• Journal of Plant Biotechnology
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• 제2권3호
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• pp.123-128
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• 2000

To enhance in vitro plantlet regeneration efficiency of soybean through embryogenesis, the culture conditions such as material part and size of immature seed, 2,4-D, pH and solidifying agents for somatic embryogenesis were investigated. Somatic embryogenesis was induced from the immature embryo, immature cotyledon and embryonic axis explants of the immature seed on MS medium supplemented with 2.0 mg/L 2,4-D. The highest rate (up to 22.9%) of somatic embryogenesis was obtained from the immature cotyledon, following embryonic axis and the immature embryo. The rate varied with the developmental stages of seed. The maximum rate (25.4%) of embryogenesis was obtained from 3-4 mm length of the seed (after 25 days of flowering). The optimum concentration of 2,4-D for embryogenesis was 10 mg/L. The optimum pH was at 5.8 and solidifying agent for medium was better with 0.4% gelrite than with agar. For rapid multiplication of shoot tips from the germinating somatic embryos, they were cultured on MS medium containing 2 mg/L indole-3-butyyic acid (IBA) and 1 mg/L 6-benzyladenine (BA). After then somatic embryos with one and three cotyledons were transferred to the growth regulator free medium. The medium exhibited the higher rate (ca. 50%) of development than the multiplication medium.

• Journal of Plant Biotechnology
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• 제48권1호
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• pp.44-53
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• 2021

The present work aims to study the induction of somatic embryogenesis in cork oak (Quercus suber L.) from immature zygotic embryos and young apical leaves obtained from 2-month-old seedlings through acorn germination on sterilized peat. The immature zygotic embryos were grown for 1 month on the mineral solution of MS in the presence of 4.52 µM 2,4-D and 30 g/L sucrose. They were then transferred to the same mineral solution with no added growth regulators. In the third subculture, yellow somatic embryos, characterized by two voluminous cotyledons, were differentiated from the radicle of the immature zygotic embryos. The induction of somatic embryogenesis in young leaves required a series of transfers on different culture media containing 30 g/L sucrose and 100 mg/L myo-inositol. Secondary or recurrent somatic embryogenesis occurred within the immature somatic embryo radicles after 1 month of culture on growth regulator-free medium containing WPM macronutrients, MS micronutrients, and vitamins.

• Journal of Crop Science and Biotechnology
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• 제11권2호
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• pp.119-126
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• 2008

Since somatic embryogenesis combined with ethylmethane sulfonate(EMS) treatments is the most efficient technique for mutagenesis, the embryogenic capacity of four soybean cultivars was evaluated at different EMS concentrations, treatment times, and preculture durations. Two to 4 mm long immature cotyledons were placed in induction medium after EMS treatment, and the numbers of somatic embryos formed per explant were counted four weeks after culture initiation. We observed genotypic differences in the efficiency of somatic embryogenesis from immature embryos among four cultivars treated with different concentrations of EMS for six hours. Cultivars, Sinpaldalkong 2 and Jack, displayed highly efficient somatic embryogenesis regardless of EMS concentration, whereas very low efficiency or no survival was observed in Jinju 1 and Iksannamulkong cultivars. Preculture duration did not influence the efficiency of somatic embryogenesis. Because Sinpaldalkong 2 exhibited the best somatic embryogenesis, much higher concentrations of EMS were used to test somatic embryo formation under different periods of time in this cultivar. Three and six hour treatments with both 1 and 2 mM EMS yielded higher embryo formation than longer periods of time. Increasing the time with embryos in 2 mM EMS caused a reduction in somatic embryogenesis in Sinpaldalkong 2, but many chlorophyll-deficient soybean variants were identified in the $M_1R_0$ and $M_2R_1$ generations. In addition to Jack, Sinpaldalkong 2 is a good genotype for plant regeneration from EMS-treated immature embryo cultures.

• Journal of Plant Biology
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• 제39권2호
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• pp.127-135
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• 1996

