• 한국축산식품학회지
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• 제38권2호
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• pp.391-402
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• 2018

The aim of the present work was to provide information about Enterococcus strains isolated from pre-packaged chicken samples in Ankara (Turkey), focusing on their prevalence, phenotypic and genotypic characteristics, and antibiotic resistance. We report the first study on the occurrence of antibiotic resistant enterococci in pre-packaged chicken samples in Ankara. A total of 97 suspicious enterococcal isolates were identified from 122 chicken samples. All isolates were identified to species level by phenotypic and molecular methods. In the 16S rDNA sequence analysis, Enterococcus faecium (61.85%) and Enterococcus faecalis (38.15%) were found to be the most frequently detected Enterococcus spp. Of the 97 isolates tested for hemolytic activity, 12.37% enterococcal strains were ${\beta}$-hemolytic. ${\beta}$-Hemolysin was most prevalent among E. faecium (58.33%) compared to E. faecalis (41.66%). Disk diffusion method was used for determining of antibiotic resistance. The analysis of the antimicrobial resistance of the 97 Enterococcus isolates revealed that the resistance to kanamycin (98.96%), rifampicin (80.41%) and ampicillin (60.82%) was most frequent. Furthermore, resistance to erythromycin (38.14%) and ciprofloxacin (34.02%) was also observed. The frequencies of resistance to tetracycline (9.27%), penicillin G (8.24%), and chloramphenicol (3.09%), gentamicin (2.06%) and streptomycin (1.03%) were low. None of the isolates was resistant to vancomycin. Multi-drug resistance was found in 97.93% of Enterococcus strains. E. faecium strains showed a more resistant phenotype than E. faecalis strains according to the antibiotic resistance levels. The results of this study indicated that chicken meat is a potential reservoir for the transmission of antibiotic resistance from animals to humans.

• The Plant Pathology Journal
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• 제33권2호
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• pp.133-139
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• 2017

Tan spot, caused by the fungus Pyrenophora tritici-repentis, is economically important foliar disease in Latvia, Lithuania, and Romania; however, race structure from Baltic States and Romania is not known. In this study, we performed genotypic and phenotypic race characterization of a large collection of P. tritici-repentis isolates from these countries to determine race structure and utilize this information for better disease management and breeding wheat for tan spot resistance. We characterized 231 single spore isolates from Latvia (n = 15), Lithuania (n = 107), and Romania (n = 109) for Ptr ToxA and Ptr ToxB genes using two genes specific primers. A subset (139) of 231 isolates were further characterized for their race structure by inoculating them individually on tan spot wheat differentials set. Majority (83%) of the 231 isolates amplified Ptr ToxA gene suggesting prevalence of race 1 and 2. Further, phenotypic characterization of 139 isolates also showed wide prevalence of races 1 (68%), 2 (8%), 3 (11%), and 4 (5%) were also identified from Baltic States as well as Romania. Eighteen of the isolates (13%) did not seem to be of any of the eight known races as they lacked Ptr ToxA gene but they behaved like either race 1 or race 2, suggesting possibility of novel toxins in these isolates as their virulence tools.

• 식물조직배양학회지
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• 제21권4호
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• pp.233-237
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• 1994

용담의 잎 절편 배양을 통하여 유도된 배발생 캘러스로 부터 식물체의 재분화 체계를 확립하였다. 캘러스는 0.5 mg/L2,4-D, 2 mg/L BAP가 첨가된 MS 배지에서 유도되었으며, 이 캘러스를 2 mg/L P-CPA, 0.5 mg/L 2,4-D 및 0.5mg/L kinetin이 첨가된 SH 배지에 옮겼을 때 배발생 캘러스의 유도가 가능하였다. 배발생 캘러스는 SH 기본 배지에 옮겨 슈트의 증식 및 뿌리 발생을 유도하였다. 재분화 식물체는 피트모스, 펄라이트, 버미클라이트가 2:1:1의 비율로 혼합된 인공 토양에서 순화시킨 후 토양에 활착시켰다. 토양에 활착된 재분화 식물체는 키, 줄기의 모양과 수, 개화기등에서 표현형적 변이를 나타냈다. 세포유전적 분석에서 모식물체와 재분화 식물체의 염색체는 2n=26으로 안정성을 보였는데, 이는 본 연구에서 적용된 재분화 체계가 안정하다는 것을 시사한다.

