• 한국자원식물학회지
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• 제19권3호
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• pp.427-431
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• 2006

In vitro high-frequency plant regeneration of Muscari comosum var. plumosum through somatic embryogenesis was obtained via two developmental pathways: direct embryos and multiple shoots regenerated from embryogenic callus. Flower bud with pedicel, receptacle, petal and ovary wall, floral stalk and leaf as explants were cultured in MS medium supplemented with various plant growth regulators. Embryos formed directly from pedicel, receptacle and floral stalk. Depending on explant sources, the optimal medium was MS medium supplemented with 0.2 mg/L IBA and 0.3 mg/L BA, 3.0 mg/L IBA and 3.0 mg/L BA, and MS-free medium for pedicel, receptacle, and floral stalk, respectively. Multiple shoots regenerated from embryogenic cal]i which was initiated from petal, ovary and leaf were observed in MS medium with different concentrations and combinations of hormone. The most suitable medium for each type of explant was 3.0 mg/L IBA and 3.0 mg/L BA(petal and ovary) and 5.0 mg/L IBA and 5.0 mg/L BA (leaf) Furthermore, the combination of 0.1 mg/L 2,4-D and 1.0 mg/L BA was also good for all sources of explants not only for direct embryo formation, but also, for embryogenic callus induction.

• The Plant Pathology Journal
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• 제23권1호
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• pp.7-12
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• 2007

Perilla rust is a damaging disease in perilla cultivation in Korea. Its causal agent was identified as Coleosporium plectranthi based on descriptions of morphological characteristics of spores and spore-producing fruiting structures(in uredinial and telial stages from perilla and in aecial stage from the alternate host pine) collected in 15 locations in Korea during the disease survey from 2004 to 2006. These characteristics were yellow or orange uredinium; globose or ellipsoid urediniospore of $20.8{\mu}m{\times}18{\mu}m$ in size; verruca of $0.3mm{\times}1.2mm$; orange telium; one-celled, oblong ellipsoid teliospore of $63.1{\mu}m{\times}19.7{\mu}m$ with one-layered crusts or four-celled(when mature), internal basidium of $64.2{\mu}m{\times}19.7{\mu}m$; ellipsoid to globoid basidiospore of $20.3{\mu}m{\times}12{\mu}m$; type 2 spermogonium; yellow, broadly ellipsoid peridial cell of $35.6{\mu}m{\times}23.1{\mu}m$; and broadly ellipsoidal or subglobose aeciospore of $25.9{\mu}m{\times}18.8{\mu}m$. Phylogenetic analysis of 28S rDNA sequences revealed the closest relatedness to those of the genus Coleosporium, a monophyletic group distinguished from other rust fungi and divided into two main lineages, one of which was C. plectranthi grouped with high bootstrap value(96%). In pathogenicity test, both aeciospores and urediniospores caused rust development on perilla leaves. This is the first description of C. plectranthi causing perilla rust with the first findings of its telial stage on perilla and the first rust disease on the aecial host in Pinus densiflora. These aspects would provide basic information for the development of control measures of the disease.

• Genomics & Informatics
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• 제20권1호
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• pp.12.1-12.7
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• 2022

The two complete mitochondrial genomes (mitogenomes) of Paedocypris progenetica, the smallest fish in the world which belonged to the Cyprinidae family, were sequenced and assembled. The circular DNA molecules of mitogenomes P1-P. progenetica and S3-P. progenetica were 16,827 and 16,616 bp in length, respectively, and encoded 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and one control region. The gene arrangements of P. progenetica were identical to those of other Paedocypris species. BLAST and phylogenetic analyses revealed variations in the mitogenome sequences of two Paedocypris species from Perak and Selangor. The circular DNA molecule of P. progenetica yield a standard vertebrate gene arrangement and an overall nucleotide composition of A 33.0%, T 27.2%, C 23.5%, and G 15.5%. The overall AT content of this species was consistent with that of other species in other genera. The negative GC-skew and positive AT-skew of the control region in P. progenetica indicated rich genetic variability and AT nucleotide bias, respectively. The results of this study provide genomic variation information and enhance the understanding of the mitogenome of P. progenetica. They could later deliver highly valuable new insight into data for phylogenetic analysis and population genetics.

• Genomics & Informatics
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• 제19권2호
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• pp.19.1-19.9
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• 2021

Plant height is an important component of plant architecture and significantly affects crop breeding practices and yield. We studied DNA variations derived from F5 recombinant inbred lines (RILs) with 96.8% homozygous genotypes. Here, we report DNA variations between the normal and dwarf members of four lines harvested from a single seed parent in an F6 RIL population derived from a cross between Glycine max var. Peking and Glycine soja IT182936. Whole genome sequencing was carried out, and the DNA variations in the whole genome were compared between the normal and dwarf samples. We found a large number of DNA variations in both the dwarf and semi-dwarf lines, with one single nucleotide polymorphism (SNP) per at least 3.68 kb in the dwarf lines and 1 SNP per 11.13 kb of the whole genome. This value is 2.18 times higher than the expected DNA variation in the F6 population. A total of 186 SNPs and 241 SNPs were discovered in the coding regions of the dwarf lines 1282 and 1303, respectively, and we discovered 33 homogeneous nonsynonymous SNPs that occurred at the same loci in each set of dwarf and normal soybean. Of them, five SNPs were in the same positions between lines 1282 and 1303. Our results provide important information for improving our understanding of the genetics of soybean plant height and crop breeding. These polymorphisms could be useful genetic resources for plant breeders, geneticists, and biologists for future molecular biology and breeding projects.