An efficient system of somatic embryogenesis was established for the red pepper plant (Capsicum annuum L. cv. Nokkwang) usign immature zygotic embryos. The size of the immature zygotic embryos and the concentrations of 2, 4-D and sucrose were found to be critical. Somatic embryos were induced via callus or directly from explants and regenerated into plantlets successfully. When zygotic embryos 1~2 mm long were cultured on the modified Murashige-Skoong (MS) medium supplemented with 2 mg/L 2, 4-D for 3 weeks in the dark, somatic embryos were induced directly from the apical region of zygotic embryos with the highest frequency being approximately 90%. To mature the somatic embryos, ABA and an ethylene inhibitor AgNO3 were used. The highest frequency of shoot regeneration (25% in each) resulted at 2$\mu$M ABA or 20$\mu$M AgNO3 treatment at rates 3.7 and 1.6 times control, respectively. Shoots developed mainly from the cotyledonary node on CoCl2-containing medium, and from the upper side of cotyledon on medium containing AgNO3 while the embryos on the control medium produced shoots from both the cotyledonary node and the upper region of cotyledons both at frequencies of 50%. Indirect somatic embryogenesis via callus was induced at an efficiency of approximately 10% with zygotic embryos 3~4 mm long cultured on MS medium containing 5~10 mg/L, 2, 4-D for 5~7 weeks under a continuous light condition. The plants regenerated from the somatic embryos were morphologically normal. Using scanning electron microscopy, the direct and indirect somatic embryogeneses were observed to follow the globular, heart and torpedo stages, similar to zygotic embryogenesis. Also, suspensors appeared in the early globular and ovoid-shaped late globular embryos during indirect somatic embryogenesis.

• Journal of Plant Biology
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• 제37권3호
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• pp.333-341
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• 1994

Effective plant regeneration from immature cotyledons of soybean [Glycine max (L.) Merr.] cultivars was achieved via somatic embryogenesis. Somatic embryogenesis was performed with the cotyledons of immature embryos 14-20 d after flowering. Immature cotyledons of cv. Whangkeum were placed abaxial or adaxial side down on modified MS medium containing 20mg/L 2,4-D. The greatest number of somatic embryos, 1.2 per cotyledon, was produced from those of 4.0-4.9 mm in length which had been placed abaxial side down. Among cvs. Pecking, Whangkeum and Baekwoon, Pecking had the highest embryo induction efficiency with 4.3 somatic embryos per cotyledon in 20mg/L 2,4-D treatment and with 1.0 embryo per cotyledon in 8mg/L NAA treatment. Germinable globular somatic embryos were induced with the highest efficiency, 27.6%, in 20mg/L 2,4-D and were proliferated efficiently on liquid medium containing 10mg/L 2,4-D. The globular somatic embryos developed into germinable mature somatic embryos on medium containing 10 $\mu$M CoCl2, 9% sucrose, and 0.5% activated charcoal. These mature somatic embryos germinated on hormone-free mediu. After transfer to the soil, regenerated plants with seeds were obtained.

• 한국작물학회지
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• 제56권3호
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• pp.279-283
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• 2011

The immature embryos during seed development were examined to predict the suitable embryos for an efficient regeneration system. Five spring wheat genotypes and five winter wheat genotypes were tested using immature embryos as explants. Spring wheat genotypes showed much higher levels of plant regeneration than those of winter wheat genotypes. The highest frequencies of embryogenesis and regeneration were obtained when embryos at 13-14 days after anthesis (DAA) were used as explant and decreased using embryos at 21-22 DAA during seed development. Significant differences were also found for callus induction and regeneration as affected by immature embryo size. The regeneration efficiency was drastically decreased in spring and winter wheat genotypes when embryos larger than 2.0 mm of length were used. The optimum developmental stage and embryo length for regeneration efficiency were at 13-14 DAA and 1.0-1.5 mm, respectively. The selection of suitable embryos for the high frequencies of embryogenesis and regeneration leads us to efficient genetic improvement of wheat.

• Plant Biotechnology Reports
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• 제2권4호
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• pp.259-265
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• 2008

Picea koraiensis, called Korean spruce, is an evergreen tree and found mostly in northeast Asia. In this study, plant regeneration via somatic embryogenesis from open-pollinated immature zygotic embryos of nine geno-types of elite trees was established. Immature zygotic embryos were cultured onto RJW medium modified from 505 medium with $21.48{\mu}M$ NAA, $2.22{\mu}M$ BA, and $2.32{\mu}M$ KT. The average frequency for all nine genotypes was 74.2%. Embryogenic calluses of the nine genotypes of elite trees were subcultured on RJW basal medium containing $8.06{\mu}M$ NAA, $1.11{\mu}M$ BA, and $1.16{\mu}M$ kinetin. The calluses of three lines, $3^{\sharp}$, $9^{\sharp}$, and $2^{\sharp}$, were actively proliferated but others were not. Somatic embryogenesis was induced from the embryogenic callus in genotypes of $3^{\sharp}$, $9^{\sharp}$, and $2^{\sharp}$ on RJW medium with ABA and $60g\;l^{-1}$ sucrose. Cotyledonary somatic embryos were subjected to a drying process. The drying of embryos by uncapping the culture bottle for 5 days on a clean bench resulted in a high frequency of germination of somatic embryos (87% in RJW medium). However, plantlet conversion from germinated embryos was greatly reduced and the optimal medium for plant conversion was 1/2 WPM or 1/2 BMI medium. In conclusion, we have, for the first time, established a plant regeneration system via somatic embryogenesis in the Korean spruce, which can be applied for rapid micropropagation of elite trees.