• 한국작물학회지
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• 제51권2호
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• pp.163-168
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• 2006

Improvement of crop yield can be achieved through understanding genetic variation in reproductive characters and its impact on yield components. The present study was performed to evaluate genetic diversity for reproductive growth characters in exotic germplasm resources and to determine the relationships between developmental and growth periods with yield and yield components in soybean cultivar groups. For phenotypic evaluation such as reproductive and agronomic traits, a total of 80 indigenous and exotic soybean cultivars collected from four different geographical regions (China, Japan, Korea, and Vietnam) were grown from May to November of 2003 at the Seoul National University Farm, Suwon, Korea ($127^{\circ}02'E$ longitude, $37^{\circ}26'N$ latitude). Most of all the characters exhibited wide range of phenotypic variation, of which pod number, seed number, and plant yield showed greater range as compared to other characters. Korean cultivar groups showed greater diversity than the other cultivar groups in seven characters. Correlation analysis showed that days to flowering (DTF) and days to maturity (DTM) had close association with agronomic traits as well as yield and yield components. Both DTF and DTM had positive correlation with the other characters except one hundred seed weight. Stepwise multiple linear regression revealed that seed and pod number were identified as being significant for plant yield. The results in this study indicated wide variation in agronomic traits including DTF and DTM, suggesting the valuable genetic resources in a soybean breeding program.

• Journal of Animal Science and Technology
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• 제50권1호
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• pp.27-32
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• 2008

본 연구의 목적은 1990년 1월부터 2006년 12월사이에 경주한 9,934두의 주파기록, 총 209,725개를 이용하여 국내 더러브렛 경주마의 유전적 개량량을 추정하는데 있다. 주파기록에 대한 연간 표현형 개량량은 1,000m, 1,400m 이하, 1,700m 이상의 경주거리와 전체 자료에서 각각 －0.148초, －0.137초, －0.137초와 －0.139초였으며, 모든 경주거리에서 감소 추세를 나타내었다. 경주년도별 환경효과의 추세는 모든 경주거리에서 표현형 추세와 거의 일치하였으며, 영구환경효과와 기수효과의 추세는 거의 나타나지 않았다. 연간 유전적 개량량은 1,000 m와 전체 자료에서 각각 －0.037과 －0.030초로 다소 낮은 수치였으나 일괄적인 감소 추세를 나타내었다. 따라서 경주마의 질적 향상을 위한 개량계획을 설정하는 것이 시급한 과제라 생각된다.

• 한국수정란이식학회지
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• 제31권4호
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• pp.313-318
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• 2016

The aim of this study was to identify quantitative trait loci (QTLs) influencing teat number traits in an $F_2$ intercross between Landrace and Korean native pigs (KNP). Three teat number traits (left;right;and total) were measured in 1105 $F_2$ progeny. All experimental animals were genotyped with 173 informative microsatellite markers located throughout the pig genome. We detect that seven chromosomes harbored QTLs for teat number traits: genome regions on SSC1;3;7;8;10;11;and 13. Six of fourteen identified QTL reached genome-wide significance. In SSC7;we identified a major QTL affecting total teat number that accounted for 5.6 % of the phenotypic variance;which was the highest test statistic (F-ratio = 61.1 under the additive model;nominal $P=1.3{\times}10^{-14}$) observed in this study. In this region;QTL for left and right teat number were also detected with genome-wide significance. With exception of the QTL in SSC10;the allele from KNP in all 6 identified QTLs was associated with decreased phenotypic values. In conclusion;our study identified both previously reported and novel QTL affecting teat number traits. These results can play an important role in determining the genetic structure underlying the variation of teat number in pigs.

• Asian-Australasian Journal of Animal Sciences
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• 제27권9호
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• pp.1328-1335
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• 2014

Significant SNPs associated with Warner-Bratzler (WB) shear force and sensory traits were confirmed for Hanwoo beef (Korean cattle). A Bonferroni-corrected genome-wide significant association (p< $1.3{\times}10^{-6}$) was detected with only one single nucleotide polymorphism (SNP) on chromosome 5 for WB shear force. A slightly higher number of SNPs was significantly (p<0.001) associated with WB shear force than with other sensory traits. Further, 50, 25, 29, and 34 SNPs were significantly associated with WB shear force, tenderness, juiciness, and flavor likeness, respectively. The SNPs between p = 0.001 and p = 0.0001 thresholds explained 3% to 9% of the phenotypic variance, while the most significant SNPs accounted for 7% to 12% of the phenotypic variance. In conclusion, because WB shear force and sensory evaluation were moderately affected by a few loci and minimally affected by other loci, further studies are required by using a large sample size and high marker density.

