• Asian Journal of Turfgrass Science
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• v.18 no.3
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• pp.141-148
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• 2004

In this report, several factors such as infection time and concentration of bacterial suspension, influencing on transient gene expression in Agrobacterium-mediated transformation were evaluated. An appropriate concentration (O.D 600nm = 1.0-1.2) of bateria and 30 min of infection time showed a higher level of GUS expression. To improve transformation efficiency (TE), friable embryogenic calli (FEC) were bombarded by tungsten particles without plasmid DNA, and then co-cultivated with A. tumefaciens LBA4404 which contains pTOK233 super binary vector, carrying neomycin phosphotransferase (NPTII), hygromycin phosphotransferase (hpt) and$\beta-glucuronidase$ (GUS) genes. Three days after co-cultivation with A. tumefaciens and particle bombardment, FEC cultures were transferred to the selection medium (SM: MS medium supplemented with BA 1mg/l, hygromycin 100mg/l, cefotaxime 250 mg/l and vancomycin 200mg/l). They were cultured for 2 weeks and then transferred to the second SM containing hygromycin 50mg/l, cefotaxime 200 mg/l and vancomycin 100mg/l. Later, stable GUS expression was detected 4 to 6 weeks after transfer to the SM. Further, TE from Agrobacterium-mediated transformation after particle bombardment increased to about 3-folds compared with Agrobacterium-mediated transformation without particle bombardment. In the present study, we established an efficient transformation protocol of zoysiagrass by using A. tumefaciens in the combination with particle bombardment for the first time.

• Korean Journal of Breeding Science
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• v.43 no.1
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• pp.68-80
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• 2011

This study was conducted to investigate characteristics and variations of rice panicle traits for breeding temperate japonica varieties adapted to tropical environment. Eleven panicle traits were investigated from nine Korean rice varieties cultivated in Korea and wet season of the Philippines. Tested cultivars were composed of six temperate japonica varieties, three Tongil-type varieties, and one indica variety bred in the Philippines. The number of spikelets on secondary rachis branches (SRBs) was the most variable trait in both environments, while the mean number of spikelets on a primary rachis branch (PRB) was the least variable. Compared with PRB-related traits, SRB traits showed higher correlation with the number of spikelets per panicle. Compared with the plants grown in Korea, the number of spikelets on SRBs, the number of SRBs, spikelets, and rachis branches per panicle were decreased more than other traits in the Philippines. According to path analysis, the number of spikelets on SRBs per panicle affects the number of spikelets per panicle more than the number of spikelets on PRBs per panicle. Climatic factors such as growth duration, cumulative mean temperature, and integrated solar radiation were highly correlated with the relative rate of number of spikelets per panicle. To breed temperate japonica rice varieties adapted to tropical environment, it would be important to select lines which maintain proper growth duration and spikelets on SRBs in target region.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.19-25
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• 2006

With the use of Agrobacterium and gene-gun, cold regulated gene (BN115) has been injected in Chrysanthemum leaf disc and transgenic plants have been produced successfully on the selection media containing phytohormone. To determine the presence of the transferred cold regulated gene (BN115) in the transgenic Chrysanthemum, PCR-amplification indicated the presence of that gene. Real-Time PCR for confirmation of the putative transgenic plants was established. The copy number of cold regulated gene (BN115) is extrapolated on the basis of a standard curve. Serial dilutions of known number of gene copies were in triplicates. In this diagram, PCR cycles are plotted against the fluorescence intensity. The cycle at which the fluorescence reaches a threshold cycle is inversely proportional to the starting amount of target DNA.

• Korean Journal of Ichthyology
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• v.2 no.1
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• pp.47-52
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• 1990

Anew species of cyprinid fish Acheilognathus koreensis is described from specimens collected in several rivers of southern part of Korea. In general aspect it is similar to A. liηzbata but differs form this by having large snout length, narrow interorbital width and characters of early developmental stage. The new species is distinguished from A. signifer by color parttern of dorsal and anal fin ray in male, and egg form and ovipositor length in female.

