• Journal of Ginseng Research
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• 제40권2호
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• pp.127-134
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• 2016

Background: Rhizospheric fungi play an essential role in the plantesoil ecosystem, affecting plant growth and health. In this study, we evaluated the fungal diversity in the rhizosphere soil of 2-yr-old healthy Panax notoginseng cultivated in Wenshan, China. Methods: Culture-independent Illumina MiSeq and culture-dependent techniques, combining molecular and morphological characteristics, were used to analyze the rhizospheric fungal diversity. A diffusion test was used to challenge the phytopathogens of P. notoginseng. Results: A total of 16,130 paired-end reads of the nuclear ribosomal internal transcribed spacer 2 were generated and clustered into 860 operational taxonomic units at 97% sequence similarity. All the operational taxonomic units were assigned to five phyla and 79 genera. Zygomycota (46.2%) and Ascomycota (37.8%) were the dominant taxa; Mortierella and unclassified Mortierellales accounted for a large proportion (44.9%) at genus level. The relative abundance of Fusarium and Phoma sequenceswas high, accounting for 12.9% and 5.5%, respectively. In total,113 fungal isolates were isolated from rhizosphere soil. They were assigned to five classes, eight orders (except for an Incertae sedis), 26 genera, and 43 species based on morphological characteristics and phylogenetic analysis of the internal transcribed spacer. Fusarium was the most isolated genus with six species (24 isolates, 21.2%). The abundance of Phoma was also relatively high (8.0%). Thirteen isolates displayed antimicrobial activity against at least one test fungus. Conclusion: Our results suggest that diverse fungi including potential pathogenic ones exist in the rhizosphere soil of 2-yr-old P. notoginseng and that antagonistic isolates may be useful for biological control of pathogens.

• 한국육종학회지
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• 제41권4호
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• pp.369-376
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• 2009

Cowpea might have been introduced from China to Korea and cultivated for several hundred years but it has never been a staple food crop in Korea. In this study, genetic diversity of 492 Korean cowpea landrace accessions that have passport information was estimated using six SSR markers. The mean of Weir's gene diversity was 0.665 from all accessions investigated in the study. Cowpea gene diversity of six local provinces in Korea was ranged from 0.370 in accessions of Gangwon to 0.680 in Jeonra provinces. Low gene diversity of the cowpea genepool of Gangwon province was probably derived from relatively few introductions. Especially SSR markers VM36 and VM39 seem to be good markers to distinguish the Gangwon accessions from others by occurring at a specific locus with higher than 78% of allele frequency. Except for the Gangwon province with the low genetic diversity, gene diversity of cowpea accessions from other provinces was ranged from 0.600 to 0.680 indicating no big differences among provinces. Distribution pattern of the allele frequencies was similar among the other provinces. This may reveal that Korean farmers might exchange cowpea seeds easily with even their neighbors with geographical barriers. A core collection, 100 landraces, ca. 20% of base collection, was developed at the 70% of a similarity coefficient level using random sampling approaches after stratification of the entire landrace collection based on the phenetic dendrogram. The variability of SSR in the base and core collections of Korean cowpea landrace was compared by calculating Weir's gene diversity. The mean of Weir's gene diversity of the core was 0.707 while that of the base collection was 0.665. The higher diversity index in the core collection indicates that it maintains the initial variability and well represents the base collection. The core collection included one of determinate accession (IT 216155) and two of no branching type accessions (IT 103959 and IT 161024). The core collection could be used to guide more efficient management and utilization of the entire collection. This core collection should be revised periodically as additional accessions are collected and further characterization is conducted.

• 한국통신학회논문지
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• 제28권10C호
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• pp.995-1006
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• 2003

무선 통신 시스템은 전자파 신호의 전파 특성과 주위 환경/장애물에 의해 다중 경로 페이딩을 겪게 되어 수신 신호의 급격한 전력 감쇄가 생길 수 있음은 잘 알려져 있는 사실이다. 한편으로 송신기에서 생성된 하나의 동일한 송신 신호가 여러 경로를 통해서 해당 수신기에 도달하므로 이점을 적극적으로 활용하면 데이터 수신 성능을 향상 시킬 수 있는데 이것의 한가지 방법이 레이크 신호처리 기법이다. 본 연구는 PN (pseudo noise) 수열을 사용하여 주파수대역 확산을 구현하는 무선통신 수신기에서 레이크 신호처리 기법에 대해서 연구하였다. 기존의 고정 PN 레이크 복조기는 다중 경로 페이딩 채널의 임펄스 응답 계수의 공액 복소수 값을 계수로 하는 유한 길이 디지털 필터에 의해 수신 신호론 처리한 후, PN 복조 과정을 거쳐 데이터 신호를 재생하게 된다. 본 연구에서는 기존의 PN 복조 과정을 대체하는 최적 복조기의 개념 및 적응 설계 기법을 제안하였다. 제안된 최적 레이크 복조기에 대해 이론적인 성능 분석을 수행하였으며, 컴퓨터 모의 실험을 통해 유도된 결과들의 타당성을 검증하였다. 결과로 새로운 최적 레이크 신호처리기법을 통해 기존의 고정 PN 레이크 복조기에 비해 심볼평균제곱오차가 10dB 이상의 월등한 성능 향상이 가능함을 보였다. 또한 다중 경로 신호의 결합과 PN 복조를 동시에 한 복조 심볼 구간 안에서 수행하는 통합 복조기에 비해서도 약 10 dB 정도의 성능 향상이 있었다. 그리고 최적 레이크 복조기의 심볼평균제곱오차가 이론적인 한계치인 백색잡음 채널에서 QPSK 복조기의 심볼평균제곱오차에 매우 근접함을 보였다.

