• Korean Journal of Plant Resources
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• v.27 no.3
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• pp.256-262
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• 2014

Viscum album var. coloratum (mistletoe) is considered as one of the endangered plant species in Korea. Our objective is to restore its population and multiplication of plant by ex situ method. In this research we explored the maximum germination (in vitro) of freshly harvested and stored seeds of mistletoe collected in different time intervals. Ex vitro germination after artificial inoculation on the branches of Prunus mume in different physiological conditions was also monitored. The research revealed that the lately harvested seeds (Feb. and March 2014) were superior over early harvested seeds (Nov. 2013 and Jan. 2014) of mistletoe due to the higher percentage of germination (above 93%). According to the data, it is also revealed that the survival and germination rate of mistletoe seeds decreased with the increase in storage duration. In ex vitro germination, the fluctuated temperature of a glass house in natural condition enhanced (four fold) the rate of germination on the branches of Prunus mume than the constant temperature condition in the glass house.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.871-877
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• 2010

This study was conducted to investigate the effects of host tree species, temperature and humidity on ex vitro for seed germination in endangered species of Loranthus tanakae. In addition, we compared seed shapes between Loranthus tanakae and Viscum album that we could have easily shown in ex vitro condition. Seeds were germinated after one week inoculation and followed to develop radicles. Seed germination rates of Loranthus tanakae were 80~95% in most of the experimental conditions. The highest rate of holdfast penetrated to host plants was 72% in Populus alba var. pyramidalis among 13 different species tested at $20^{\circ}C$. Also the rates of their penetration were 57% in Morus bombycis, 55% in Acer palmatum and 42% in Castanea crenata at $20^{\circ}C$. Seeds were germinated under condition without irrigation and followed to withered in 12 weeks later. Stages of seed germination of the Loranthus tanakae were followed by radicle induction, holdfast development, haustorium formation and penetration in order in total period of 14 weeks.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.624-630
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• 2004

Functionality changes by germination of giant embryonic rice and pigmented rice were evaluated with focusing on antioxidative activities of 70% ethanolic extracts. Overall, reducing power of giant embryonic rice and pigmented rice was higher than that of normal brown rice, and the germination of rices tend to enhance their reducing powers. In vitro and ex vivo experiments employing linoleic acid peroxidation and rabbit erythrocyte membrane peroxidation systems, respectively, revealed inhibitory effect on lipid peroxidation was highest in pigmented rice, followed by giant embryonic rice, and normal brown rice from high to low order. Superoxide radical-scavenging activity decreased in order of pigmented rice > giant embryonic rice > normal brown rice, and germination also enhanced their superoxide scavenging ability compared to non-germinated controls. Hydroxyl radical-scavenging ability was highest in pigmented rice, followed by giant embryonic rice, and normal brown rice. Despite marked enhancement in hydroxyl radical-scavenging ability of normal brown rice by germination, order of scavenging ability was not altered among germinated rices. Same trend as with in vitro ROS scavenging was observed for ex vivo scavenging potency on ROSs generated by TPA stimulation in HL-60 cells. Germination-associated differential increase in ROS scavenging ability of pigmented rice and giant embryonic rice, characterized by no induction of cytotoxicity, was observed.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.239-244
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• 2015

Calanthe striata f. sieboldii Decne. ex Regel is a terrestrial orchid with beautiful flowers arranged in racemose inflorescences. This species is threatened due to over-collection and loss of suitable habitats. Asymbiotic germination is useful in the conservation efforts to re-establish plants in the wild, and for commercial propagation. In this study, we investigate the effects of sodium hypochlorite (NaOCl), three types of culture media (Phytomax Orchid Maintenance - POM, Seed Germination Maintenance - SGM, and Murashige and Skoog 1962 - MS), and plant growth regulators on embryo swelling, protocorm formation, and embryo diameter of C. striata f. sieboldii. Treatment with 1% NaOCl for 30 min greatly enhanced embryo swelling (28.3%), embryo diameter ($205.8{\mu}m$), and embryo protocorm formation (54.8%) compared to seeds without NaOCl treatment (embryo swelling 8.5%, embryo diameter $14.6{\mu}m$, and protocorm formation 13.4%) on POM medium. Protocorm formation on POM medium supplemented with 1.0 mg/L N6-benzyladenine (BA) (95.6%) was better than the control (54.5%). Additionally, the effects of activated charcoal (AC) and sucrose on seedling growth in in vitro culture were examined. The protocorm converted into healthy plants with well-developed shoot primordia on the POM medium with AC and sucrose. The most suitable conditions for seedling growth after 10 weeks of culture were the POM medium with AC or sucrose. These results show effective asymbiotic seed germination and in vitro seedling growth of C. striata f. sieboldii.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.110-118
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• 2016

