• 한국작물학회지
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• 제54권4호
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• pp.346-350
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• 2009

The cultivated radish (Raphanus sativus L.) is a major vegetable crop in the world wide and fast-growing species that grows inhabitats of six continents. It is very important to determine hybrid seed purity in the production of hybrid Brassica vegetable seeds to avoid unacceptable contamination with self-inbred (sib) seeds. The use of random amplified polymorphic DNA (RAPD) markers for evaluating seed purity in $F_2$-hybrid radish cultivars demonstrated. One hundred eighty seeds from the F1 male and female harvest were subsequently screened for seed purity using 13 primers. The 13 primers result in 17 cultivar-specific bands and 23 variable RAPD bands scored for cultivar. RAPD analysis of hybrid seeds from the harvest revealed 128 seeds tested except underdevelopment and decayed seeds were sibs. Especially, $F_2$ hybrids of radish, OPC13, OPD20 were presented clear hybrid bands. It maintains higher than average level of genetic diversity compared with their correspondent parents. RAPD amplification of DNA extracted from germinated individuals from the female harvest reveal that 10 of 208 seeds tested were self-inbred (4.8%). RAPD analysis of hybrid seeds from the male harvest revealed 7 of the 208 seeds tested were sibs (3.4%). The RAPD may lead to a better insight in to the hybrid seed purity.

• Weed & Turfgrass Science
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• 제5권3호
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• pp.144-154
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• 2016

Goosegrass [Eleusine indica (L.) Gaertn] has been a nuisance to growers in Malaysia due to its increased resistance to commercial herbicides, rapid growth and dissemination, and interference with agricultural practices. In the course of developing an apt integrated management to control goosegrass, more information of this weed is needed. The aim of this study was to look into variations among the goosegrass ecotypes sampled throughout Malaysia from the aspects of genotype and phenotype. Sequence-related amplified polymorphism (SRAP) markers were employed in investigating the genetic diversity and relationships among the 18 goosegrass ecotypes. Consequently, 5 primer combinations amplified 13 fragments with the polymorphism rate of 69.23%. At 74% similarity, the ecotypes were clustered into 6 groups. Phenotypic variability of the goosegrass ecotypes was assessed by observing their morphology, growth and seed traits. Goosegrass ecotypes were sorted into 3 major groups at the genetic distance (DIST) of 0.37. Concurrences of the evaluated genetic distance, ecotypes with the closest and most distant relationships were assembled together in Group I which showed high variation even among ecotypes in the same group. Results obtained thus implied high molecular and morphological variations of the goosegrass ecotypes in Malaysia.

• 한국자원식물학회지
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• 제32권3호
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• pp.244-253
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• 2019

In crop breeding program, information about genetic dissimilarity on breeding resources is very important to corroborate genealogical relationships and to predict the most heterozygotic hybrid combinations and inbred breeding. This study aimed to evaluate the genetic variation in Kenyan sunflower breeding lines based on simple sequence repeat (SSR). A total of 83 alleles were detected at 32 SSR loci. The allele number per locus ranged from 2 to 7 with an average of 2.7 alleles per locus detected from the 24 sunflower accessions and the average value of polymorphic information contents (PIC) were 0.384. A cluster analysis based on the genetic similarity coefficients was conducted and the 24 sunflower breeding resources were classified into three groups. The principal coordinates (PCoA) revealed 34% and 13.38% respectively, and 47.38% of total variation. It was found that the genetic diversity within the Kenyan sunflower breeding resources was narrower than that in other sunflower germplasm resources, suggesting the importance and feasibility of introducing elite genotypes from different origins for selection of breeding lines with broader genetic base in Kenyan sunflower breeding program.

