• Journal of Plant Biotechnology
• /
• 제30권3호
• /
• pp.269-273
• /
• 2003

In order to develop an efficient micropropagation protocal for Eucalyptus pellita, on in vitro culture system has been was established by inducing axillary buds from greenhouse stock materials. Among 6different media tested, DKW medium was the best ot induce bast induce both shoot proliferation and growth. Average number of proliferated shoots of 403per explant was obtained at the concentration of 0.1mg/LBA. Most of the stem materials excreted phenolic compounds at the proximal part of the explant and caused darking of the media. Therefore, it was necessary to transfer frequently to a fresh medium and/or to add activated charcoal at the concentration of 0.02％(w/v). Generally on vitro roots were formed easily on 1/2DKW medium with NAA treatment. All the explants rooted at the medium containing 0.2mg/L NAA and displayed vigorous root growth in vitro culture conditions. After transferred to an artificial soil mixture (peatmoss: vermiculrite: perlite, 1:1:1, v/v/v) in the greenhouse, most rooted plantlets survived well without any morphological abnormalities. The results show that the species can be micropropagated effectively by the application of axillary bud culture system.

• Journal of Forest and Environmental Science
• /
• 제29권4호
• /
• pp.275-281
• /
• 2013

To establish in vitro nodal culture conditions of Echinosophora koreensis Nakai, one of rare and endangered species famous for beautiful flowers in the Korean Peninsula, the influence of plant growth regulators (PGRs) on shooting and rooting from in vitro shoots was investigated. In shoot multiplication, addition of 6-benzylaminopurine (BA) to the half-strength Driver and Kuniyuki's media in the range of 2.22 to 8.88 ${\mu}M $induced 2.5 to 2.7 shoots per axillary bud; and addition of 2.27 ${\mu}M $ thidiazuron (TDZ) produced 3.2 shoots, during 4 weeks of culture, while zeatin and isopentenyl adenine (2ip) were not effective on shoot multiplication as observed from several combination treatments of BA with other PGRs. Shoots established were smaller than 2 cm in length, in most of the treatments. while in BA 8.88 ${\mu}M $ treatment more than 30% of shoots were longer than 2 cm and shorter than 4 cm. In rooting, naphthalene acetic acid (NAA) from 5.37 to 21.48 ${\mu}M $ showed the rooting rate from 40.0 to 62.5%. Indole butyric acid (IBA) addition had little effect on rooting (<10%), although some roots in IBA-containing media were longer than those in NAA. Micropropagation from axillary buds of nodular explants was applicable and promising to multiplication and conservation of Echinosophora koreensis Nakai.

• Journal of Plant Biotechnology
• /
• 제36권4호
• /
• pp.392-396
• /
• 2009

Protocorms were newly formed from the culture of axillary buds, obtained in the seedlings of Dendrobium moniliforme in vitro. Its formation ratio was calculated to 43.7% on MS medium containing 1.0 mg/L BA. To test their survival ratio, we gradually increased the inoculation of transplant populations from single to more than three, and then found that the ratio in three populations went up as high as 95.2% rather than those of one or two. In bioreactor, explant obtained from the axillary bud grew well in lower concentration as 1/4 MS medium, while clearly grew slow in a little bit high concentration as 1/2 MS medium. We found that the explant of axillary bud, obtained from the Dendrobium moniliforme seedlings, would grow five times after culturing in a bioreactor for six weeks in 1/4 MS medium.

• 한국산림과학회지
• /
• 제95권5호
• /
• pp.585-590
• /
• 2006

In vitro-grown axillary shot-tip meristems of Lycium chinense Mill. from cold-acclimated plant were successfully cryopreserved using a vitrification technique. After loading for 15 minutes with a mixture of 2.0 M glycerol and 0.4 M sucrose ($20^{\circ}C$), small segments (1-2 mm, 3-4 mm, and 5-6 mm) were cut from axilary buds and exposed to the cryoprotectant solution containing 30% glycerol, 15% ethylen glycol,15% dimethyl sulfoxide (DMSO), and 0.4 M sucrose at $0^{\circ}C$ for 30-120 minutes prior to direct plunge into liquid nitrogen (LN). After rapid thawing ($40^{\circ}C$), the segments were washed with MS medium containing 1.2 M sucrose for 0-35 minutes, and then transferred onto recovery-growth medium. The highest survival rate (about 90%) was obtained with cold-hardening treatment, and cryopreserved explants were successfully recovered to plantlets. No abnormal morphological changes were observed with the recovered plants after cryopreservation.