We compared germination efficiency for somatic embryos (SE) of Liriodendron tulipifera using semi-solid (SS), temporary immersion bioreactors (TIB), and continuous immersion bioreactors (CIB) to produce vigorous plants. The bioreactors were designed to be immersed in liquid media with plantlets with an adjustable immersion time. TIB and CIB improved germination rates up to 80.86% and 95.21%, respectively, however, CIB produced more hyperhydric plantlets than TIB. The height of plantlets in TIB was significantly higher than for those in CIB. Fresh weights of plantlets grown in CIB of were significantly lower than for those grown in TIB. The lowest chlorophyll concentration was found in in vitro plantlets from CIB. We examined abnormally developed leaves, stems, and apical zones of in vitro plantlets that were produced in CIB. Among the three types, SS showed the highest stomatal density and the shortest stomatal length in in vitro plantlets. After acclimatization, plants from CIB exhibited the lowest values in biomass, such as height, root collar diameter, leaf fresh weight, leaf length, leaf width, petiole length, petiole diameter, and leaf area. Photosynthesis and transpiration rates of ex vitro plants were not significantly different among the three culture types, but stomatal conductance was higher in TIB than in the SS and CIB. Therefore, the results suggest that TIB is the preferable bioreactor to improve in vitro plantlet regeneration of L. tulipifera. TIB-originated plants showed higher growth rate than SS and CIB after transferring to soil.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.158-162
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• 2012

The acclimatization of in vitro propagated plants is an important step to produce vigorous plants for clonal forestry and in vitro micro-environment may affect the growth in ex vitro condition. To monitor in vitro environmental effects on the growth in ex vitro condition, several culture systems such semi-solid medium(SS), temporary immersion bioreactor(TIB) and continuous immersion bioreactor(CIB) culture types were tested to compare for the growth of acclimated plants of Liriodendron tulipifera. Results suggested that morphological characters, stomatal conductance, evapotranspiration and chlorophyll contents of acclimated plants were affected by the different of in vitro culture conditions. CIB type of culture was resulted to the lowest value in the biomass of acclimated plants. Net photosynthsis rate of CIB was the same level as those of SS and TIB. However, stomatal conductance, evapotranspiration and $CO_2$ partial pressure in the intercellular air space were lower than those of SS and TIB. The amounts of chlorophyll a, b and carotenoids were also lower than those of the other two culture systems. TIB, showing a little lower or higher value than SS in many growth character, is recommended rather than CIB to produce healthy yellow poplar plants in ex situ condition.

• Journal of Plant Biotechnology
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• v.47 no.4
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• pp.330-336
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• 2020

Ex-situ conservation of the ornamental and medicinal orchid, Coelogyne stricta, was performed by mass propagation using seed culture. Propagation stages were optimized using full- and half-strength solidified MS medium with different phytohormones. Maximum seed germination (88 ± 0.5% over 6 weeks of culture) was achieved on half-strength MS medium supplemented with 15% coconut water. Maximum shoot numbers were found on full-strength MS medium supplemented with 1 mg/L BAP, 2 mg/L Kinetin, and 10% coconut water, while the longest root was developed on full-strength MS medium with 1.5 mg/L IBA. A 2:1:1 combination of coco-peat, pine bark, and sphagnum moss was found to be a suitable potting mixture resulting in 80% seedling survivability. The cytotoxic activity of extracts of both wild plants and in vitro-developed protocorms was determined using an MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay on a cervical cancer cell line. The wild plant extract inhibited the growth of 41.99% of cells, showing that this extract has moderate cytotoxic activity toward cervical cancer cells.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.453-460
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• 2008