• Korean Journal of Medicinal Crop Science
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• v.12 no.6
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• pp.448-453
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• 2004

Transformed roots of Schisandra chinensis were obtained following co-cultivation of in vitro cultivated plantlet segments with Agrobaterium rhizogens ATCC15834. This root was examined for its growth and gomisin J contents under various culture conditions. Among the six basal culture media tested, WPM (Lloyd & McCown, 1980) medium supplemented with 5% sucrose was the best roots growth 6.2 (g D.W/flask) and gomisin J accumulation 1.56 $(X10^{-3}\;ug/g\;D.W)$. Initial inoculum size correlated with the yield of biomass while gomisin J contents was not affect. Gomisin J production was influenced by the initial sucrose concentration and the highest production yield was achieved at the concentration of 7%. The optimal shaking speeds for roots growth and gomisin J production was 120 and 140 rpm, respectively.

• Korean Aquaculture
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• v.14 no.1
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• pp.63-66
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• 2002

담수산 rotifer, Brachionus calyciflorus는 담수어류의 종묘생산시 초기 자어의 먹이생물로 많이 이용되고 있다. 특히, 이 종의 암컷은 수컷에 관계없이 암컷이 난을 생산하는 처녀생식과 수컷과의 교미에 의해 암컷이 수정란(내구란)을 형성하는 유성생식으로 나뉘어진다. 한편, 유성생식에 의해 형성된 내구란은 두터운 2차 난막으로 싸여져 있어 외부환경이 부화에 적합하지 않으면 강한 내구성을 지니고 있어 휴면 상태를 계속 유지한다. 이러한 내구란은 종의 유전적 형질을 효율적으로 보관할 수 있을 뿐만 아니라 대량배양하기 위한 종자 및 수산 생태 독성학의 실험재료로 이용할 수 있다. 또한 내구란은 Artemia cyst처럼 쉽게 부화시켜 자어에 직접 먹이로 공급할 수 있는 장점으로 인해 rotifer 대량배양에서 오는 유해 세균과 원생동물에 의한 자치어의 2차 감염을 방지 할 수 있다. 이처럼 rotifer, B. calyciflorus 내구란은 여러 가지 용도로 이용 가능하기 때문에 내구란을 대량생산할 수 있는 조건을 규명하는 것도 중요하다. 그리고 생산된 내구란을 사용 목적에 따라서 간편하게 이용하기 위해서는 내구란을 제품으로 만드는 것도 매우 중요하다. 따라서 본 내용은 담수산 rotifer 내구란을 상품화하기 위한 방법으로 내구란의 대량생산과 보존방법에 대해서 설명하고자 한다.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.339-346
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• 2007

Pollen germination viability is an essential factor to produce seeds from pollination and fertilization, which are required to maintain plant generation. In this study, we tried to identify the effect of boric acid on pollen germination and tube grouch in non-transgenic and transgenic plants expressing monoclonal antibodies (anti-colorectal cancer mAb CO17-1A, anti-breast cancer mAb BR55, and anti-rabies virus mAb57). The pollen of non-transgenic plant was treated with different concentration of boric acid (0, 5, 10, 15, 20, $40{\mu}g/mL$) in germination buffer to investigate its effect on in vitro pollen germination. At $20{\mu}g/mL$ of boric acid, tile pollen germination rate was the highest (49.5%) compared to other concentrations. In general, the germination rate significantly increased 3-10 folds in boric acid ($20{\mu}g/mL$) treated group in non-transgenic and transgenic plants. Also, the pollen tube length increased in boric acid ($20{\mu}g/mL$) treated groups. In the treated group, the pollen tube length increased until 3 h boric acid treatment and decreased after the 3 h, indicating that the 3 h is the most appropriate incubation time period. Western blot analysis showed that the mAb transgene expression was more stable in leaf than pollen in transgenic plants. This study suggested that $20{\mu}g/mL$ of boric acid is ideal concentration to induce in vitro pollen germination of transgenic plants expressing therapeutic monoclonal antibodies, indicating stable pollination and fertilization in transgenic plants.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.74-84
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• 2001

