• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.183-186
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• 1994

Somatic embryos derived from cell suspension cultures of rice were singly alginate-encapsulated to be used as artificial seeds. When placed on half strength MS solid medium,73% of the encapsulated somatic embryos were capable of germination Encapsulation per se did not affect the germination frequency of embryos. When incubated by wrapping with moistured non-sterile filter paper, 60% of the encapsulated somatic embryos germinated. However encapsulated zygotic embryos without endosperm showed a high germination frequency regardless of the sterility of the incubation conditions. The results suggest that a greater susceptibility of somatic embryos to contaminants is attributed to lower germination frequency of encapsulated somatic embryos in non-sterile conditions.

• Journal of Plant Biotechnology
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• v.50
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• pp.267-274
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• 2023

All studies on date palm somatic embryogenesis have focused on germination in the presence of light while neglecting germination in darkness, which mimics the germination process of zygotic embryos within seeds. To improve the date palm micropropagation protocol, we investigated the effects of light and darkness incubation on the germination of indirect date palm somatic embryos and their subsequent conversion into plantlets. Darkness incubation emerged as a pivotal factor in the germination of indirect date palm somatic embryos and their successful conversion into plantlets. Darkness incubation significantly decreased the time required for the conversion of indirect somatic embryos into plantlets, halving the duration from 24 weeks to only 12 weeks. The micropropagation protocol was modified, consolidating the previous two distinct stages of germination and elongation under light incubation into a single stage under darkness incubation. These findings modified the protocol and significantly reduced the overall duration of the date palm micropropagation protocol.

• Journal of Plant Biology
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• v.32 no.3
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• pp.145-150
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• 1989

Mature zygotic embryos dissected from ginseng(Panax ginseng C. A. Meyer) seeds were cultured on Murashige and Skoog's (MS) medium containing various concentrations of 2, 4-dichlorophenoxyacetic acid(2, 4-D) and kinetin. Somatic embryos were induced directly from cotyledonary tissue or from intervening callus. The induction frequency of somatic embryos was up to 55%. Upon transfer to half-strength MS medium supplemented with 1 mg/1 6-benzyladenine(BA) and 1 mg/1 GA3, most somatic embryos developed into plantlets. Over 50% of the plantlets flowered after 4 weeks of culture and then a few bore immature fruits in vitro. Therefore, it is suggested that the juvenility of the ginseng tissue which give rise to somatic embryos does not interfere with in vitro flowering of their regenerated plantlets.

• Korean Journal of Medicinal Crop Science
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• v.3 no.1
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• pp.50-55
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• 1995

This study was conducted to determine the optimum conditions for induction and different somatic of somatic embryos as well as germination of encapsulated and stored somatic embryos. Somatic embryos was better formed in 1/2X MS medium than full - strength MS medium. 0.1 to 1.0mg/lBA and kinetin promoted shoot differentiation of somatic embryos. Higher concentration tend to inhibit differentiation. IAA affect positively both root and shoot growth. In vitro germination of somatic embryos encapsulated with 2% alginate matrix containing 1/2 MS nutrient medium and $AgNO_3$ 5mg/l was 86%. Storage of somatic embryos was effecive at $5^{\circ}C$ but the germination rate decreased with longer storage period. RAPD analyses with plants regenerated from the somatic embryos showed DNA polymorphism, indicating abolition of primer binding site by point mutation, deletion, or insertion of certain sequences.

• Journal of Plant Biotechnology
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• v.48 no.1
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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 Plant Biotechnology
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• v.6 no.3
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• pp.193-197
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• 2004

In vitro multiplication of Curculigo orchioides was achieved by direct somatic embryogenesis in young leaf segments. Immature leaf segments of about 0.5 cm in length were cultured on MS medium supplemented with different concentrations of BAP (2-10 $\mu{M}$) or Kin (2-10 $\mu{M}$). Optimum response in terms of per cent cultures responding (89%) and the number of embryos per explant (16) were observed on MS medium supplemented with 8 $\mu$M BAP. The emergence of several somatic embryos on the adaxial side of the leaf segments was observed one month after the culture. Germinated somatic embryos were grown up to about 1.5 cm length before transferring to maturation medium. For maturation, the individual embryos were isolated and transferred to MS medium supplemented with BAP (5 $\mu{M}$) and NAA (0.5 $\mu{M}$). The plantlets emerged from the embryos were transferred to soil containing 1 peat: 1 sand with 90% success. The embryos were formed directly on the leaf segments without any callus phase. Direct regeneration of somatic embryos is important for the conservation of this endangered species, as rare somaclonal variants are likely to arise than from indirect regeneration.