• 한국식물학회:학술대회논문집
• /
• 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
• /
• pp.213-237
• /
• 1987

In vitro flowering system may minimize the confounded influence of non-floral meristem parts of plants in studying the relationship of a given treatment and flowering responses. We have induced flower buds from plantlets regenerated from zygotic embryo-derived somatic embryos of ginseng, which circumvented the normal 2-year juvenile period before flowering. The result suggests that the adulthood of ginseng root explants in the experiment previously conducted by Chang and Hsing (1980; Nature 284: 341-342) is not prerequired to flowering of plantlets regenerated through somatic embryogenesis. We have also induced flower buds from elongated axillary brandches from cotyledonary nodes by culturing ginseng zygotic embryos, seedlings, and excised cotyledonary nodes. It was found that 6-benzyladenine (BA) supplemented to the medium was essential for flowering, whereas abscisic acid (ABA) was inhibitory. Gibberellic acid(GA3) was also required for flowering when ABA was present with BA in the medium. The results suggest that cytokinins, gibberellins, and inhibitors play primary, permissive, and preventive roles, respective-ly, in the induction of flowering of ginseng. Tran Thanh Van (1980; Int. Rev. Cytol., Suppl. IIA: 175-194) has developed the "thin cell layer system" in which the induction of shoots, roots, or flower buds from epidermal layer explants were controlled by culture conditions and exogenous growth regulators in the medium, Utilizing the thin cell layer system, Meeks-Wagner et al. (1989; The Plant Cell 1: 25-35) have cloned genes specifically expressed during floral evocation. However, the system is too tedious for obtaining a sufficient amount of plant materials for biochmical and molecular biological studies of flowering. We have developed a garlic callus culture system and one obvious advantaging over the thin cell layer system is that an abundant cells committed to develope into flower buds proliferate. When the above cells were compared by two-dimensional gel electrophoresis with those which have just lost the competence for developing into flower buds, a few putative proteins specific to floral evocation were detected. The garlic callus culture system can be further explored for elucidation of the molecular biological mechanism of floral evocation and morphogenesis.hogenesis.

• Plant Biotechnology Reports
• /
• 제3권4호
• /
• pp.333-340
• /
• 2009

Developmental anomalies in the plumule meristem of peanut (Arachis hypogaea L.) somatic embryos resulted in poor shoot differentiation and reduced plant recovery. Existing meristems with caulogenic potential have never been tested for embryogenesis in peanut. The present experiment was designed to test the mature zygotic embryo axis derived plumule with three meristems for somatic embryogenesis. Embryogenic masses and embryos developed from the caulogenic meristems in the axils. Exposure of 2 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation temporarily which then regained the ability to form the shoot on withdrawal of 2,4-D. Exposure of 4 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation irreversibly. No shoot formation was noted from the tips in any of the cultures which were in secondary medium with $13.6{\mu}M$ 2,4-D. Development of somatic embryos directly from axillary meristems was confirmed histologically. Conversion frequency of these embryos was 11%. Thus, in this report, we describe a method to obtain somatic embryos from the determined organogenic buds of the axillary meristem, by culturing the nodal explant vertically on embryo induction medium. It also displays the possibility of obtaining both embryogenic and organogenic potential in two parts of the same explant simultaneously. The possibility of extending this approach for genetic transformation in in vivo system through direct DNA delivery or Agrobacterium injection in meristems can also be explored. Using Agrobacterium rhizogenes, we have demonstrated the possibility of gene transfer in the axillary meristems of seed-derived plumule explant.

• 한국자원식물학회지
• /
• 제19권3호
• /
• pp.385-391
• /
• 2006

In vitro-grown axillary buds of Melia aredarach were successfully cryopreserved by vitrification. On the MS medium supplemented with BA 1 mg/L, multiple shoots were developed within $4{\sim}5$ weeks. Plantlets of Melia azedarach were cold-hardened at $10^{\circ}C$ for a 16-hr photo-period for 6 weeks. Excised axillary shoot-tips from hardened plantlets were precultured on a solidified Murashige & Skoog agar medium (MS) supplemented with 0.7 M sucrose for 1 day at $25^{\circ}C$. Axillary shoot-tip meristems wert dehydrated using a highly concentrated vitrification solution (PVS2) for 60 min at $0^{\circ}C$ prior to a direct plunge into liquid nitrogen (LN). The PVS2 vitrification solution consisted of 30% glycerol (w/v), 15% ethylene glycol (w/v), 15% DMSO (w/v) in MS medium containing 0.4M sucrose. After short-term warming in a water bath at $40^{\circ}C$, the meristems were transferred into 2 ml of MS medium containing 1.2M sucrose for 15 min and then planted on solidified MS culture medium. Successfully vitrified and warmed meristems resumed growth within 2 weeks and directly developed shoots without intermediary callus formation. The survival rate of cold-hardened plantlets for 3 and 4 weeks was 90%. We did not find any difference in PCR-band patterns between control and cryopreserved plants. This method appears to be a promising technique for cryopreserving axillary shoot-tips from in vitro-grown plantlets of Medicinal plants.