• ALGAE
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• 제34권3호
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• pp.187-198
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• 2019

The exploration of seaweed diversity in poorly studied habitats has often led to the discovery of new species. Sand-covered rocks are an example, as they received less attention than sand-free rocky intertidal habitats during seaweed diversity surveys in Brazil. In sand-covered rocks from Espirito Santo and Rio de Janeiro we found an alga whose morphology was unique among rhodomelacean species previously reported in Brazil. With the aim to clarify the taxonomic identity of this species we studied its morphology, as well as its phylogenetic relationships. Molecular analyses resolved this species in the genus Alsidium (tribe Alsidieae) and differed from sequenced congeners with divergences ${\geq}2.5$ and 4.2% in the rbcL and cox1 genes, respectively. Morphological characters were in agreement with the genus Alsidium, and differed from other species currently recognized in the genus. The species consisted of a basal crust and scarcely branched erect axes with seven pericentral cells covered by a continuous layer of cortical cells. Reproductive structures were formed on clusters of short determinate branches. Therefore, the new species A. oliveiranum is proposed based on morphological and molecular evidence. Our findings contribute to better understand the diversity of the tribe Alsidieae, which is particularly diverse in the Americas.

• Asian-Australasian Journal of Animal Sciences
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• 제27권11호
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• pp.1562-1570
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• 2014

The effects of Lactobacillus mucosae (L. mucosae), a potential direct fed microbial previously isolated from the rumen of Korean native goat, on the rumen fermentation profile of brewers grain were evaluated. Fermentation was conducted in serum bottles each containing 1% dry matter (DM) of the test substrate and either no L. mucosae (control), 1% 24 h broth culture of L. mucosae (T1), or 1% inoculation with the cell-free culture supernatant (T2). Each serum bottle was filled anaerobically with 100 mL of buffered rumen fluid and sealed prior to incubation for 0, 6, 12, 24, and 48 h from which fermentation parameters were monitored and the microbial diversity was evaluated. The results revealed that T1 had higher total gas production (65.00 mL) than the control (61.33 mL) and T2 (62.00 mL) (p<0.05) at 48 h. Consequently, T1 had significantly lower pH values (p<0.05) than the other groups at 48 h. Ammonia nitrogen ($NH_3$-N), individual and total volatile fatty acids (VFA) concentration and acetate:propionate ratio were higher in T1 and T2 than the control, but T1 and T2 were comparable for these parameters. Total methane ($CH_4$) production and carbon dioxide ($CO_2$) were highest in T1. The percent DM and organic matter digestibilities were comparable between all groups at all times of incubation. The total bacterial population was significantly higher in T1 (p<0.05) at 24 h, but then decreased to levels comparable to the control and T2 at 48 h. The denaturing gradient gel electrophoresis profile of the total bacterial 16s rRNA showed higher similarity between T1 and T2 at 24 h and between the control and T1 at 48 h. Overall, these results suggest that addition of L. mucosae and cell-free supernatant during the in vitro fermentation of dried brewers grain increases the VFA production, but has no effect on digestibility. The addition of L. mucosae can also increase the total bacterial population, but has no significant effect on the total microbial diversity. However, inoculation of the bacterium may increase $CH_4$ and $CO_2$ in vitro.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.136-139
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• 2003

This study is to observe the occurrence of heterotrophic bacteria in terms of free chlorine residuals in two different water distribution system which belongs to both K and Y water treatment plant of S city of Korea. The data analyzing in distribution systems (DS) shows that the free chlorine residuals decrease from 0.10 to 0.56 mgmg/L for K, and 0.51 to 0.78 mg/L for Y. The decay of free chlorine is clearly higher in both March and August than those of in January. The HPC in DS are ranged from 0 to 40 CFU/mL for K, 0 to 270 CFU/mL for Y, on R2A medium. In particular, its level is relatively high at consumers ground storage tanks, taps and point-of-end area of Y. The predominant genera is studied in distribution systems are Acinetobacter, Sphingomonas (branch of Pseudomonas), Micrococcus, Bacillus, Staphylococcus. The diversity of heterotrophic bacteria increase in the end-point area. Most of them are either encapsulated cells or cocci of gram-positve. In conclusion, the point-of-end area in distribution systems shows the longer flow distance from water treatment plants, the greater diversity and higher level of heterotrophic bacteria due to the significant decay of free chlorine residuals.

