• Journal of Plant Biology
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• v.33 no.4
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• pp.271-276
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• 1990

Our study was carried out for plant regeneration via somatic embryogenesis from immature seeds of Bletilla striata. The highest frequency of embryogenic callus formation was obtained from the immature seeds (at 150 days after pollination) cultured on Hyponex and VW medium supplemented with 3 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 mg/l kinetin under the dark condition. Multiple somatic embryos were induced when embryogenic callus was transferred to VW medium without growth regulators under continued illumination. Somatic embryos were observed histologically with scanning electron microscopy. Regeneration of Bletilla striata was obtained from somatic embryos with a well-defined scutellum and coleoptile as well as with one or more shoot primordia and root primordia. We think that these methods for orchid multiplication must be useful to access clonal propagation of orchids.

• Mycobiology
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• v.34 no.4
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• pp.206-208
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• 2006

To produce an artificial fruiting body of Armillaria mellea on the oak sawdust medium, seven strains of A. mellea were used. The top surface of oak sawdust medium covered with ground raw carrot was inoculated with each of 7 strains and cultured for 30 days at $25^{\circ}C$ in the dark condition until the mycelia of A. mellea completely colonized the medium from top to bottom. Then, the mycelia which were fully covered on the top surface of the medium were scratched slightly with a spatula and filled with tap water for 3 hours. To induce the primordial formation, the 7 strains of A. mellea were transferred to the growth chamber under the illumination (350 lux) of 12 hours and relative humidity of $85{\pm}5%$ in a day and then cultured at $16{\pm}1^{\circ}C$. Only A. mellea IUM 949 could form primordia on the sawdust medium, but the other strains did not make primordia at the same condition. The primordia of A. mellea IUM 949 were formed 10 days after complete colonization of the medium and the fruiting bodies were produced 7 days after a primordial formation. The experimental results suggested that IUM 949 strain might be a good candidate for mass production of fruiting bodies of A. mellea.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.682-688
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• 2020

Hemp (Cannabis sativa L.) is a dioecious plant, although monoecious plants are bred in some cultivars for fiber or seed production. Recently, hemp has received attention for medicinal use with some cannabinoids, including cannabidiol. Self-fertilization for breeding inbred lines is difficult because of dioeciousness and anemophily in hemp. This experiment was conducted to develop a self-fertilization method by forming female flowers and seeds from male plants of dioecious hemp. To induce the formation of female flowers on male plants, 500 mg L^-1 of ethephon was sprayed on plants at soon, seven and fourteen days after primordia formation. The plant ratio of female flowers formation and the number of harvested seeds were increased by ethephon treatment. Female flowers of male plants have 5 stigmas in contrast to the dual stigma of female 1plants. Male plant seeds were lighter and smaller than those from female plants. Although the germination rate was lower than that of normal seeds from female plants, the seeds from male plants germinated to grow seedlings. Thus, we suggest that hemp plants should be treated with ethephon at soon after primordia formation to induce the formation of more female flowers on the male plants.

• Journal of Life Science
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• v.25 no.1
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• pp.37-43
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• 2015

We have investigated the effects of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), indole-3-acetic acid (IAA) and methyl jasmonate (MeJA) on the development of aerenchyma in the primary root of maize (Zea mays). Because plant hormones affected the longitudinal organization of the primary root, we need an indicator to direct the positions for comparison between control and hormone-treated roots. Therefore, the zones of the maize primary root were categorized as PR25, PR50 and PR75, where each value indicates the relative position between the root tip (PR0) and the base (PR100). Aerenchyma was not observed at PR25 and PR50 and rarely found at PR75 in the cortex of control roots. The aerenchymal area at PR75 increased in the presence of the ethylene precursor ACC or a natural auxin IAA. On the other hand, MeJA differentially acted on non-submerged and submerged roots. Exogenously applied MeJA suppressed the aerenchyma formation in non-submerged roots. When the primary root was submerged, aerenchymal area expanded prominently. The submergence-induced aerenchyma formation was amplified with MeJA. Lateral root primordia have been known to inhibit aerenchymal death of surrounding cells. All the three hormones stimulating aerenchyma formation as described above did not restore the inhibition caused by lateral root primordia, suggesting that the inhibitory step regulated by lateral root primordia can be located after hormonal signaling steps.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.503-514
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• 1997