In the course of in vitro and in vivo screening for bioherbicidal agents, a hyphomycete fungus, Myrothecium sp. F0252 was selected as a candidate for the biocontrol of weeds. The isolate was identified as Myrothecium roridum Tode ex. Fries based on the morphological characteristics and 18S ribosomal DNA sequence analysis and registered as Myrothecium roridum F0252. In order to evaluate the in vitro effect of M. roridum F0252 on germination of ladino clover and white clover (Trifolium repens L.) seeds, spore solution of the fungus was employed in two concentrations, $6.5{\times}10^6$ and $2.5{\times}10^7$ spores per mL and then inoculated to the seeds. The fungal spores inhibited the seed germination, infected the seedlings, and caused an abnormal withering and inhibition of seedling growth. In addition, when the herbicidal activity of crude ethyl acetate extract from the liquid culture was assessed on a mini-plant, duck-weed (Lemna paucicostata (L.) Hegelm.), the extract showed high inhibitory effect at the level of $12.5{\mu}g$ per mL. On the other hand, in vivo herbicidal activity of M. roridum F0252 was evaluated by a whole plant spray method. M. roridum F0252 exhibited strong and broad-spectrum herbicidal activity. The herbicidal values ranged from 95-100% against 7 weeds, including Abutilon avicennae and Xanthium strumarium, and 70-80% against Digitaria sanguinalis and Sagittaria pygmaea. When the nutritional utilization (95 carbon sources) pattern of M. roridum F0252 was investigated, it varied with water activity ($a_w$) and temperature conditions, supplying good, basic information in regard to nutritional utilization for proper cultivation and formulation. Our results showed that M. roridum F0252 might be used as a potential biocontrol agent against weedy plants.

• Journal of Plant Biotechnology
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• v.47 no.1
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• pp.53-65
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• 2020

Here, we describe an efficient and rapid protocol for the micropropagation of Thymus pallidus Cosson ex Batt., a very rare medicinal and aromatic plant in Morocco. After seed germination, we tested the effect of different macronutrients, cytokinins alone or in combination with gibberellic acid (GA₃) or auxins, on T. pallidus plantlet growth. We found that Margara macronutrients (N₃₀K) had the best effect on the in vitro development of the plantlets. The addition of 0.93 μM/L 1,3-diphenylurea (DPU), 0.46 μM/L adenine (Ad), and 0.46 and 0.93 μM/L kinetin (Kin) resulted in the best shoot multiplication and elongation. In addition, the combination of 0.46 μM/L Kin, DPU, or Ad with gibberellic acid, in particular, 0.46 μM/L Ad + 0.58 μM/L GA₃ and 0.46 μM/L Kin + 1.15 μM/L GA₃, led to better bud and shoot multiplication. Moreover, the integration of the combinations of 0.46 μM/L Kin and auxins, namely 0.46 μM/L Kin + 2.85 μM/L indole-3-acetic acid (IAA), 0.46 μM/L Kin + 2.85 or 5.71 μM/L indole-3-butyric acid (IBA), and 0.46 μM/L Kin + 0.3 or 0.57 μM/L 1-naphthaleneacetic acid (NAA), in the culture medium led to better root development and optimized aerial growth. Finally, the in vitro plants from the medium containing N₃₀K + 0.46 μM/L Kin + 2.85 μM/L IAA were successfully acclimatized; these plants served as a source for repeating in vitro culture.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.461-471
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• 2016

This study was conducted to establish an in vitro propagation system for sea-milkwort (Glaux maritima L.), which is an endangered coastal plant species with high horticultural value. Two phenotypes, 'Red type (RT)' and 'Pistachio type (PT)' based on the colors of stem and flower, were obtained from a personal horticulturist in 2009 and used for this study as plant materials. The stock plants showed typical morphologies in flower, capsule, and seed appearances as previously reported. Low temperature treatment at $4^{\circ}C$ for four or more weeks after in vitro sowing maximized seed germination percentage, indicating that imbibition of seed and subsequent low temperature treatment are crucial for its germination. The in vitro seedlings had phenotypic variation, falling into 'RT' and 'PT' classes like the stock plants. Although slight differences depending on genotype and medium were recognized, the fourth or fifth nodes detached from the in vitro seedlings revealed the best multiplication efficacy when estimated on the basis of total number of nodes of newly developed axillary shoots. In addition, the nodes from 'RT' and 'PT' regenerated the most shoots on medium supplemented with $0.5mg{\cdot}L^{-1}$ BA alone and $0.5mg{\cdot}L^{-1}$ BA plus $0.5mg{\cdot}L^{-1}$ IAA, respectively. The node culture-derived plantlets were well acclimatized in a culture room ex vitro and completed the pseudo-annual life cycle coincident with that in the natural salt march habitat with the current cultivation method of applying fresh water-irrigation under an inland environment. This work represents the first report of in vitro propagation of sea-milkwort. Thus, our study will contribute to exo-habitat conservation and natural habitat restoration of this endangered species in addition to development of a horticultural product.