• 식물조직배양학회지
• /
• 제24권6호
• /
• pp.357-360
• /
• 1997

쇠무릎(A. japonica) 다량증식 방법의 일환으로 액아를 이용한 multiple shoot유도를 위한 최적 조건을 조사하였다. 기내에서 증식하고 있는 식물체로부터 액아를 적출하여 NAA, 2,4-D 및 BA가 여러 농도로. 첨가된 MS 배지(3% sucrose, 0.2% gelrite)에서 6주 간 배양한 결과, shoot의 발생은 1mg/L NAA와 2mg/L BA가 첨가된 처리구에서 액아 당 평균 25.8개로 가장 많았다. 신초의 발생 빈도는 조금 낮지만 발생된 신초가 완전한 식물체로 되기 위한 크기를 고려할 때의 조합은 0.5 mg/L NAA와 1 mg/L BA가 첨가된 처리구에서 액아 당 19.7개의 신초가 발생하여 가장 좋은 결과를 얻었다. 한편 발생된 신초는 절취하여 0.1mg/L IBA가 첨가된 1/2 MS 배지에서 배양했을 때 뿌리의 발생과 신장이 가장 양호하였으며, 식물체의 생육도 왕성하였다. 발근된 식물체를 기외로 이식 후 활착시켜 쇠무릎의 액아 배양을 통한 다량증식의 가능성을 확인하였다.

• Journal of Plant Biotechnology
• /
• 제37권1호
• /
• pp.110-114
• /
• 2010

조직배양 감자줄기를 1/3 MS 액체배지가 첨가된 18 L 바이오리액터 배양기에서 배양하였을 때 생중량 증식이 가장 양호하였고, 1/4 MS 액체배지, 1/2 MS 액체배지 순으로 감자줄기의 생중량이 증가하였다. 감자 소괴경 형성은 감자줄기를 배양한 바이오리액터에서 배지를 따라 내고, 소괴경 형성용 배지로 교환하여 어두운 곳에서 암배양하면 소괴경이 형성되었다. 소괴경은 암배양 1주후부터 줄기 마디의 측아에서 생성되기 시작하여 3주 정도에 대부분이 형성되고 1.5 MS 액체배지와 $20^{\circ}C$ 온도 조건이 최적이었다. 이 조건에서는 6주 정도 배양하면 18L 바이오리액터 배양기에서 1,000개 이상의 소괴경을 생산할 수 있었다. 어두운 배양조건에서 소괴경이 거의 성장하면 바이오리액터를 빛이 있는 조건으로 옮겨 1주정도 배양한 후 녹화된 소괴경를 수확하였다.

• 한국자원식물학회지
• /
• 제36권6호
• /
• pp.571-579
• /
• 2023

In this study, cryopreservation by droplet-vitrification was applied to pear (Pyrus spp.) germplasm. We focused on the development and assessment of various strategies for the selection of suitable tissue, osmoprotection, and dehydration. We also evaluated post-thaw recovery of cryopreserved explants by droplet-vitrification. Preferentially, we tested the effects of preculture and loading treatments to determine which tissues were more suitable, either the apical shoot tips or the axillary buds. Apical shoot tips showed the better regrowth rate than in vitro axillary buds. The most effective techniques for cryopreservation were as follows. Shoots from in vitro seedlings which had been cultured for about 5-6 weeks were cold-hardened at 4℃ for one week, excised shoot tips were precultured on liquid MS medium including 0.3 M sucrose for 31 hours and 0.7 M sucrose for 17 hours, osmoprotected in loading solution (LS) for 40 min, and then cryoprotected in dehydration solution (PVS3) for 90 min. In addition, we found that regrowth rates of explants on regrowth medium after exposure to liquid nitrogen (LN) were higher than those on MS medium. Results indicated that the highest regrowth percentage was 95.6% for 'Bartlett' cultivar and 68.9% for 'BaeYun No.3' cultivar. Consequently, apical shoot tips of two pear cultivars, 'Bartlett' (P. communis) and 'BaeYun No.3' (P. pyrifolia), were successfully cryopreserved by droplet-vitrification. Results of this study show that the enhanced droplet-vitrification method described in the present study could be used as an effective means for long-term storage of pear genetic resources.