• 한국산림과학회지
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• 제96권6호
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• pp.667-675
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• 2007

I-SSR 표지자를 이용하여 영월지역의 줄댕강나무 2개 집단의 유전적 다양성과 공간구조가 조사되었다. 줄댕강나무는 분포가 제한되어있고 집단크기가 작음에도 불구하고 개체 수준에서 추정된 유전변이는 다른 관목류와 유사한 수준으로 판단되었다.(S.I.=0.336, h=0.217). Genet 수준에서 조사된 유전다양성 역시 개체 수준의 값과 큰 차이가 없었다(S.l.=0.339, h=0.219). 전체 유전변이의 약 18.7%가 집단 간 차이로 나타나, 다른 관목류에 비해 다소 높거나 비슷한 수준이었다. $N_G/N$ 값과 Simpson's index로 추정된 유전자형 다양성 역시 다른 관목류에 비해 높았다($N_G/N=0.729$. $D_G=0.988$). 한 genet의 최대직경은 5.5 m로 비교적 작게 나타났다. 높은 수준의 유전자 및 유전자형 다양성과 genet의 작은 직경 크기는, 무성번식이 줄댕강나무 집단의 유전적 구성에 차지하는 비중이 그렇게 크지 않음을 보여주었다. 개체 및 genet 수준에서 큰 차이 없이, 약 12-18 m 거리 내에 분포하는 개체 간에 자기상관성이 인정되었다. 줄댕강나무 집단의 현지외 보전을 위한 표본 추출 시, 연속 분포하는 집단에서는 최소 18m 이상의 간격을 두는 것이 좋고, 소규모 단편으로 분리되어 분포하는 경우 최대한 많은 단편으로부터 표본을 채취하는 것이 효율적일 것으로 판단되었다.

• 한국전자파학회지:전자파기술
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• 제5권4호
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• pp.3-17
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• 1994

m-분포 페이딩과 임펄스 잡음이 함께 존재하는 환경에서 다이버시티 수신기법으로 수신했을 때의 QPSK 및 Q QDPSK 신호의 오율식을 유도한 후 이를 수치계산하여 신호의 오율성능을 분석하였고 가우스 잡음 환경일 때 의 성능과 비교하였다. 그 결과 임펄스 잡음이 강할수록 오융성능은 열화되며 QDPSK 신호일 때의 열화정도가 QPSK 신호일 때 보 다더 심함을알수있었다. 또한 다이버시티 수신기볍을 이용하면 가우스 잡음과 페이딩이 함께 존재하는 환경에서 뿐만 아니라 임펼스 잡음과 페이딩이 함께 존재하는 환경에서도 오율성능을 개선시킬 수 있고 다이버시티 기법을 이용하므로서 얻을 수 있는 개선은 CNR면에서 약 1여B -l&1B가 된다는 것도 얄 수 있었으며 다이버시티 기볍 중에서는 최대 비 합성 다이버시티 기법이 가장우수함도 확인하였다. 임펄스 잡음과 Rayleigh 페이딩이 함께 존재하는 환경에서 다이버시티 수신 기법과 부호화 기볍을 함께 이용 할 경우에는 다이버시티 수신 기법만을 이용할 때 보다 오율생능이 CNR변에서 약 12dB -l&1B만큼 개선됨을 알 수 있었으며 BCH 부호화를 이용할 때 보다 RS 부호화를 이용할 때가 CNR면에서 약 2dB정도 개선된다는 것도 알 수 있었다.

