• 원예과학기술지
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• 제32권3호
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• pp.382-389
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• 2014

Raphanus sativus L. cv. Taebaek, a efficiently microspore-derived embryo (MDE)-forming cultivar, and 'Chungwoon', a non-MDE-forming cultivar were selected as donor plants for isolated microspore culture. Radish flower bud of 2.0 (small, S), 4.0 (medium, M), and 6.0 (large, L) ${\pm}$ 0.5 mm in length were isolated to determine the temporal relationship between flower bud size and MED yield. Anatomical observations revealed no difference in the structure of the flower buds between the two cultivars. In both cultivars, the stigmas were much longer than the floral leaf in M-sized flower buds. The MDE yields for 'Taebaek' per petri dish were 6.6 and 1.3 for M- and L-sized of flower buds, respectively, but MDE formation was not induced in the S flower buds. On the other hand, 'Chungwoon' failed to form MDEs in all flower buds. The microspore density of 'Taebaek' was 1.3 times more than that of 'Chungwoon' for M sized flower buds. Of the M-sized buds from 'Taebaek' and 'Chungwoon', 92.1 and 81.6%, respectively, were in the late uninucleate microspore stage, which is characterized by the highest frequency of MDE formation. Anatomical observations of MDE formation revealed that the microspores were able to divide to form a primordium from which cell division took place continuously in the 'Teabeak' cultivar. However, the microspores of 'Chungwoon' failed to progress beyond the primodium stage, resulting in lack of MDE formation. By contrast, after the formation of the primordium, various developmental stages of embyos from microspore were observed in the 'Taebaek' cultivar. These results can be used to determine MDE forming potentials of radish cultivars.

• 원예과학기술지
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• 제33권3호
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• pp.356-363
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• 2015

This study examined the effects of different day/night temperature regimes or silver ion on growth and flowering of passion fruit 'Tai-nung No.1'. Low temperature treatment ($20/15^{\circ}C$) caused passion fruit cultivar 'Tai-nung No.1' to fail to flower. Flowering induction occurred within a temperature range of $20-30^{\circ}C$, with no significant difference in the days to first flower bud and the total number of flower buds between plants grown at $30/25^{\circ}C$ and $25/20^{\circ}C$. However, plants grown at $30/25^{\circ}C$ exhibited their first flower buds set on the higher nodes and had higher abortion rates of flower buds than those at $25/20^{\circ}C$. Plants grown at $30/25^{\circ}C$ had the most rapid growth and the shortest plastochron. We also evaluated the effect of the ethylene response inhibitors silver nitrate ($AgNO_3$) and silver thiosulfate (STS) on growth and flowering of potted passion fruit 'Tai-nung No.1', when they were exposed to low temperature conditions ($20/15^{\circ}C$) following chemical treatments ($AgNO_3$ or STS, at 0.5 or 1.0 mM). $AgNO_3$ and STS treatments induced flower formation and initial flower bud formation within approximately two weeks at $20/15^{\circ}C$ whereas non-treated control plants exhibited no flower formation. ACC content and activity of ACC oxidase in the leaves of passion fruit 'Tai-nung No.1'exposed to low temperature conditions ($20/15^{\circ}C$) were significantly inhibited by the ethylene inhibitor treatments. These results indicate that ethylene, which is produced under low temperature conditions, plays an important role in inhibiting flower formation in passion fruit.

• 농업과학연구
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• 제47권4호
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• pp.987-993
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• 2020

This study investigated the effective harvest of 'Kyoho' grapevines by examining their characteristics including bud development, necrosis types and flower primordium formation. The size of the axillary bud did not show any difference in the 5th node or more, but it was smaller because it was closer to the base in the 4th node or less. In the 1st node, the rates of main bud necrosis (MBN), accessory bud necrosis (ABN), and whole bud necrosis (WBN) were high, and the rate of flower primordium formation was low, but there was no significant difference in the other nodes. Therefore, it was expected that using other nodes than the 1st node would be advantageous to secure production. Because the growth progresses after sprouting, the main bud necrosis rate increases, showing a very low flower primordium formation rate in March of the following year. Therefore, a method is needed to increase the storage nutrients in the winter and the rate of flower primordium formation after March. This study found that the thickness of the shoots should be less than 8.5 mm between the 3rd and 4th nodes, and the length should be less than 60 cm for nodes up to the 10th node.

• 한국지구과학회지
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• 제34권5호
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• pp.402-406
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• 2013

Since 1984, the author has been studying the Daedong flora and has collected a large number of fossil plants from the Amisan Formation of Nampo Group distributed in Chungnam Coal-Field. One of the fossil plants was bennettitalean male flower, which was collected in 1986. The author described it as Weltrichia sp. The occurrence of Weltrichia sp. is the first record in the Early Mesozoic Daedong flora of Korea.

• 한국자원식물학회지
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• 제1권1호
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• pp.48-52
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• 1988

식물생장촉진제와 억제제의 처리가 동백의 화아형성과 개화기에 미치는 영향을 알아본 결과 다음과 같은 결과를 얻었다. 1. 봄철 맹어후 살포처리한 gibberellin은 shoot의 신장을 촉진시켰으나 화아형성을 억제시켰다. 2. Cycocel(CCC)의 처리는 화아형성에 촉진적으로 작용하였다. 3. 화아에 처리한 gibberellin은 개화시기를 효과적으로 단축시켰다.