• Korean Journal of Radiology
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• 제21권1호
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• pp.117-117
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• 2020

• 한국산림과학회지
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• 제17권1호
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• pp.1-15
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• 1973

돌연변이수발(突然變異誘發)에 의(依)한 방법(方法)으로 중요조림수종(重要造林樹種)의 품종(品種)을 개량(改良)코자 Robinia pseudoacacia, Pinus densiflora, Pinus rigida, Pinus thunbergii 및 Larix leptolepis의 종자(種子)를 미국(美國) Brookhaven National Laboratory에 송부(送付)하여 X-ray와 thermal neutron를 조사처리(照射處理)하고 상기종자(上記種子)들의 발아율(發芽率)을 조사(調査)하는 한편 조사처리(照射處理)된 종자(種子)에서 얻어진 아까시나무 유묘(幼苗)의 몇몇 특성(特性)을 조사(調査)하였다. 1. Thermal neutron 3시간(時間)~9시간(時間) 조사처리(照射處理) 범위(範圍)에 있어서 조사처리시간(照射處理時間)의 증가(增加)에 따라 Robinia pseudoacacia, Pinus densiflora, Pinus thunbergii 및 Pinus rigida 종자(種子)의 발아율(發芽率)이 감소(減少) 되었으며 특(特)히 Larix leptolepis의 종자(種子)는 이와 같은 선량범위내(線量範圍內)에서 완전(完全) 치사(致死)하였다. 2. X-ray 10,000r~30,000r 범위(範圍)의 조사처리(照射處理)는 Pinus densiflora, Robinia pseudoacacia, Pinus rigida 종자(種子)의 발아율(發芽率)을 대단조해(大端阻害) 저하(低下)시켰고 특(特)히 Pinus thunbergii와 Larix leptolepis의 종자(種子)는 거의 치사(致死)케하였다. 3. 조사처리(照射處理)된 아까시나무의 생장상황(生長狀況)은 X-ray 및 thermal neutron 조사처리(照射處理)에 있어 선량(線量)의 증가(增加)에 따라 모두 생육(生育)이 저하(低下)되었으나 thermal neutron으로 3시간(時間) 조사처리(照射處理)된 개체(個體)들은 비교목(比較木)에 비(比)하여 14.9% 생육증가(生育增加)를 보였으며 또한 가시없는 개체(個體)가 상당(相當)히 출현(出現)되었다. 4. 조사처리(照射處理)된 아까시나무의 형태적(形態的) 변이(變異)에 있어서는 X-ray 및 thermal neutron 조사처리(照射處理)에 있어서 엽반입개체(葉搬入個體), 엽부정형개체(葉不整形個體), 백자개체(白子個體), 등(等)이 출현(出現)되었다. 5. Thermal neutron으로 조사처리(照射處理)된 아까시나무는 정상적(正常的)인 체세포분열(體細胞分裂)이 대부분(大部分)이나 비정상적(非正常的)인 세포분열(細胞分裂), 이핵세포(二核細胞), 이인세포(二仁細胞) 및 염색체괴(染色體塊) 등(等)을 관찰(觀察)할 수 있었다. 6. X-ray 및 thermal neutron 조사처리(照射處理)된 아까시나무의 pawdery mildew에 대(對)한 저항성(抵抗性)은 선량증가(線量增加)에 따라 감소(減少)되었다. 7. Thermal neutron 조사처리(照射處理)된 아까시나무의 기공장(氣孔長)은 비교목(比較木)과 대차(大差)가 없었고 단위면적당기공수(單位面積當氣孔數)는 처리목(處理木)이 감소(減少)되었다. 또한 엽전체(葉全體)의 후(厚) 및 엽표층(葉 表層)의 후(厚)는 thermal neutron 조사처리목(照射處理木)이 비교목(比較木)에 비(比)하여 증가(增加)되었으며 붕상조직(棚狀組織)의 폭(幅)은 비교목(比較木)보다 감소(減少)되었다.

• ALGAE
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• 제35권1호
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• pp.79-89
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• 2020

Pythium species are ubiquitous organisms known to be pathogens to terrestrial plants and marine algae. While several Pythium species (hereafter, Pythium) are described as pathogens to marine red algae, little is known about the pathogenicity of Pythium on marine green algae. A strain of a Pythium was isolated from a taxonomically unresolved filamentous Ulva collected in an intertidal area of Oslo fjord. Its pathogenicity to a euryhaline Ulva intestinalis collected in the same area was subsequently tested under salinities of 0, 15, and 30 parts per thousand (ppt). The Pythium isolate readily infected U. intestinalis and decimated the filaments at 0 ppt. Mycelium survived on U. intestinalis filaments for at least 2 weeks at 15 and 30 ppt, but the infection did not progress. Sporulation was not observed in the infected algal filaments at any salinity. Conversely, Pythium sporulated on infected grass pieces at 0, 15, and 30 ppt. High salinity retarded sporulation, but did not prevent it. Our Pythium isolate produced filamentous non-inflated sporangia. The sexual stage was never observed and phylogenetic analysis using internal transcribed spacer suggest this isolate belongs to the clade B2. We conclude that the Pythium found in the Oslo fjord was a pathogen of U. intestinalis under low salinity.

