• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.176-176
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• 2017

Hydropriming had positive effects on the time for germination to reach 50%, the germination index, the time to final germination percentage, and the number of uniform seedlings with enlarged cotyledons in in vitro germination of small watermelon. In addition, the highest shoot initiation was obtained from hydroprimed cotyledonary nodes ($95{\pm}6%$), followed by non-primed cotyledonary nodes ($78{\pm}6%$), hydroprimed cotyledons ($72{\pm}4%$), and non-primed cotyledons ($48{\pm}4%$). Meanwhile, no shoots were initiated from hypocotyls. The total number of shoots that initiated from cotyledonary nodes and cotyledon explants was insignificant, indicating that both cotyledons and cotyledonary node were good sources for the in vitro culture. Choosing explant sources that favor tetraploidy should be the key for producing higher polyploidy plants; a total of 10.5% of tetraploid regenerants were entirely identified from cotyledon explants. Cotyledons with highly differentiated cells might show higher variations than cotyledonary nodes with more preexisting meristematic cells. Cells of cotyledon tissue might undergo changes in ploidy level during differentiation of the culture, or it might be that some of the variations were already present in the tissues of the donor plant. Morphological changes in fruit length of tetraploid regenerants are genotype-dependent.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.290-290
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• 2005

• 식물조직배양학회지
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• 제22권4호
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• pp.213-213
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• 1995

• Plant Biotechnology Reports
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• 제2권1호
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• pp.33-39
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• 2008

In this paper, we would like to show unexpected morphogenic potential of cell suspensions derived from seedling explants of Gentiana kurroo (Royle). Suspension cultures were established with the use of embryogenic callus derived from seedling explants (root, hypocotyl and cotyledons). Proembryogenic mass proliferated in liquid MS medium supplemented with $0.5mg\;l^{-1}$ 2,4-D and $1.0mg\;l^{-1}$ Kin. The highest growth coefficient was achieved for root derived cell suspensions. The microscopic analysis showed differences in aggregate structure depending on their size. To assess the embryogenic capability of the particular culture, 100 mg of cell aggregates was implanted on MS agar medium supplemented with Kin ($0.0-2.0mg\;l^{-1}$), $GA_3$ ($0.0-2.0mg\;l^{-1}$) and AS ($80.0mg\;l^{-1}$). The highest number of somatic embryos was obtained for cotyledon-derived cell suspension on $GA_3$-free medium, but the best morphological quality of embryos was observed in the presence of $0.5-1.0mg\;l^{-1}$ Kin, $0.5mg\;l^{-1}$ $GA_3$ and $80.0mg\;l^{-1}$ AS. The morphogenic competence of cultures also depended on the size of the aggregate fraction and was lower when size of aggregates decreased. Flow cytometry analysis reveled luck of uniformity of regenerants derived from hypocotyl suspension and 100% of uniformity for cotyledon suspension.

• Journal of Plant Biotechnology
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• 제39권3호
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• pp.133-139
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• 2012

The influences of ethylene inhibitors ($AgNO_3$ and silver thiosulfate) and cytokinins (BAP and TDZ) on shoot regeneration from cotyledon and hypocotyl explants of B. napus cv. Youngsan were investigated. The presence of $50{\mu}M$ Silver thiosulfate (STS) in shoot regeneration medium formed shoots at 60-68% after 3-4 weeks of culture, which was enhanced by 2-fold compared to that of Silver nitrate ($AgNO_3$). Moreover, cotyledon explants were more regenerative than hypocotyls; shoots from cotyledon explants began to occur 4-5 days earlier than that of hypocotyl explants. TDZ at a concentration of $8-10{\mu}M$ was effective for shoot regeneration, compared with BAP. Consequently, the optimal shoot regeneration response was observed in medium supplemented with $50{\mu}M\;STS+8{\mu}M\;TDZ$. In transmission electron microscopy (TEM) analysis, higher density of silver nanoparticles was shown to be accumulated widely inside the cell wall and plasmodesmata of regenerating leaf cultured in medium supplemented with $AgNO_3$. By contrast, in the cell cultured in medium with STS, fine-grained deposits were partly observed in the surroundings of the cell wall.

• Journal of Plant Biotechnology
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• 제50권
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• pp.89-95
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• 2023

In order to investigate the effect of carbon sources on somatic embryogenesis and cotyledon number variations in carrot, embryogenic callus were cultured in the medium supplemented with various concentrations of sucroseor glucose, and with combination of 2% sucrose and various concentrations of mannitol or sorbitol. The maximum number of somatic embryos formed per flask (1,555.70) was obtained in the medium supplemented with 2% sucrose rather than glucose alone or a combination of mannitol or sorbitol and 2% sucrose, and the number of somatic embryos was decreased with the increasing of mannitol or sorbitol concentration. The frequencies of somatic embryos with two cotyledons were 35.14% for sucrose, 19.88% for glucose, 32.55% for mannitol + 2% sucrose, and 38.59% for sorbitol + 2% sucrose, respectively, and the frequencies of abnormal somatic embryos having 3 or more cotyledons were 64.86% for sucrose, 80.12% for glucose, 67.44% for mannitol + 2% sucrose, and 61.41% for sorbitol + 2% sucrose, respectively. Particularly, the frequency of somatic embryos with two cotyledons (59.16%) was the highest in the 2% sucrose medium compared to the frequency of abnormal somatic embryogenesis with three or more cotyledons, and the frequency gradually decreased with increasing concentration of glucose, mannitol or sorbitol. According to these results, it was found that the ratio of abnormal somatic embryo was higher than the normal somatic embryo in carrot, and was shown that somatic embryogenesis and the cotyledon number was affected by the concentrations of sucrose, glucose as carbon source, and mannitol and sorbitol as osmotic agents in culture medium.