• 화훼연구
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• 제17권3호
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• pp.165-171
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• 2009

팔레높시스 화경의 모든 부위를 사용한 화경절편조직을 기내 배양하여 효율적이고 변이 발생률이 낮은 균일한 식물체를 일시에 대량생산하기 위하여 Hyponex와 생장조절물질 TDZ, BA의 적정 농도를 규명하고자 하였다. 두 공시 품종은 Hyponex, TDZ, BA 농도별로 floral stem, shoot, 다신초의 기관형성 발생에서 차이를 보였다. 팔레높시스의 화경절편조직 배양에 적절한 Hyponex의 농도는 $4g{\cdot}L^{-1}$ 가 가장 효과적이었으며, 다신초 형성에 효과적인 TDZ의 농도는 $0.3mg{\cdot}L^{-1}$이고, BA의 농도는 $5mg{\cdot}L^{-1}$ 이었다. 화경절편조직 배양 시 Hyponex $4g{\cdot}L^{-1}$을 기본배지로 하여 TDZ와 BA의 효과를 비교한 결과 TDZ가 더 효과적이었다.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1996년도 제10회 식물생명공학심포지움 고등식물 발생생물학의 최근 진보
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• pp.10-18
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• 1996

Recently, we have reported a rice MADS-box gene, OsMADS1, as a molecular factor triggering flower formation; this has been well studied in a heterologous system (Chung et al., 1994). In order to study whether the OsMADS1 homolog exists in other plant species, the OsMADS1 cDNA was used as a probe to screen a tobacco cDNA library, and a potential homolog, NtMADS3, was isolated. Sequence analysis revealed that the gene shares 56.1% identity in whole amino acids with OsMADS1. Like OsMADS1, the NtMADS3 gene starts to express at a very early stage of flower development, and the expression continues up to flower maturation. In the tobacco flower, the gene is expressed in whorl 2,3 and 4, corresponding to the petal, stamen, and carpel, respectively. Upon ectopic expression in the homologous system, NtMADS3 caused a trasition from inflorescence shoot meristem into floral meristem, reducing flowering time dramatically. These phenotypes strongly suggest the NtMADS3 gene is the OsMADS1 homolog of tobacco. Hybrids between the OsMADS1 and the NtMADS3 plants were also generated. The hybrids flowered even earlier than these two transgenic plants. The detailed studies are discussed here.

• Journal of Ecology and Environment
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• 제46권3호
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• pp.243-249
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• 2022

Background: Mixed breeding herb Viola collina Besser, which produces both chasmogamous and cleistogamous flower, has limited habitats under closed canopy and short and early flowering timing, making it relatively more vulnerable to climate change. To better understand the effect of light and nutrient on the flower formation and vegetative growth of V. collina, a mesocosm experiment was conducted. Two-by-two factorial treatments of two light conditions (100% and 60% of natural light) and two fertilizer treatment conditions (fertilized and not fertilized) were applied in the mesocosm experiment. Results: The number of flowers, including chamogamous and cleistogamous flowers, was highest (5.65/pot) under 60% light and fertilized condition and lowest (1.41/pot) under 100% light and not-fertilized condition. However, above ground vegetative growth was highest (2.89 g/pot) under 100% light and fertilized condition and lowest (2.38 g/pot) under 60% light and not-fertilized condition. Above ground biomass to belowground biomass ratio was highest (1.50) under 60% light and fertilized condition and lowest (1.26) under 100% light and fertilized condition. Conclusions: This study showed that high light and nutrient are responsible for the vegetative growth, though the effect of fertilizer was reduced due to allocation and retainment of nutrients. In addition, the low light is necessary to make flowers, especially chasmogamous flowers.

• 생명과학회지
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• 제27권9호
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• pp.1059-1063
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• 2017

혈관신생과정은 종양 형성과 이동에 필수적인 과정으로 촉진제와 저해제에 의하여 조절되며, 이러한 혈관신생과정의 저해는 새로운 항암치료 기법으로 이용하고 있다. 최근, 한약재와 식료품으로부터 추출한 천연물을 새로운 치료 물질로 널리 이용하고 있으며, 실제 in vitro 뿐만 아니라 in vivo 상에서도 항암 효과가 나타나는 것을 확인하였다. 그 중 도라지는 아시아에서 한약재와 식료품으로 오랫동안 사용 되어왔다. 본 연구에서는 도라지 추출물이 in vitro 상에서 인간 제대 정맥 내피 세포의 혈관신생을 억제하는 효과에 대해 조사하였다. 도라지 추출물은 세포독성 없이, 혈관 형성 및 이동, 침윤 현상을 모두 억제하는 효과를 보였다. 특히, 세포 이동은 80% 정도 감소 시켰으며 침윤 현상이 거의 나타나지 않는 것을 확인하였다. 이러한 결과를 토대로 도라지 추출물은 혈관신생 억제제로 이용할 수 있으며, 더 나아가 항암제로 개발될 수 있을 것이라 사료된다.

• Journal of Ginseng Research
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• 제8권1호
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• pp.45-56
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• 1984

This study was carried out to obtain the basic information on the development of flower bud and to clarify the characteristics of flower organ and flowering in Korean ginseng (Panax ginseng) and American ginseng (Panax quinquefolium). The formation of flower bud in the dormancy bud of Korean ginseng was initiated about the middle of June and completed late in September. The ovary, style and anther of Panax ginseng, violet-stem and yellow-berry variants, were formed earlier than those of Panax quinquefolium. Panax ginseng, therefore, flowered earlier by one month in comparison with Panax quinquefolium. As for the effect of temperature on the flowering of ginseng, both species, Panax ginseng and Panax quinquefolium, grown at 20 $^{\circ}C$ flowered earlier than those at 15 $^{\circ}C$ and field conditions, but did not flower at 30 $^{\circ}C$. Seed characters were better in Panax ginseng than in Panax quinquefolium and the amount of seeds showed the highly significant positive correlation coefficient with peduncle length in both Panax ginseng and Panax quinquefolium.