• Plant Resources
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• 제7권1호
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• pp.77-86
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• 2004

The reduced ratio of red:far-red (R:FR) light acts as a measure of the proximity of competitors and plants can detect the potentially competing neighbor plants by perceiving reflected R:FR signals and initiate the response of “shade avoidance” before actual shading occurs. The phytochrome system is responsible for monitoring the changes in the R:FR and initiating the shade avoidance response. The response to low R:FR ratio was studied in a white aspen Populus alba clone ‘Bolleana’ using two filter systems: a clear plastic filter system that allows a R:FR ratio less than 1.0 to pass from adjacent border plant reflection; and a special commercial plastic that blocks FR light and creates a R:FR ratio above 3.0. The reduced R:FR signals enhanced the stem elongation in response to competition at the expense of relative stem diameter growth. Trees grown inside clear chambers were 27 ％ taller than trees grown inside the FR-blocking filter chambers. Stem taper of clear chamber trees was 16％ less than the FR-blocking filter trees. Low R:FR also induced 22％ more stem dry weight and 13％ greater petiole length per leaf compared to the FR-blocking filter trees. There were no statistically significant differences in leaf area, leaf number increment, and total dry weight between the two light filter treatments.

• Journal of the Korean Wood Science and Technology
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• 제51권3호
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• pp.222-237
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• 2023

Eucalyptus pellita is one of the fast-growing tree species and has become predominant in Indonesian forest plantations. Meanwhile, tree breeding programs with clone development are the best way to provide greater genetic advantages. A better understanding of genetic control on growth and basic density in E. pellita is important for increasing wood productivity and quality. In this study, growth characteristics (tree height, diameter, and volume), basic density and its genetic parameters (heritability, genetic gain and genetic correlation) were determined. The number of clones tested in both trials was 50, divided into 5 blocks, and 5 trees/plot. The results showed that there were significant differences in growth and basic density among clones. There was an interaction between genetics and the environment further indicating the existence of unstable clones. The high heritability was found in tree height (0.82-0.86), diameter (0.82-0.90), and basic density (0.91-0.93). This implies that E. pellita has good opportunities for genetic improvement to increase wood productivity and quality. In addition, the results of genetic correlations among growth characteristics (height, diameter, and volume) and basic density showed positive moderate to highly significant value. It is suggested that these characters may be used to the advantage of the breeder for bringing improvement in these traits simultaneously. Therefore, this study provides important information of the genetic improvement of wood quality in E. pellita in Indonesia.

• 한국산림과학회지
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• 제45권1호
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• pp.51-61
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• 1979

교배(交配) 모수(母樹)인 P. alba화분(花粉) 모수(母樹)인 P. glandulosa 및 그의 잡종(雜種)인 ${\times}$P. albaglandulosa에 관(關)한 화분모세포(花粉母細胞)의 감수분열(減數分裂)에 있어 염색체행동(染色体行動)과 대합(對合) 현상(現象)에 관(關)해 조사(調査)하였다. 1. Metaphase II에서 Earyl separation chromosome을 갖는 핵판(核板)이 가장 적은 개체(個体)는 P. glandulosa로 11.0%며 ${\times}$P. albaglandulosa는 13.0%로 가장 높았다. 2. Metaph se II에서 ${\times}$P. albaglandulosa는 11.0%의 Early separation chromosome이 출현(出現)했으나 양친양친수(兩親兩親樹)와 차이(差異)는 없었다. 3. Anahase I에서 Lagging chromosome의 출현율(出現律)은 ${\times}$P. albaglandulosa가 다소(多少) 높아 11.6%로 나타났으며 chromosome bridge에서는 양친수(兩親樹)와 거의 차(差)가 없었다. 4. Anaphase II때 Lagging chromososome은 ${\times}$P. albaglandulosa에서 다소(多少) 높은 빈도(頻度)로 10.2%였으며 chromosome bridge P. glandulosa에서 가장 높은 빈도(頻度)로 출현(出現)하였다. 5. Abnormal pollen sporad는 ${\times}$P. albaglandulosa에서 가장 많이 출현(出現)하여 8.2%를 나타냈다. 이상(以上)의 결과(結果) P. alba, P. glandulosa 및 ${\times}$P. albaglandulosa는 화분모세포분열(花粉母細胞分裂)에 있어서 염색체분열접합(染色体分裂接合)이 정상적(正常的) 행동(行動)을 하고 있어 결국(結局) 정상(正常) 화분형식(花粉形式)을 행(行)하는 수종(樹種)이라 결론(結論)할 수 있다.