• Journal of Ginseng Research
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• v.23 no.3 s.55
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• pp.130-134
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• 1999

Somatic embryos were induced directly from cotyledon explants of Korean ginseng (Panax ginseng C.A. Meyer) on Murashige and Skoog (MS) medium with 2,4-D, BAP, kinetin or lacking growth regulators. When somatic embryos formed on all media grew to cotyledonary stage, the further development of embryos was ceased and remained in white color. By gibberellic acid (over 1.0 mg/1 $GA_3$) treatment, all the somatic embryos turned rapidly to green and germinated within 3 weeks. Chilling treatment also induced the germination of somatic embryos. The effective temperature regime was $-2^{\circ}C$ for over 8 weeks but more higher temperature than $0^{\circ}C$ did not effective for germination of somatic embryos. Ultrastructural observation revealed that the cotyledon cells of somatic embryos without chilling or $GA_3$ treatment contained numerous lipid reserves, dense cytoplasm, proplastids and non-activated mitochondria with poorly differentiated internal structure, but the cotyledon cells of germinating somatic embryos after chilling or $GA_3$ treatment highly vacuolated and contained well-developed chloroplasts and active state of mitochondria enclosing numerous cristae. The above results indicate that in vitro developed somatic embryos of Panax ginseng may be dormant after mature similar to zygotic embryos.

• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.547-551
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• 2008

The study aimed to develop a cryopreservation method for long-term storage using mature somatic embryo of Japanese larch. In this study, desiccation treatments significantly affected re-induction rates of embryogenic tissue (ET) from dried somatic embryos. In the effect of different dehydration temperature and duration on the re-initiation ET. the highest frequency was shown when somatic embryos were dehydrated at $25^{\circ}C$ for 2 (45.5%) or 1 day (43.3%), respectively. In addition, low temperatures [$4^{\circ}C$, 2 days (44.2%) or 3 days (43.5%)] were marked higher ET initiation. After that, the initiation value was declined with dehydration duration. For comparison of different relative humidity on re-induction frequency of ET, the best re-induction (43.5%) was obtained from somatic embryos pre-dried at $(NH_4)_2SO_4$ (RH 79%). Both $Na_2HPO_4$ (RH 97%) and $Na_2CO_3$ (RH 88%) treatments were showed the similar rate, 34.6, 34.2%, respectively. However the lowest rate (19.6%) was observed in distilled water (RH 100%). In comparison of the various storage temperatures and duration of the dried somatic embryos, the highest frequency (66.9%) of re-initiation was obtained when somatic embryos were cryopreserved for one day. However, the frequency was gradually decreased as the time length of storage increased regardless of types of storage. None of ET re-initiated when stored at $4^{\circ}C$ for 1, 2 and 84 days.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.230-235
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• 2009

The effect of auxin transport inhibitor (TIBA and PCIB) or auxin synergist (phloroglucinol) on somatic embryo maturation and germination in Japanese larch (Larix leptolepis) was examined. The addition of 15.8 mg/L ABA+5.0 mg/L PCIB showed most promoted the maturation of cotyledon -staged somatic embryos (177.7/90 mg ESM). In contrast, with treatment of 5.0 mg/L PCIB or 5.0 mg/L TIBA, no somatic embryos were obtained. Considering from this result, PCIB or TIBA alone could not substitute for exogenously supplied ABA for maturation of somatic embryos. In the test of below concentration of 5.0 mg/L PCIB, the highest results were recorded in 15.8 mg/L ABA+2.0 mg/L PCIB (109.3/90 mg ESM) or 15.8 mg/L ABA+5.0 mg/L PCIB (103.7/90 mg ESM). However, 5.0 mg/L phloroglucinol (0/90 mg ESM) or no ABA addition (3/90 mg ESM) had little influence on somatic embryos maturation. In germination study, the highest frequency of plantlet regeneration obtained from the somatic embryos which had matured on 15.8 mg/L ABA+5.0 mg/L PCIB (67.9%). However, either 5.0 mg/L PCIB nor 5.0 mg/L TIBA resulted in obtained from plantlets.

• Korean Journal of Plant Resources
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• v.26 no.4
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• pp.511-515
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• 2013

Hypocotyls explants of melon seedling were cultured on Murashige and Skoog's (MS) medium supplemented with 1 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.5 mg/L benzyl aminopurine (BA) for 6 weeks to produce somatic embryos. In somatic embryos produced through intervening bright yellow friable (BYF) from the explants, somatic embryos with two-cotyledon (26%) and horn-type cotyledon (74%) were observed. The procambial strand of cotyledons was originated from circular procambial tissues of lower hypocotyls. The circular procambial independently divided into two procambial strand at the edge of cotyledonary-node, and then connected to each cotyledon to form somatic embryos with two-cotyledon. When cotyledon was horn-type, the circular procambial strand in lower hypocotyls would continuously remain connected to the cotyledon. However, somatic embryos with two or horn type cotyledon formed an abnormal shoot apex without the tunica-corpus structure or dome shape in the inter-cotyledonary area. These results demonstrated that the variation of cotyledon in somatic embryos was closely related to procambial tissue differentiation and shoot apical formation.