• Journal of Microbiology and Biotechnology
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• 제19권12호
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• pp.1679-1687
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• 2009

Three parathion-degrading bacteria and eight pairs of bacteria showing syntrophic metabolism of parathion were isolated from rice field soils, and their genetic and phenotypic characteristics were investigated. The three isolates and eight syntrophic pairs were able to utilize parathion as a sole source of carbon and energy, producing p-nitrophenol as the intermediate metabolite during the complete degradation of parathion. Analysis of the 16S rRNA gene sequence indicated that the isolates were related to members of the genera Burkholderia, Arthrobacter, Pseudomonas, Variovorax, and Ensifer. The chromosomal DNA patterns of the isolates obtained by polymerasechain-reaction (PCR) amplification of repetitive extragenic palindromic (REP) sequences were distinct from one another. Ten of the isolates had plasmids. All of the isolates and syntrophic pairs were able to degrade parathion-related compounds such as EPN, p-nitrophenol, fenitrothion, and methyl parathion. When analyzed with PCR amplification and dot-blotting hybridization using various primers targeted for the organophosphorus pesticide hydrolase genes of previously reported isolates, most of the isolates did not show positive signals, suggesting that their parathion hydrolase genes had no significant sequence homology with those of the previously reported organosphophate pesticide-degrading isolates.

• Fisheries and Aquatic Sciences
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• 제15권2호
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• pp.125-135
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• 2012

This study was carried out to understand the correlation between phylogenetic relationships based on 18S rDNA sequences and growth by salinity of Chlorella-like species. The 18S rDNA sequences of 71 Chlorella-like species which were mainly collected from Korean waters were analyzed. The 18S rDNA sequences of Chlorella-like species were divided into three groups (group A, B and C) and group B was further divided into three subgroups (subgroup B-1, B-2 and B-3). Thirty-seven Chlorella-like species in group A grew well at high salinity (32 psu) but the other groups grew well in freshwater. The sequence identities of the species in group A and B were 97.2-99.5%, but those of 6 species in group C ("Chlorella" saccharophila), which contained group I intron sequences region were 75.0-75.4%. Two representative species of each group were cultured at different salinities (0, 16 and 32 psu) to examine the correlation between the molecular phylogenetic groups and the phenotypic characteristics on cell growth and size by different salinities. The size of cell cultured at different salinities varied according to the species of each molecular phylogenetic group. The size of "Chlorella" saccharophila in group C was bigger and more obviously elliptical rather than that of the other Chlorella-like species. Considering the results on molecular and phenotypic characteristics, the group A and B belonged to Chlorellaceae, but group C was distinctly different from them.

• 아시안잔디학회지
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• 제15권3호
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• pp.127-136
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• 2001

잔디밭에 문제시되는 1년생 화본과 잡초인 바랭이(Digitaria sp.)의 종내 및 종간 변이성을 D. ischaemum과 D. Sanguinalis의 5개 지역종을 대상으로 생육상과 포장조건에서 알아보았다. 포장실험결과 D. sanguinalis와 D. ischaemum의 종내 또는 종간의 잎의 길이와 폭 등을 포함한 형태적 형질에 관련된 유의한 변이성이 관찰되었다. 하지만, 표현형적 변이성에는 실질적 차이는 인정되지 않아 포장조건에서 최초발아시기는 종간 또는 지역종에 관계없이 동일하였다. 4가지의 주야간 온도 차이(25/$25^{\circ}C$, 27.5S/22.5$^{\circ}C$, 30/2$0^{\circ}C$, 15/35$^{\circ}C$)로 조절된 생육상 조건의 실험에서 각 바랭이 종의 발아소요일수에 관한 종간 또는 종내의 변이성은 없었다. 따라서, 잔디밭에서 효율적인 바랭이 방제를 위해 특정지역에서 최초 발아시기에 관련된 예측모델은 타 지역에도 동일하게 적용 가능할 것으로 생각된다.