• 한국약용작물학회지
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• 제10권4호
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• pp.263-268
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• 2002

Acifluorfen-tolerant callus lines of Solanum ptycanthum were isolated by stepwise selection. Growth of the unselected line was completely inhibited at 0.5 uM. while some selected lines grew at 8 uM acifluorfen. Twenty-two of twenty-five acifluorfen-tolerant callus lines regenerated shoots. Many of the regenerated somaclones were variants, differing in leaf shape, leaf color, number of flower parts, flower color, and fertility. The acifluorfen tolerant S. ptycanthum callus lines differed.

• Journal of Plant Biotechnology
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• 제49권3호
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• pp.187-192
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• 2022

식물 캘러스의 월간 또는 주간의 반복적인 계대배양은 노동 집약적이며 모 세포주로부터 somaclonal variation 발생 위험을 증가시킨다. 식물 캘러스를 보존하기위한 가장 효과적인 방법은 액체질소에 저장하는 초저온동결보존 방법이다. 하지만 초저온동결보존 방법은 동일한 방법으로 여러 식물의 캘러스에 적용할 수 없어 보존 방법 개발에 많은 어려움이 따른다. 또한 해동 후 냉동되어진 캘러스의 생존과 생존 후 재생 속도가 불확실 하다는 단점이 있다. 그러므로 활성 상태의 식물 캘러스의 계대배양 간격을 증가시키는 방법의 개발이 필요하다. 본 연구에서는 냉동과정 없는 활성상태의 다양한 종의 식물 캘러스를 계대배양 없이 4주에서 12주 동안 15℃에서 배양하였다. 25℃에서 12주간 배양한 8종류의 식물 캘러스들은 모두 2배 이하의 성장을 보였으나 15℃에서 12주간 배양 조건에서는 8종류의 식물 캘러스들은 최소 2배 이상의 성장을 하였다. 또한 15℃에서 배양 후 25℃에서 회복시킨 캘러스들 사이의 항산화 활성 역시 크게 변화하지 변하지 않았다. 이러한 결과는 배지조성이나 특별한 새로운 과정없이 15℃ 저온으로 계대배양 간격을 증가시킬 수 있음을 보여준다. 또한 여러 식물 종의 캘러스들 모두에서 긍정적인 결과는 여러 캘러스들에 동일한 방법으로 계대배양 간격을 증가시킴으로 노동력 감소는 물론 somaclonal variation을 상대적으로 줄여 줄 것으로 예상한다.

• Plant Biotechnology Reports
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• 제5권2호
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• pp.187-195
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• 2011

The gesneriaceous perennial plant Titanotrichum oldhamii has beautiful foliage and attractive bright yellow flowers. However, breeding of T. oldhamii by conventional sexual hybridization may be difficult because sexual reproduction of this species is very rare. In the present study, plant regeneration systems via both direct and indirect formation of adventitious shoots from leaf explants were established as the first step toward breeding T. oldhamii by using biotechnological techniques. Adventitious shoots were formed efficiently on medium containing $0.1mg\;l^{-1}$ benzyladenine. Histological observation showed that shoot formation on this medium occurred directly from leaf epidermal cells without callus formation. On the other hand, leaf explants formed calluses on medium containing $0.1mg\;l^{-1}$ 2,4-dichlorophenoxyacetic acid. The calluses could be maintained by monthly subculturing to fresh medium of the same composition. When the calluses were transferred to plant growth regulator-free medium, they formed adventitious shoots. Directly and indirectly formed shoots rooted well on medium containing $0.1mg\;l^{-1}$ indole-3-butyric acid. Plantlets thus obtained were successfully acclimatized and grew vigorously in the greenhouse. Flow cytometry analysis indicated that no variation in the ploidy level was observed in plants regenerated via direct shoot formation, whereas chromosome doubling occurred in several plants regenerated via indirect shoot formation. Regenerated plants with the same ploidy level as the mother plants showed almost the same phenotype as the mother plants, whereas chromosome-doubled plants showed apparent morphological alterations: they had small and crispate flowers, and round and deep green leaves.

