• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.235-240
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• 2007

Optimum tissue culture conditions for an efficient induction of embryogenic callus from mature seeds of perennial ryegrass (Lolium perenne L.) and regeneration of plants from callus tissues were investigated. MS medium containing 3 mg/L 2,4-D and 0.1 mg/L BA was optimal for embryogenic callus induction from mature seeds. The highest plant regeneration frequency (58.3%) was observed when the embryogenic callus tissues were cultured on N6 medium supplemented with 1 mg/L 2,4-D and 3 mg/L BA. Regenerated plants were grown normally when shoots transplanted to the soil. A short tissue culture period and high-frequency regeneration system would be helpful for molecular breeding of perennial ryegrass through Agrobacterium-mediated genetic transformation.

• Molecules and Cells
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• v.39 no.10
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• pp.768-775
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• 2016

The Arabidopsis female gametophyte contains seven cells with eight haploid nuclei buried within layers of sporophytic tissue. Following double fertilization, the egg and central cells of the gametophyte develop into the embryo and endosperm of the seed, respectively. The epigenetic status of the central cell has long presented an enigma due both to its inaccessibility, and the fascinating epigenome of the endosperm, thought to have been inherited from the central cell following activity of the DEMETER demethylase enzyme, prior to fertilization. Here, we present for the first time, a method to isolate pure populations of Arabidopsis central cell nuclei. Utilizing a protocol designed to isolate leaf mesophyll protoplasts, we systematically optimized each step in order to efficiently separate central cells from the female gametophyte. We use initial manual pistil dissection followed by the derivation of central cell protoplasts, during which process the central cell emerges from the micropylar pole of the embryo sac. Then, we use a modified version of the Isolation of Nuclei TAgged in specific Cell Types (INTACT) protocol to purify central cell nuclei, resulting in a purity of 75-90% and a yield sufficient to undertake downstream molecular analyses. We find that the process is highly dependent on the health of the original plant tissue used, and the efficiency of protoplasting solution infiltration into the gametophyte. By isolating pure central cell populations, we have enabled elucidation of the physiology of this rare cell type, which in the future will provide novel insights into Arabidopsis reproduction.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.301-304
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• 1998

Effects of genotype and culture medium on plant regeneration from cotyledon segments of red pepper(Capsicum annuum L.) was investigated. Among combinations of IAA(0.25 and 0.50 mg/L) and zeatin(2.0 and 4.0 mg/L) added to MS medium, combination of 2.0 mg/L zeatin and 0.25 mg/L IAA was shown to be the best for shoot differentiation from cotyledon segments. Shoot regeneration from cotyledon explants took 9 to 25days, depending on genotypes and culture media. Early shooting was observed in Yeongyangjaelae, Putgochw, Karkovskij-A-35, Gris I-A-1 on MS medium containing 2.0 mg/L zeatin and 0.25 IAA mg/L. Percent of explants producing shoots, as also influenced by genotypes and culture media, were over 90% for 621, Yeongyangjaelae, Putgochw, Nikko jacksacgmulgochw, Ch-6-Num-216, and Kajenskij-A-35 when cultured on MS medum supplemented with 2.0 mg/L zeatin and 0.25 mg/L IAA and for Fresno chile, PI 169126, Kajenskij-A-35, jacksacgmulgochw, and PI 297438 on MS medium including 2.0 mg/L BA and 1.0 mg/L IAA.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.183-187
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• 1998

Chlorophyll mutants were produced by treating the rhizome of Cymbidium kanran with mutagen, EMS(ethyl methan sulfonate). The germination ratio of Cymbidium kanran seeds was 5.5 times higher when the seeds were treated with ultrasonic treatment for 20 minutes than untreated control. Fifty to sixty percent of the rhizomes became dark brown when they were cultured in a liquid growth medium containing 0.2% EMS for three weeks. When the dark-brown rhizomes were cultured in a solified MS medium, new rhizomes were developed from a part of the old ones. Chlorophyll mutant rhizomes were obtained from a meristem tissue by a subculturing the cuts of these new rhizomes for a year. Of the chlorophyll mutants, a zigzag-striped type of rhizome was dominant and light-yellow and albino ones were also produced. While the zigzag-striped type rhizomes were differentiated into green and striped plant, the light yellow and the white rhizomes produced yellow-striped and albino plants repectively.These results indicate that the EMS treatment on the rhizome is an effective means to induce a chlorophyll mutant. We believe that this method may be useful to produce variegated plants chlorophyll mutants from other orchids.

• The Plant Pathology Journal
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• v.28 no.2
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• pp.191-196
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• 2012

Periwinkle seedlings (Cantharanthus roseus) were inoculated with jujube witches'- broom (JWB) phytoplasma via grafting to analyze the migration of JWB phytoplasmas within the host plant. The phytoplasmas were detected using nested polymerase chain reaction (PCR) and fluorescence microscopy. Fluorescence microscopy was a simple and easy method of detecting phytoplasmas; however, it was not sufficiently sensitive to detect very low phytoplasma concentrations. Therefore, the migration of JWB phytoplasma was investigated through PCR. The first migration of JWB phytoplasma from an infected tissue to healthy tissues occurred late. After grafting, the phytoplasmas moved from the inoculated twig (or scion) to the main stem, which took 28 days. Afterward, the phytoplasma migrated faster and took less than 4 days to spread into the roots from the main stem. All twigs were then successively colonized by the JWB phytoplasmas from the bottom to the top. JWB phytoplasma was detected via nested PCR in all parts of the periwinkle seedling 82 days after inoculation. Based on these results, the inoculated JWB phytoplasma appeared to migrate downward to the roots along the main stem during the early stages, and then continued to move upward, colonizing twigs along the way until they reached the apex.