• 한국작물학회지
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• 제65권4호
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• pp.365-376
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• 2020

미성숙배를 이용한 조직배양은 높은 재분화율로 인하여 밀 형질전환에 적용하기 위한 가장 좋은 방법이지만 매우 한정적인 수집시기와 생육조건으로 인해 이용하기 위한 시간의 제한과 많은 노동력이 집약되어있다. 따라서 안정적이고 지속적인 미성숙배 수집을 위해 스피드 브리딩 조건을 이용하여 출수가 촉진된 밀 이삭을 이용한 미성숙배 조직배양의 효율을 검정하였고, 연구결과는 다음과 같다. 1. 스피드 브리딩 조건의 출수기는 정상조건과 비교하여 36일에서 54일까지 단축되었으며, 개화 후 11일 된 영과에서 수집된 미성숙배 조직배양의 재분화율과 소식물체 출현 비율은 정상조건과 비교하여 유의한 차이가 없다는 것을 확인하였다. 2. 두 배양 조건에서 항산화 효소 활성 분석 결과 차이가 나타나지 않았으며, 연관 표지 유전자 발현 검정을 통하여 일장과 세포분열과의 관계를 검정하여 스피드 브리딩 조건에서 수집된 이삭의 안정성을 검정하였다. 3. 본 연구 결과는 스피드 브리딩 조건을 활용한 미성숙배 조직배양에 활용될 것이며 관련 유전자 발현 및 항산화 활성 검정 결과를 통해 검증된 안정적 미성숙배는 밀 형질전환 기술 개발에 활용될 수 있을 것으로 사료된다.

• Journal of Plant Biotechnology
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• 제7권3호
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• pp.187-193
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• 2005

A protocol was developed for somatic embryogenesis with 100% induction rate from immature zygotic embryo axes of peanut (Arachis hypogaea L. cv. DRG-12) cultured on MS medium containing $18.09\;{\mu}M$ 2,4-D. The frequency of somatic embryogenesis (31.7%) as well as the number of somatic embryos induced per explant (6.6) decreased when the concentration of 2,4-D was increased to $72.4\;{\mu}M$. Morphologically abnormal somatic embryos were observed at a frequency of 43.3% on MS medium containing $72.4\;{\mu}M$ 2,4-D. Somatic embryos isolated from 30-day-old cultures of immature zygotic embryo axes exhibited precocious germination with varied responses when placed on MS basal medium with 3% sucrose. Maximum shoot induction (80.0%) was observed from somatic embryos isolated from 60-day-old cultures of immature zygotic embryo axes when placed as a clump rather than individually on MS medium supplemented with $26.63\;{\mu}M$ BA and $0.54\;{\mu}M$ NAA. Shoots developed from somatic embryos rooted with higher frequency (93.3%) on Blaydes' medium containing $5.4\;{\mu}M$ NAA.

• 식물조직배양학회지
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• 제22권5호
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• pp.299-306
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• 1995

본 실험은 강활(O. koreanum)과 지리강활(A.purpuraefolia)의 체세포배 발생을 위한 효율적인 세포배양시스템을 확립하고자 실시하였다. 강활과 지리강활의 개화후 3주된 미숙종자는 0.1 mg/L 2,4-D와 0.1 mg/L BA 혼용처리구에서 배발생캘러스와 체세포배 발생이 가장 양호하였고, 0.1-3.0mg/L NAA가 처리된 배지에서 재분화된 식물체의 자엽과 배축의 가장자리로부터 직접 체세포배가 발생하였다. 미숙종자의 휴면을 고려하여 저온처리한 결과, 5$^{\circ}C$에서 10일동안 저장 후, 25$\pm$2$^{\circ}C$에서 배양하였을 때 반응이 없던 배양체로부터 배발생 캘러스와 체세포배가 발생하였고 이 체세포배는 줄기와 뿌리로 분화되었다. 지리강활에서는 배지내 첨가한 glutamine과 coconut milk의 뚜렷한 효과가 인정되지 않았다. 그러나 강활의 경우에는 대조구에 비하여 glutamine과 10% coconut milk가 포함된 배지에서 체세포배 발생률이 항상되었고 특히 glutamine은 coconut milk에 비해 NH$_4$NO$_3$ 대체효과가 인정되었다. 체세포배의 器內 식물체전환율은 MS 기본배지에서 89.1%로 가장 양호하였고 배발생 캘러스의 증식용 배지로는 0.01 mg/L 2,4-D와 0.01 mg/L BA혼용처리구에서 가장 좋았다.