• 한국작물학회지
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• 제49권1호
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• pp.69-72
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• 2004

Somaclonal variation, defined as phenotypic and genetic variations among regenerated plants from a parental plant, could be caused by changes in chromosome structure, single gene mutation, cytoplasm genetic mutation, insertion of transposable elements, and DNA methylation during plant regeneration. The objective of this study was to evaluate DNA variations among somaclonal variants from the cotyledonary node culture in soybean. A total of 61 soybean somaclones including seven $\textrm{R}_1$ lines and seven $\textrm{R}_2$ lines from Iksannamulkong as well as 27 $\textrm{R}_1$ lines and 20 $\textrm{R}_2$ lines from Jinju 1 were regenerated by organogenesis from the soybean cotyledonary node culture system. Field evaluation revealed no phenotypic difference in major agronomic traits between somaclonal variants and their wild types. AFLP and SSR analyses were performed to detect variations at the DNA level among somaclonal variants of two varieties. Based on AFLP analysis using 36 primer sets, 17 of 892 bands were polymorphic between Iksannamulkong and its somaclonal variants and 11 of 887 bands were polymorphic between Jinju 1 and its somaclonal variants, indicating the presence of DNA sequence change during plant regeneration. Using 36 SSR markers, two polymorphic SSR markers were detected between Iksannamulkong and its somaclonal variants. Sequence comparison amplified with the primers flanking Satt545 showed four additional stretches of ATT repeat in the variant. This suggests that variation at the DNA level between somaclonal variants and their wild types could provide basis for inducing mutation via plant regeneration and broadening crop genetic diversity.

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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• pp.94-101
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• 2004

The gross composition, gross amino acid content, apparent ileal amino acid digestibility and apparent ileal digestible amino acid content from 64 commercially produced meat and bone meals were statistically analysed. The samples were produced by 22 plants over a 2.5 year period with eight plants using batch dry rendering and 14 plants using low temperature rendering. A linear model with method and time of year (period) as fixed effects, plant within method as a random effect and sheep percent as a covariate was fitted to the composition data. The majority of the variation in the gross composition, amino acid digestibility and digestible amino acid content was explained by differences between plants using the same method. Neither rendering season nor origin of the raw materials contributed significantly to the observed variation in meat and bone meal protein quality. Rendering method (low temperature or batch rendering) had a significant effect on the variation observed in gross fat content, gross energy content, pepsin nitrogen digestibility, protein solubility and total lanthionine content. The digestibility of a number of amino acids and the apparent digestible content of arginine, cysteine, aspartic acid, proline and hydroxyproline were also significantly affected by rendering method. On average, batch dry and low temperature rendering systems produce meat and bone meals of similar nutritional quality. The variation between plant and within plant, however, is large, indicating that purchasing meat and bone meal from the same plant does not guarantee a consistent quality.

• 한국수자원학회논문집
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• 제43권4호
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• pp.393-398
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• 2010

하천의 유입량 변화와 이로 인한 소수력발전소의 수문학적 성능변화에 대한 연구가 수행되었다. 하천에서의 유입량변화를 분석하기 위하여 유량지속특성을 예측할 수 있는 모델이 개발되었고, 이를 기반으로 하여 소수력발전소의 수문학적 성능특성을 예측할 수 있는 모델이 개발되었다. 개발된 모델의 효용성을 확인하기 위하여 안동댐에서 32년간 측정된 월유입량자료를 분석하였으며, 안동댐 상류에 위치한 소수력발전소를 대상으로 하여 수문학적 성능특성을 분석하였다. 안동댐에서의 장기유입량과 기존의 소수력발전소를 대상으로 분석한 결과, 본 연구에서 개발된 예측모델로부터 획득한 결과가 실측자료와 잘 일치하였다. 최근 유입량증가로 인하여 소수력가용량을 증가하였으나 기존의 소수력발전소의 가동률을 증가시키지는 못한 것으로 나타났다. 본 연구에서 개발된 모델은 소수력발전소의 초기설계제원과 유입량을 예측하는데 유용하게 사용될 수 있다는 것이 밝혀졌다.