• 환경생물
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• 제39권4호
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• pp.559-572
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• 2021

가을 한국 남해 서부 해역의 수괴분석 및 식물플랑크톤 군집의 공간분포 특성을 이해하기 위해 2021년 9월 15개 정점의 표층과 엽록소 a 최댓층(CML)을 대상으로 조사하였다. 결과, 수괴는 고온, 저염의 연안수(CW), 고온, 고염의 쓰시마난류(TWC) 및 이 두 수괴의 혼합특성을 보이는 혼합수(MW)로 구분되었다. 용존산소 포화도는 표층에서는 95% 이상을 보이지만, CML 일부 해역은 낮은 불포화 상태를 보였고, 탁도는 표층과 저층 모두에서 농도가 높았다. 엽록소 a 농도는 표층이 0.90±0.43 ㎍ L^-1 변동 폭으로 연안수에서 1.1 ㎍ L^-1 이상, 혼합수에서 1.0 ㎍ L^-1 전후, 그리고 쓰시마난류에서 0.5 ㎍ L^-1 이하를 나타내었다. CML은 1.64±0.54 ㎍ L^-1 변동 폭으로 표층보다 약 2배 높았다. 식물플랑크톤 종 조성은 31속 57종으로 규조류가 57.8%, 와편모조류가 35.1%, 규질편모조류 5.3%, 그리고 은편모조류가 1.8%로 단조로웠다. 현존량은 표층이 4.6±7.6 cells mL^-1 변동 폭으로 연안에서 30 cells mL^-1 이상, 혼합수에서 2~5 cells mL^-1, 그리고 쓰시마난류에서 2 cells mL^-1 이하를 나타내었다. CML은 5.7±8.4 cells mL^-1 변동 폭으로 표층보다 다소 높았다. 5% 이상 우점율을 보이는 우점종은 표층에서 Rhizosolenia flagilissima f. flagilissima, Skeletonema costatum-ls, Nitzschia sp./small size가 각 8.4%, 6.1%, 5.2% 순이었고, CML은 Rh. flagilisima f. flagilissima가 12.0%의 우점율을 나타내었으나, 낮은 현존량으로 우점종에 대한 의미 부여가 어려웠다. 다양도 지수는 표층이 2.36±0.40 변동 폭으로 쓰시마난류에서 높고, 혼합수에서 낮았고, CML은 2.29±0.52 변동 폭으로 표층보다 다소 낮았다. 우점도 지수는 표층이 0.50±0.15 변동 폭으로 혼합수에서 0.5 이상, 쓰시마난류에서 0.5 이하로 다양도와 다른 특성을 보였다. 상관분석 및 주성분 분석 결과는 식물플랑크톤 현존량은 연안수 및 혼합수에서 높고, 높은 탁도를 보인 일부 혼합수 및 쓰시마난류에서 낮은 것에서, 각수괴의 확장 및 혼합 정도에 따라 식물플랑크톤 군집의 출현 및 분포에 커다란 영향을 미치는 것으로 판단되었다.

• 한국작물학회지
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• 제58권4호
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• pp.336-346
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• 2013

Amaranth (Amaranthus sp. L.) is an important group of plants that includes grain, vegetable, and ornamental types. Centers of diversity for Amaranths are Central and South America, India, and South East Asia, with secondary centers of diversity in West and East Africa. The present study was performed to determine the genetic diversity and population structure of 75 amaranth accessions: 65 from South America and 10 from South Asia as controls using 14 SSR markers. Ninety-nine alleles were detected at an average of seven alleles per SSR locus. Model-based structure analysis revealed the presence of two subpopulations and 3 admixtures, which was consistent with clustering based on the genetic distance. The average major allele frequency and polymorphic information content (PIC) were 0.42 and 0.39, respectively. According to the model-based structure analysis based on genetic distance, 75 accessions (96%) were classified into two clusters, and only three accessions (4%) were admixtures. Cluster 1 had a higher allele number and PIC values than Cluster 2. Model-based structure analysis revealed the presence of two subpopulations and three admixtures in the 75 accessions. The results of this study provide effective information for future germplasm conservation and improvement programs in Amaranthus.