• Proceedings of the Korean Society of Crop Science Conference
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• 1994.06a
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• pp.166-167
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• 1994

• Proceedings of the Korean Society of Crop Science Conference
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• 1994.06a
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• pp.168-169
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• 1994

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.10a
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• pp.156-156
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• 2004

• Journal of Plant Biotechnology
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• v.49 no.1
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• pp.74-81
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• 2022

Brassica napus, an oil crop that produces rapeseed oil, is an allotetraploid (AACC, 2n = 38) produced by natural hybridization between B. rapa and B. oleracea. In this study, microspore was cultured using the F₁ developed from a cross between 'EMS26' line with high oleic acid content and 'J8634-B-30' lines. The flower bud size showing the nuclear development at the late uninucleate and binucleate stage with high embryogenesis rate was 2.6 ~ 3.5 mm. Microspores were cultured using only this size and after then most microspore embryo developed into secondary embryos and then regeneration plants obtained from the developed multilobe. The analysis of the ploidy of the plants revealed that 66.7% and 27.8% of the total lines were tetraploids and octoploids, respectively. The sizes of stomatal cells in tetraploids, octoploids, and diploids were 25.5, 35.6, and 19.9 ㎛, respectively, indicating that ploidy level was positively correlated with cell size. Furthermore, 62 tetraploid doubled haploid (DH) lines were selected. The average oleic acid (C18:1) and linolenic acid (C18:3) concentrations of DH were 72.3% and 6.2%, respectively. Oleic acid and linolenic acid concentrations exceeded the two parental values in 5 and 14 DH lines, respectively, suggesting that these two fatty acids had transgressive segregation. Therefore, the DH population can be utilized for the biosynthesis of unsaturated fatty acids in rapeseed and related genes. It can also be used as a breeding material for varieties with high oleic acid concentrations.

• Journal of Life Science
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• v.19 no.8
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• pp.1016-1022
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• 2009

Tapetum is the tissue in which nutrients are supplied to the developing microspore in angiosperm anther. At tetrad stage of microspore, the tapetal cells show maximum development, but they began to be degenerated by apoptotic programmed cell death (PCD) after sporopollenin accumulation in the pollen wall. The initial step of PCD was observed as vacuolar fusion. After that, cytoplasmic condensation and nuclear fragmentation followed. Lipid droplets are degenerated at a relatively late stage of PCD, and orbicular bodies are the last remains in tapetal cells. The cell wall was relatively resistant against vacuolar enzymes in tapetal cells; it was considered the last structure remaining during programmed cell death of tapetum in ginseng anther.

• Korean Journal of Plant Resources
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• v.18 no.2
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• pp.302-308
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• 2005

This study was carried out to obtain the basic informations on the characteristics of gametophytes formation and embryo developement in Dicentra spectabilis. Microspore mother cells developed from archesporial cells, start meiosis when flower bud length reaches around 1 mm, formed tetrahedral type tetrad. The 4 microspores were separated. They were developed to male gametophytes, respectively. Megaspore mother cells were observed when flower bud length was $4{\sim}5\;mm$. The developemental type of megaspore was polygonum and embryo sac was amphitropous. Three large and distinctive antipodals did not degenerated and remained after embryo sac was developed. When the male and female gametophytes was fully developed, the length of stamen and style was very similar or stamen was shorter about 0.5 mm than that of style. This result indicates that self-fertilization can be occurred in this species. After fertilization, developing zygotic embryos showed various stages of development from globular to cotyledonary embryos, and zygotic embryo in seed scattering time seemed to have an early cotyledonary stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.443-448
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• 2001

This study was carried out to obtain the basic informations on the characteristics of gametophytes formation and microspore germination in Astragalus membranaceus Bunge. Pollen mother cells passed through meiosis when the flower bud length reaches around 3.5 mm, thus creating the tetrad when it is 4.0 mm long. Pollen attains full growth when the bud is about 10.0 mm long and the anther is found to dehisce when the length of tate bud reach around 12.0 mm. Embryo sac develops at a similar speed as pollen did and it attains its full growth when the bud is about 10-12 mm long. After being stored at 4$^{\circ}C$ or -4$^{\circ}C$, the pollen maintained its germination ability to almost full extent by the 30th day after store. However, the germination rate at room temperature (23~28$^{\circ}C$) decreased below 3％ by the 3rd day of storage and so did the germination speed.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.229-238
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• 2021