• The Plant Pathology Journal
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• 제25권4호
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• pp.303-316
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• 2009

Genetic variation among the base isolates and monosporidial strains derived from these isolates of Tilletia indica- the causal agent of Karnal bunt (KB) in wheat, was analyzed by morphological, growth behaviors and RAPD-ISSR based molecular polymorphism. Genetic make up of fungal cultures vary among each other. The magnitude of variation in KBPN group is less (narrow genetic base) when compared to the other groups KB3, KB9 and JK (broad genetic base) reflecting that variability is a genetically governed process. The generation of new variation with different growth characteristics is not a generalized feature and is totally dependant on the original genetic make-up of the base isolate generating new monosporidial strains. Thus, it can be concluded that monosporidial strains derived from mono-teliosporic isolate, consists of genetically heterogeneous population. The morphological and genetic variability further suggests that the variation in T. indica strains is predominantly derived through the genetic rearrangements through para sexual means.

• ALGAE
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• 제33권1호
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• pp.49-54
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• 2018

Red algal mitochondrial genomes (mtDNAs) can provide useful information on species identification. mtDNAs of Pyropia / Porphyra (Bangiales, Rhodophyta) have shown diverse variation in their size and gene structure. In particular, the introns and intronic open reading frames found in the ribosomal RNA large subunit gene (rnl) and cytochrome c oxidase subunit 1 gene (cox1) significantly vary the mitochondrial genome size in Pyropia / Porphyra species. In this study, we examined the exon / intron structure of rnl and cox1 genes of Pyropia yezoensis at the intraspecific level. The combined data of rnl and cox1 genes exhibited 12 genotypes for 40 P. yezoensis strains, based on the existence of introns. These genotypes were more effective to identify P. yezoensis strains in comparison to the traditional DNA barcode cox1 marker (5 haplotypes). Therefore, the variation in gene structure of rnl and cox1 can be a novel molecular marker to discriminate the strains of Pyropia species.

• 한국수산과학회지
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• 제47권5호
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• pp.645-653
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• 2014

We examined seasonal variation in fish species composition in coastal waters near Wolseong Nuclear Power Plant in the East Sea of Korea. A total of 72 species, 39 families, 14 orders, 46,214 individuals, and 4,639,667 g were collected. Glyptocephalus stelleri was the most dominant species by number of individuals (35%), followed by Clupea pallasii (26%). Liparis tanakai and Lophius litulon were the dominant species by biomass, accounting for 46% and 28%, respectively. We showed that bottom salinity and temperature are the most important environmental factors influencing fish species composition. Although bottom salinity did not differ statistically among seasons or stations, we detected some variation among stations. Additionally, bottom temperature differed among seasons and stations (P<0.05), affecting numbers of individuals and biomass. Thus, seasonal variation in fish assemblages can be classified into two groups: spring/summer and autumn/winter.

• 한국자원식물학회지
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• 제36권3호
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• pp.237-255
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• 2023

Variations in phenotypic traits are important for onion genetic improvement. The aim of this study was to identify the phenotypic traits of temporary genetic resources and the best accessions for the development of onion breeding programs. Sixteen phenotypic traits of 79 onion accessions were studied. The descriptive statistics of phenotypic traits exhibited a high variation in onion accessions. Among the 79 evaluated accessions, 64.55% had a large bulb neck width and 44.30% had a circular bulb shape. Principal component analysis showed that six principal components (PCs) accounted for 72.65% of the total variation. The main factors contributing to PC1 were bulb weight, equatorial and bulb polar diameters, plant height, and degree of splitting into bulblets, whereas those contributing to PC2 were the bulb color of the epidermal cells of the fleshy scales and color of the dry skin on the bulb. The accessions were classified into three groups-clusters 1, 2, and 3. Cluster 2 accessions were the most suitable for selecting large and circular bulb-shaped onion cultivars. The phenotypic variation observed in this study may help to select potential accessions for breeding new onion cultivars.