• Journal of Microbiology
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• 제45권6호
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• pp.479-484
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• 2007

Bacterial communities at 10 cm, 100 cm, and 200 cm depths in a 100-year-old lead-zinc tailing heap were evaluated by constructing 16S rRNA gene libraries. In total, 98 operational taxonomic units (OTUs) were identified from 193 clones at a 3% sequence difference level. The OTU number and species richness decreased with the depth. Species composition was significantly different between the three libraries. Fifty-seven percent of the examined clones were Acidobacteria and 27% belonged to Proteobacteria. Other sequences included Chloroflexi, Firmicutes, Chlamydiae, Actinobacteria, Gemmatimonadetes, Nitrospira, and three unclassified OTUs. Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and Actinobacteria were mainly distributed in the rhizosphere of naturally colonizing plants; however, Deltaproteobacteria, Acidobacteria, and Chloroflexi tended to inhabit the deeper tailings (below the 100 cm-depth).

• 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.

• 한국동물위생학회지
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• 제33권4호
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• pp.353-359
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• 2010

Nucleotide sequences of mitochondrial DNA (mtDNA) of 19 leopard cats (Prionailurus bangalensis euptilura) obtained from Seoul grand park zoo in South Korea were determined for analysing genetic diversity. In the leopard cats, 3 haplotypes of the partial cytochrome b sequences (603 base-pairs, bp) were identified. Haplotypes obtained from those genes showed existences of at least 3 maternal lineages of leopard cats in Korea. Tamura-Nei nucleotide distance among 3 haplotypes were 0.00. Molecular phylogenetic tree showed the similar clustering of haplotypes for genes. Meanwhile, no individual variations within the leopard cats in S. Korea. Genetic surveillance system of leopard cats in S. Korea is warranted for maintaining biological conservation.

• The Korean Journal of Ecology
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• 제14권3호
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• pp.257-271
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• 1991

Two types in the species-importance, one type of carpinus laxiflora, carpinus tschonoskii, quercus serrata, quercus grosseserrata and pnus densiflora community and another type of abeies koreana community classified by zurich-montpellier method, were recognized based on the data from 81 sample plots. The forme species sequence-importance curves were coincidred with the ideal curve calculated by preston's lognormal-distribution theory(1948), with small variations among five communities, and the latter with that of motomura's niche pre-emption hypothesis(1932). It seems that plant community classified by phytosociological method based on the unit concept coincide with the vegetation type recognized by species population analyse based on the continuum concept and the dominance-diversity reflrcts on the difference in the coenocline among their plant communities.

• International Journal of Industrial Entomology and Biomaterials
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• 제24권2호
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• pp.57-61
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• 2012

The Indian Oak Tasar silkworm, Antheraea proylei J. is a beneficial insect with great economic importance in India for its silk production. In this study, six populations of Antheraea proylei and A. frithi Moore (as an out group) were subjected to inter simple sequence repeat (ISSR) marker analysis in order to assess its genetic diversity. Fifteen ISSR primers produced 91 markers among different breeds of A. proylei and A. frithi of which 89 are polymorphic, generating 97.8% polymorphism. The dendrogram constructed using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) and cluster analysis made using Nei's genetic distance resulted in the formation of one major group containing four sub-groups separating the breeds. This result suggests that ISSR amplification is potentially useful for molecular characterization of oak tasar silkworm genotypes.

• 한국자원식물학회지
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• 제10권3호
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• pp.258-264
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• 1997

The introduction of molecular biology methodologies to plant improvement programs offers an invaluable opportunity for extensive germplasm characterization. We have applied the developed technique of random amplification of polymorphic DNA(RAPD)to the analysis of evaluating genetic diversity among Korean wild Codonopsis lanceolata. A total of 340 polymorpic hands were gernerated on agarose- and polyacrylamide-gel by 19 primers of abitrary sequence. grouped by cluster analysis using sample matching coefficients of similarity. Among of the samples. the minimum genetic distance value was obtained between sample no. 1(Girisan) and no. 2(Girisan), and the largest value between sample no. 11(Sulaksan) and no. 17(Sulaksan).In separate cluster dendrograms based on agareose - and polyacryamide-gel. some differences were observed; In the case of agarose gel,41 samples could be devided into 7 groups at below about 0.44 level of distance. However they were divided into 6 gourps at below about 0.40 level of distance in the case of polyacrylamide gel. These results showed that polymophic data in agrose were not grouped to wild plant selected from each mountainous district except for wild plants selected from Sulaksan and Chiaksan. We believe that polyacrylamide-RAPD is a superior method for detecting DNA polymorphism compared to agarose-RAPD method.