• The Plant Pathology Journal
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• v.37 no.2
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• pp.124-136
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• 2021

Bark canker, wood discoloration, and wilting of the duku tree (Lansium domesticum) along the watershed of Komering River, South Sumatra Province, Indonesia first appeared in 2013. The incidence of tree mortality was 100% within 3 years in badly infected orchards. A Ceratocystis species was consistently isolated from the diseased tissue and identified by morphological and sequence analyses of the internal transcribed spacer (ITS) and β-tubulin regions. Pathogenicity tests were conducted and Koch's postulates were confirmed. The fungus was also pathogenic on Acacia mangium, but was less pathogenic on mango. Partial flooding was unfavourable for disease development. Two described isolates (WRC and WBC) had minor variation in morphology and DNA sequences, but the former exhibited a more pathogenic on both duku and acacia. The ITS phylogenies grouped the most pathogenic isolate (WRC) causing wilting of the duku tree within the aggressive and widely distributed ITS5 haplotype of C. fimbriata.

• The Plant Pathology Journal
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• v.37 no.5
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• pp.437-445
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• 2021

Tilletia laevis Kuhn (syn. Tilletia foetida (Wallr.) Liro.) causes wheat common bunt, which is one of the most devastating plant diseases in the world. Common bunt can result in a reduction of 80% or even a total loss of wheat production. In this study, the characteristics of T. laevis infection in compatible wheat plants were defined based on the combination of scanning electron microscopy, transmission electron microscopy and laser scanning confocal microscopy. We found T. laevis could lead to the abnormal growth of wheat tissues and cells, such as leakage of chloroplasts, deformities, disordered arrangements of mesophyll cells and also thickening of the cell wall of mesophyll cells in leaf tissue. What's more, T. laevis teliospores were found in the roots, stems, flag leaves, and glumes of infected wheat plants instead of just in the ovaries, as previously reported. The abnormal characteristics caused by T. laevis may be used for early detection of this pathogen instead of molecular markers in addition to providing theoretical insights into T. laevis and wheat interactions for breeding of common bunt resistance.

• Journal of Korean Society of Forest Science
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• v.75 no.1
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• pp.25-31
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• 1986

In order to contribute to the Korean tea-plant culture and tea industry by means of increasing the production of tea-plants, I have performed the tissue culture of the organs of the anther, leaf and stem. As for the culture-material, I have used the anther of tea (Thea sinensis) at the tetrad uninucleate microspore stage and used medium of modified Murashige and Skoog as the basal medium supplemented with the growth regulators of NAA and 2, 4-D, yeast, kinetin and others at various concentrations. As for the handling of material, I have followed the common methods of sterilization and microtoming and paraffine imbedding method and observed systematically periodic changes of the microspores in culture. I have divided the leaf, stem and root into segments and sterilized them and used the modified Murashige and Skoog as the basal medium and observed the differentiation of roots and callus and the results are as follows. 1. In case of anther, I have found 2n callus was found in 30 out of 100 segments in M2 medium. 2. The differentiation of roots appeared in 24.5% of total leaf segments cultured and in 50.5% of stem and in 43.9% of root. 3. When the differentiation of stem in different parts was observed, the most frequent differentiation was found in the second part of all the 4 parts. 4. The most frequent formation of callus was noticed from the anther-walls in case of anther culture and from the veins in case of leaf culture. It is concluded that the seedlings of tea-plant could be multiplied most by means of tissue culture of the second part of the tea-plant stem and reduction in the expenditures of tea-plant propagation was possible through tissue culture.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.43-48
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• 2004

As an initial step for future genetic manipulations to improve forage characteristics of Italian ryegrass (Lolium multiflorum Lam.), an efficient tissue culture system was established and the factors affecting plant regeneration were evaluated. MS medium containing 5mg/L 2,4-D was optimal for embryogenic callus induction from mature seed and had a strong effect on successive plant regeneration. The plant regeneration frequency was observed at above 70％ when embryogenic calli induced were transferred to N6 medium supplemented with 1mg/L 2,4-D and 5mg/L BA. Among several basic media tested, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. Genotype was an important factor in plant regenerability. 'Jeanne' showed the highest regeneration frequency of 73％. A short tissue culture period and high-frequency regeneration system established in this study will be useful for molecular breeding of Italian ryegrass through genetic transformation.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.187-193
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• 2005

In an effort to optimize tissue culture conditions for genetic transformation of tall fescue (Festuca arundinacea Schreb.), an efficient plant regeneration system from seed-derived calli was established. MS medium containing 6 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.1 mg/L benzyladenine (BA) were optimal for embryogenic callus formation from mature seed and had a strong effect on successive plant regeneration. The plant regeneration frequency above 50% was observed when embryogenic calli induced in this medium were transferred to N6 medium supplemented with 1 mg/L 2,4-D and 3 mg/L BA. Among several basic media, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. 'Kentucky-31' showed to have high frequencies of embryogenic callus induction and plant regeneration up to 58.3 and 50%, respectively. Addition of sucrose to the regeneration medium as a carbon source increased regeneration frequency up to 55%. A short tissue culture period and high-frequency regeneration system established in this study will be useful for molecular breeding of tall fescue through genetic transformation.