The selective permeate transport characteristics of iodine ion at follicle cell membrane model in thyroid which irradiated by high energy x-ray(linac 6 MV) was investigated. The follicle cell membrane model used in this experiment was a polysulfonated copolymerized membrane of poly(4-vinylpyridine-co-acrylonitrile:VP-AN). The difference of membrane thickness [2 mole AN%(w/w)], fixed carrier concentration[VP-AN%(w/w)], OH- concentration were occurred at difference of I- concentration and quantity of thyroid hormone, respectively. The tensile strength in fixed carrier concentration[VP-AN% (w/w): 0-62 %] of irradiated membrane was found to be decreased about 1.2-1.8 times than non-irradiated membrane. The I- selective permeate initial flux with increase of membrane thickness [2mole AN%(w/w)], fixed carrier concentration[VP-AN%(w/ w)], OH- concentration in irradiated membrane were found to be decreased about 2.1-4.5 times, about 2.2-2.5 times, about 2.1-2.67 times than non-irradiated membrane, respectively. As a result, the quantity of thyroid hormone was decreased at irradiated membrane than non-irradiated membrane. The decrease of thyroid hormone was occurred at hypothyroidism and hyperthyroidism, thyroid cancer, and so on. As the thyroid hormone in cell membrane model were abnormal, cell damages were appeared at cell.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.71-76
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• 1999

Anthers of two hot pepper cultivars, Milyang-jare and Geryongsan-jare, were cultured on MS medium containing 0.1 mg/L 2,4-D and 0.1 mg/L kinetin. The influence of pretreatment at 4$^{\circ}C$ and 32$^{\circ}C$ on induction of microspore embryo was investigated. Milyang-jare was superior to the Geryongsan-jare in microspore embryo induction. The 32$^{\circ}C$ pretreatment increased embryo induction compared to the 4$^{\circ}C$ pretreatment while the 4$^{\circ}C$ pretreatment stimulated callus induction. Microspore embryos were regenerated to plantlets in the same medium or hormone free medium at 32$^{\circ}C$ treatment but most embryos failed to develop directly into plantlets at 4$^{\circ}C$ treatment. The optimal period of the 32$^{\circ}C$ pretreatment was 3 days in Milyang-jare and 6 days in Geryongsan-jare. The 32$^{\circ}C$ pretreatment was essential for induction and growth of microspore embryo in pepper.

• Journal of Plant Biotechnology
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• v.38 no.1
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• pp.30-41
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• 2011

The influences of the agitation as well as the addition of medium during culture on the production of embryos were invested in isolated microspore culture of hot pepper (Capsicum annuum L.). When the culture medium was added during initial liquid culture step of liquid-double layer culture, the embryo yield and quality greatly increased. The most effective time point for medium addition was 5 days after the culture commenced. On the other hand, the effect of medium addition at later double layer culture step in liquid-double layer culture on the embryo production was less compared to that of medium addition during the initial liquid culture step. Agitating the culture for 1 week during later double layer culture step in liquid-double layer culture effectively increased the production of normal cotyledonary embryos. In the case of liquid culture, agitating the culture for 1 week from 7 days after the culture commenced was also effective for embryo development. However, when the total agitation time was longer (2 to 3 weeks) during liquid-double layer culture or liquid culture, the embryos developed abnormally in both cases. The normal cotyledonary embryos obtained in this study successfully developed to plants when transferred to regeneration media. These regenerated plants were either diploid or haploid, and there was a difference in the number of chloroplasts between guard cells of diploid and haploid. These results can be used as an important data for developing an efficient microspore culture system with high quality embryo production in hot pepper.