The early developmental stages, growth and morphological changes of the Korean bullhead, Pseudobagrus fulvidraco, were studied from a series of reared specimens. Details of the early developmental stages are illustrated with special reference to morphological transformations. Egg and sperm of Korean bullhead were obtained from mature adults under hormonal treatment, fertilized artificially, and incubated in the aquarium. The incubation period of fertilized eggs was 55 to 66 hours at a temperature of 24.9${\pm}$0.34$^{\circ}$. Larvae were fed successively with Artemia salina and Daphnia magna for 2 to 15 days and artificial food after 20 days. Fertilized eggs were adhesive and spherical with a diameter of 2.04mm(n = 100). The mean total length of newly hatched larvae was about 4.92${\pm}$0.33 mm. Mouth opening occurred on one-day-old yolk-sac larvae, and initial feeding was observed on the third day after hatching. The morphological transitions from larvae to juvenile and juvenile to young stages occurred when the fish reached about 17 mm in total length (about 13days after hatching) and about 32 mm in total length (about 30 days after hatching), respectively. Many changes in proportion of body parts to total length were observed at about 7~8 mm and 30~32 mm, corresponding to the transformations from larvae to juvenile and from juvenile to young, respectively. In comparing relative growth of each body part against total length, those characteristics related to head parts showed positive growth in the pre-larval stages, while those concerning mobile abilities showed positive growth in the post-larval stage.

• Korean Journal of Plant Taxonomy
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• v.36 no.3
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• pp.163-187
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• 2006

Taxonomic studies were conducted to evaluate the interspecific relationships in Viola albida var. albida and its related taxa using seven populations for morphology, palynology and anatomy. Molecular phylogenetic studies were also examined in 28 populations including 19 Korean, four Chinese, two Japanese, one American population and two outgroups using nrITS, and 27 populations except V pinnata for trnL-F region of chloroplast DNA. Morphological differences was observed among seven populations of three species in leaf shape, but characters such as serrate number of leaf margins, petal size, pistil shape were showed overlap between populations. Pollen shape of seven populations was monad and grain shape on the polar axis was semi-angular. Morphology of aperture was tri-colporate, and the surface sculpturing was scabrate in rugulate. The grain shape of equatorial view of five populations was prolate whereas V albida var. taknhashii type 1 and V albida var. chaerophylloides type 3 were subprolate. The anatomical characters of rnidvein of leaf, petiole, peduncle, root were also described for the species. The stomatal apparatus of the leaves was observed only in abaxial surface, and the number of stoma per unit ($mm^2$) were abundant in incised than lobate or cleft margin of the leaves. The nrITS analysis shows that V. pinnata and V. dissecta was monophyletic and occupied a basal position in the V. albida var. albida and its related taxa. The other clade including infraspecific populations of V. albida, and V. eizanensis was paraphyletic. The trnL-F noncoding region analysis was similar to the ITS tree. According to the above observations in morphology, palynology, anatomy, and molecular phylogenetic analysis, the significant differences were not found except for leaf shape in Viola albida var. albida and its related taxa, therefore V. albida var. takanhashii and V. albida var. chaerophylloides were considered to be an infraspecific taxa of V. albida var. albida rather than an independent species, subvariety or variety of V. pinnata and V. dissecta.

• Journal of Life Science
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• v.31 no.12
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• pp.1088-1093
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• 2021

Jeju horse (Equus ferus caballus) is a Korean horse breed that has been native to Jeju Island for a long time. Jeju horses are used as racehorses, and their racing ability is a major economic trait. The role of the myostatin (MSTN) gene in skeletal muscle mass has been studied in various mammals, and mutations in the MSTN gene are known to affect the racing ability and stamina of thoroughbreds. In this study, we compared the frequency of mutations in the MSTN gene in several horse breeds, including 1,433 Jeju horses. Among the mutations (ECA18 g.66493737C>T) in the MSTN gene, the long-distance aptitude genotype (TT) was found to have a frequency of 0.826 in Jeju horses, which was higher than that in Halla horses (0.285) and thoroughbreds (0.252). The genotypes and arrival records of Jeju horses were compared according to various distances (400 m, 800 m, 900 m, 1,000 m, 1,110 m, and 1,200 m). According to the results, the CT type showed a faster-reaching record than the TT type in races of less than 1,000 m. However, almost identical results were confirmed in races over 1,110 m. This study suggests that the MSTN mutation in Jeju horses may be related to race distance aptitude. In future research, the data in this study can be used for developing markers related to race distance aptitude and racing abilities in Jeju horses.