The morphogenesis of panicle and spikelet in paddy rice has been studied in high yielding Indica$\times$Japonica hybrid cultivar, Milyang 23 and a Japonica type cultivar, Koshihikari. Germinated seeds planted in $5000^{-1}$ a pots filled with submerged soil and cultured under natural conditions. The young panicle of main stem were continuously dissected and observered by Cryo-SEM from the panicle initiation stage until heading stage. Although the date of panicle differentiation and heading in Koshihikari earlier than those of Milyang 23. the sequence of panicle development in two cultivars begins when first bract primordium at opposite side of flag-leaf primordium differentiated, synchronously followed by growth of the primary branch primordia (PBPs) and secondary branch primordia (SBPs), spikelet primordia(SPs), glumes as lateral organs on rachilla and organs composing single floret, and successive sporogenesis in the young spikelets continue after the enclosure by lemma and palea. The PBPs are acropetally initiated from the base of the panicle primordium, and the SBPs alternately differentiate from the base of upper PBP which differentiate later than the lower PBP. Spikelet development starts at the top of upper side PBP of the young panicle and continue basipetally even though SBPs continue to develop at the lower primary branch. Each PBP, SBP and SP differentiate with differentiation bract or bract hair cell around the base of each their primordia. The observation could confirm that Milyang 23 has not only 2~3 more defferentiated PBPs, but also more SBPs and SPs especially from middle-lower primary branch, at end of their differentiation stages, as compared to those of Koshihikari.

• Horticultural Science & Technology
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• v.16 no.4
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• pp.520-524
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• 1998

This study was carried out to investigate the effect of thidiazuron(TDZ) on callus and shoot primordia formation, to determine the most optimum multiple shoot induction medium, and to obtain the plantlets on solid medium via shoot organogenesis. TDZ 0.01 mg/L in MS medium was most effective on callus formation, and BA 0.1 mg/L was most effective on shoot growth, while TDZ 0.01 mg/L was most effective on callus formation. TDZ 0.001 mg/L was most effective in shoot primordia formation. Shoot tips were cultured with TDZ 0.01 mg/L for 8 weeks and induced callus was transferred to regeneration medium containing TDZ 0.001 mg/L. After 4 weeks induced shoot primordia were resubcultured at growth regulator-free medium for 4 weeks. The induced multiple shoots rooted more efficiently at NAA 1.0, 5.0 mg/L, or IBA 5.0 mg/L.

• Applied Microscopy
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• v.8 no.1
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• pp.67-76
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• 1978

A comparative investigation of fine structure of callus cells derived from tissue culture of Panax ginseng was made by electron microscope. Callus was consisted of large superficial cells and small inner zone cells derived from shoot apex tissue cultured for 16 weeks. Large superficial cells were contained the clusters of starch grains surrounded by a double plastid membrane. Especially, electron dense particles were deposited just inside and outside of plastid membrane and also deposited on mitochondria-like and endoplasmic reticulum-like structures. Crystalline body was also found in superficial cells. Small inner zone cells were characterized by presence of proplastids sheathed by short endoplasmic reticulum profiles. presence of spiral configuration of ribosomes and absence of crystalline body. Organ primordia was consisted of a dense cytoplasm and notable nucleate cells derived from nodal tissue cultured for 67 weeks. Proplastids containing starch grains and crystalline bodies were frequently observed; starch grains are of small quantity and does not form the clusters as in inner zone cells; hexagonal crystalline body itself does not have always limiting membrane. Remarkably. in a few cells of primordia, particles resembling the presumptive virus were observed mainly in condensed nuclear chromatin and also in cytoplasm, in mitochondrion-like organelle.

• Mycobiology
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• v.31 no.1
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• pp.46-49
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• 2003

A method of spawn making procedures through the application of fermented sawdust for the purpose of avoiding contamination by undesirable fungi in the course of Pleurotus ostreatus mycelial growth was evaluated. Of three kinds of supplements, rice bran was the most effective to raise temperature up to $70^{\circ}C$. Mycelial activity and density was more considerably improved in the case of using fermented sawdust supplemented with rice bran than the case of non-fermented sawdust. Primordia of Pleurotus ostreatus were formed on fermented sawdust. The substrate of fermented sawdust showed potential to prevent the growth of Trichoderma sp. which caused a symptom on mushroom mycelium, whereas there was nothing to inhibit the growth of Trichoderma sp. during 30 days after inoculation in non-fermented sawdust.

• The Korean Journal of Mycology
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• v.16 no.2
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• pp.95-100
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• 1988

Isozyme band patterns were investigated by isoeletric focusing Esterase and Leucine amino peptidase of Pleurotus spp. in Korea. Esterase patterns of mycelia and fruitbody were distinquished. However, those of primordia, cap and stem were similar. Interspecies differences of Pleurotus ostreatus, P. cornucopiae and P. florida of Esterase zymogram were found. Species identification by electrophoretic zymogram may be a role as an additional taxonomic tool.

• The Korean Journal of Mycology
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• v.28 no.2
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• pp.109-111
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• 2000

Composition of fatty acids (FAs) in Pleurotus ostreatus were analyzed by gas chromatography and compositional changes according to cultivar, fruitbody section and developmental stage (days after primordia formation) were investigated. Major FAs in oyster mushroom were linoleic acid, oleic acid and palmitic acid. Unsaturated FAs were higher in pileus portion than upper- or lower-stipe portion. Oleic acid content was increased with developmental days but linoleic acid content was highest at $3{\sim}4$ days after primordia formation and then decreased after that. And ratio of unsaturated FAs/saturated FAs was decreased with basidiocarp maturation.