasing policy support have been proposed.

Comparative genetic diversity of wild and released populations of Pacific abalone Haliotis discus discus in Jeju, Korea, based on cross-species microsatellite markers including two novel loci

  • An, Hye-Suck;Hong, Seong-Wan;Kim, En-Mi;Lee, Jeong-Ho;Noh, Jae-Koo;Kim, Hyun-Chul;Park, Chul-Ji;Min, Byung-Hwa;Myeong, Jeong-In
    • Animal cells and systems
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    • 제14권4호
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    • pp.305-313
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    • 2010
  • Pacific abalone Haliotis discus discus is an important fisheries resource in Jeju, Korea. For basic information about its current genetic status in relation to stock enhancement, the level and distribution of genetic variation between wild and released stocks of Pacific abalone in Jeju were examined at nine cross-species microsatellite markers including the use of two novel primers. High levels of polymorphism were observed between the two populations. A total of 146 different alleles were found at all loci, with some alleles being unique. The allelic variability ranged from five to 27 in the wild population and from four to 16 in the released sample. The average observed and expected heterozygosities were estimated to be 0.74 and 0.84 in the wild sample and 0.70 and 0.78 in the released sample, respectively. Although a considerable loss of rare alleles was observed in the released sample, no statistically significant reductions were found in heterozygosity or allelic diversity in the released sample compared to the wild population. Low but significant genetic differentiation was found between the wild and released populations. These results suggest that the intensive breeding practices for stock enhancement may have resulted in a further decrease in genetic diversity, and that the cross-species microsatellite markers used in this study represent a potentially efficient means for further genetic studies, providing beneficial information for the protection and management of H. discus discus.

SNP 정보를 활용한 재래흑염소와 교잡종 염소의 유전적 다양성 및 유연관계 분석 (SNP-based Genetic Diversity and Relationships Analysis of the Korean Native Black Goat and Crossbred Goat)

  • 이상훈;이진욱;이은도;김승창;이성수;김관우
    • 한국산학기술학회논문지
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    • 제21권11호
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    • pp.102-108
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    • 2020
  • 본 연구는 국내 재래흑염소 집단 (당진 계통, 장수 계통, 통영 계통 및 경상대 계통)과 교잡종 염소 집단의 유전적 다양성 및 유전적 유연관계를 조사하기 위해 수행되었다. 각 집단에 존재하는 공통 SNP 45,658개를 이용하여 분석에 이용하였다. 유전적 다양성의 지표가 될 수 있는 기대, 관측 이형접합도는 교잡종, 경상대, 장수, 통영 계통 순으로 나타났다. 집단 사이의 유전적 다양성 정도를 나타내는 분산 성분은 당진과 경상대 계통 사이에서 19.98%로 가장 높게 나타났으며, 장수와 통영 계통 사이에서 8.87%로 가장 낮게 나타났다. 또한, 집단 사이의 유전적 거리는 장수, 통영 계통에서 하나의 분지를 형성하였으며, 당진, 경상대 계통이 하나의 분지로 나타냈다. 또한, 교잡종 집단은 당진, 경상대 계통과 하나의 분지를 이루는 것으로 나타났다. 따라서 본 연구 결과는 국내 계통 간의 불필요한 근친교배와 유전자원 흐름을 줄이기 위한 기초자료 및 국내 재래흑염소 유전자원의 고유성을 나타내는 기초자료로 활용이 가능할 것으로 사료된다.