• Journal of Plant Biotechnology
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• 제2권1호
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• pp.21-24
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• 2000

An efficient method of shoot regeneration of peanut is described. In vitro shoot organogenesis from the callus of cotyledon explants of Arachis hypogaea L. was stimulated by addition of Adenine sulphate (Ads) along with 6 - benzylaminopurine (BAP) and - napthalene acetic acid (NAA). Ads (13 ${\mu}{\textrm}{m}$) had a stimulatory effect on shoot bud differentiation when combined with BAP (13 ${\mu}{\textrm}{m}$) and NAA (2 ${\mu}{\textrm}{m}$). Shoot organogenesis was markedly higher (92%) from callus induced on Ads, BAP and NAA combined media than from those formed by the individual supplementation of Ads or BAP with NAA. The shoots elongated on the media with GA$_3$ (1 ${\mu}{\textrm}{m}$). Elongated plantlets rooted with MS media containing IBA (9 ${\mu}{\textrm}{m}$).

• Journal of Plant Biology
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• 제37권2호
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• pp.159-166
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• 1994

Direct current (DC) applied to cotyledons during a 16 h inductive dark period inhibited the flowering in the short-day plant, Pharbitis nil Choisy cv. Violet. The inhibitory effect of DC was more profound when the current flowed from roots to cotyledons, showing its polarity-dependent action. The second half on the inductive dark period was more sensitive to DC stimulus. The flowering was significantly depressed only when DC stimuli were applied to the translocation path of the floral stimulus from the induced cotyledon to the apex, suggesting that the transport of floral stimulus was damaged by the DC treatment. The vegetative apex culture bioassay system showed that a significant level of the floral stimulus activity existed in the phloem exudate from the cotyledons which would fail to form their own floral buds. These results strongly support the hypothesis that DC partially impede, at least temporarily, the transmission path of the floral stimulus from florally-induced cotyledon to the apex, rather than depressing in situ synthesis of the floral stimulus.

• 식물조직배양학회지
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• 제22권5호
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• pp.291-298
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• 1995

시호(Bupleurum falcatum L.)의 잎절편으로부터 체세포배형성을 통한 식물체 재생과 체세포배 발생의 이상을 일으키는 2,4-D의 영향에 대하여 또한 체세포배의 자엽수와 발아와의 관계에 대하여 기술하였다. 배발생능 캘러스는 1mg/L 2,4-D가 첨가된 MS 고형기본배지에서 배양된 캘러스로부터 선발하였다. 2,4-D 첨가 MS 기본배지에서 6주간 배양후 3주간 2,4-D가 제거된 배지에서 배양하여 체세포배 발생과 비정상적인 체세포배의 자엽발생을 관찰하였다. 이상자엽의 빈도는 정상인 2개 자엽에서 65% 인데 비하여 1개의 자엽에서 7%, 3개의 자엽을 갖는 체세포배에서는 25%, 4개 자엽에서는 5%, 5개 자엽에서 2% 및 나팔형 자엽배는 3% 이었다. 2개의 정상적인 자엽을 갖는 체세포배의 발아율이 80%인 것에 비하여 1, 3 4, 5개의 자엽을 갖는 체세포배에서는 25%, 58%, 38% 및 20%로 발아율이 낮았다. 그러나 나팔형의 비정상 체세포배는 전혀 발아되지 않았다. 다자엽배의 구조는 체세포배의 뿌리 또는 배축에서 원통상전형성층을 나타내었지만 자엽절에서는 자엽수와 동일한수의 전형성층속으로 분포되었다. 체세포배의 자엽수 변이는 전형성층의 수와 밀접한 관계가 있다.

• 식물조직배양학회지
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• 제27권3호
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• pp.227-232
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• 2000

당근 유식물체의 자엽을 절편으로 유도된 배형성능 세포를 여러가지 농도의 카드뮴 (0, 50. 100, 200. 500, 1000 $\mu$M)이 첨가된 MS 액체배지에 배양한 다음 MS 기본배지에 옮겨서 체세포배 발생을 유도했고 한편 카드뮴 처리구와 카드뮴이 처리되지 않은 대조구에서 체세포배를 얻었다. 현탁배양에서 정상적인 2개의 자엽을 갖는 체세포배 발생은 카드뮴 첨가 배지에서 감소하였으나 비정상적인 3개의 자엽을 갖는 체세포배가 많이 관찰되었다. 또한 비정상적인 1개, 3개 및 4개의 자엽을 갖는 체세포배보다 정상적인 2개의 자엽을 갖는 체세포배의 식물체 재생률이 가장 높았다. 카드뮴 처리구에서 발생된 체세포배의 발아율은 자엽수에 관계없이 대조구에서 발생된 체세포배의 발아율에 비해 감소하였다.