scholarly journals 028 SOMATIC EMBRYOGENESIS IN QUERCUS SPECIES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 431e-431
Author(s):  
Sudeep Vyapari ◽  
Houchang Khatamian

Somatic embryogenesis was successfully achieved in chinkapin oak (Quercus muehlenbergii Engelm.) and pin oak (Quercus palustris Muenchh.) when surface disinfested zygotic embryo explants were cultured on MS or WPM containing BA or kinetin (1.0 or 2.0 mg 1-1) plus IBA (1.0 mg 1-1). Immature embryos resulted in greater callus induction than the mature ones. Two weeks of dark, proved to be superior to 4 weeks or no dark in callus induction. Somatic embryos of pin oak distinctly showed globular, heart and cotyledonary stages. Maturation and germination of pin oak somatic embryos was done in growth regulator free WPM by increasing levels of agar (7 - 15 g 1-1). Somatic embryos cultured at various levels of agar were then maintained in incubator under standard conditions, desiccated by air-drying or subjected to chilling temperature for 4 weeks to enhance germination of somatic embryos. Root or shoot formation was observed in some cultures, and medium with 9 g 1-1 agar induced plantlet production in 7% of the cultures.

1970 ◽  
Vol 14 ◽  
pp. 31-38 ◽  
Author(s):  
M Rahman ◽  
M Asaduzzaman ◽  
N Nahar ◽  
MA Bari

Somatic embryos were obtained from cotyledon and midrib explants of Solanum melongena L., cultivar Loda. For callus induction, medium was supplemented with different concentrations of auxin singly or in combination with BAP. The best callusing 83-85% was obtained from both of the explants cultured on MS medium containing 2.0 mgl-1NAA + 0.05 mgl-1BAP. Somatic embryogenesis and shoot regeneration was achieved after transferring the calli to MS medium supplemented with BAP, GA3, NAA and Zeatin. Cotyledon derived calli showed better performance (87%) for regeneration than that of midrib (82%) when sub cultured on MS medium having 2.0 mgl-1 Zeatin + 1.0 mgl-1 BAP. For root induction, MS + 3.0 mgl-1 IBA was proved to be better treatment for average number (14-15) and mean length (12 cm) of roots than those of other treatments. Key words: Eggplant; cotyledon; midrib; callus induction; somatic embryo J. bio-sci. 14: 1-9, 2006


2020 ◽  
Vol 20 (4) ◽  
pp. 179 ◽  
Author(s):  
NUR AJIJAH

<p>ABSTRAK</p><p><br />Embriogenesis somatik kakao (Theobroma cacao L.) telah banyak<br />dilaporkan  dengan  penggunaan  zat  pengatur  tumbuh  (ZPT)  yang<br />bervariasi. Penggunaan thidiazuron untuk menginduksi embriogenesis<br />somatik kakao telah dilaporkan melalui dua tahap induksi kalus. Penelitian<br />ini bertujuan untuk mengevaluasi efektivitas thidiazuron menginduksi<br />embriogenesis somatik kakao melalui satu tahap induksi kalus. Penelitian<br />dilaksanakan di Laboratorium Kultur Jaringan Unit Pengembangan Benih<br />Unggul, Badan Litbang Pertanian, Bogor. Empat taraf thidiazuron (0; 2,5;<br />5,0; dan 10 µg/l) dikombinasikan dengan 2,4-D 2 mg/l<br />digunakan untuk<br />menginduksi kalus dan embrio somatik 3 klon kakao (TSH858, Sca6, dan<br />ICS13) menggunakan eksplan mahkota bunga dan staminoid. Media dasar<br />DKW tanpa ZPT digunakan sebagai kontrol. Penelitian disusun dalam<br />rancangan lingkungan acak lengkap dengan lima ulangan. Setiap unit<br />percobaan terdiri dari sepuluh eksplan. Peubah yang diamati meliputi<br />persentase pembentukan kalus umur 2 dan 4 minggu, penampakan visual<br />kalus, persentase eksplan membentuk embrio somatik, dan jumlah embrio<br />somatik per eksplan umur 10 dan 14 minggu. Kalus terbentuk pada media<br />dengan penambahan hanya 2,4-D atau 2,4-D + thidiazuron, namun embrio<br />somatik hanya terbentuk pada media dengan penambahan 2,4-D +<br />thidiazuron. Pembentukan kalus dan embrio somatik sangat dipengaruhi<br />oleh tipe eksplan dan genotipe. Klon Sca6 lebih responsif dibandingkan<br />TSH858 dan ICS13 dan eksplan staminoid lebih responsif dibandingkan<br />mahkota bunga. Hasil studi ini menunjukkan terdapat pengaruh interaksi<br />yang kuat antara ZPT, genotipe, dan tipe eksplan terhadap pembentukan<br />kalus dan embrio somatik kakao serta tidak terdapat perbedaan hasil yang<br />nyata antara pembentukan embrio somatik melalui satu dan dua tahap<br />induksi kalus.<br />Kata kunci: Theobroma cacao L., genotipe, eksplan, zat pengatur tumbuh</p><p>ABSTRACT</p><p><br />Somatic embryogenesis of cacao (Theobroma cacao L.) has been<br />widely reported with varied of plant growth regulators (PGR) used. The<br />use of thidiazuron in inducing somatic embryogenesis of cacao has been<br />reported through a two-step callus induction. The study aimed to evaluate<br />the effectiveness of thidiazuron in inducing somatic embryogenesis of<br />cacao through a one-step of callus induction. The study was conducted at<br />the tissue culture laboratory of Agricultural Seed Development Unit,<br />Indonesian Agency for Agricultural Research and Development, Bogor.<br />Four levels of thidiazuron (0; 2.5; 5.0; and 10 µg/l) in combination with 2<br />mg/l  2,4-D  were  used  for  inducing  callogenesis  and  somatic<br />embryogenesis of three cacao clones (TSH858, Sca6, and ICS13) using<br />petals and staminoids explants. DKW basal medium without PGR was<br />used as a control. The result showed that callus were formed on medium<br />containing only 2,4-D or 2,4-D + thidiazuron, while embryos were only<br />formed on medium containing 2,4-D + thidiazuron. The formation of<br />callus and somatic embryos were highly affected by explant types and<br />genotypes. Sca6 clone was more responsive than TSH858 and ICS13 and<br />staminoids were more responsive than petals. The results of this study<br />revealed that there was a strong interaction between the PGRs, genotypes,<br />and explant types on the formation of cacao callus and somatic embryos.<br />Results of this study also showed no significant difference between the<br />formation of somatic embryos through one and two steps of callus<br />induction.<br />Keywords: Theobroma cacao L., genotypes, explants, plant growth<br />regulators</p>


Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 3 ◽  
Author(s):  
Xiuxia Ren ◽  
Ya Liu ◽  
Byoung Ryong Jeong

Somatic embryogenesis is a preferred method for vegetative propagation due to its high propagation efficiency. In this study, zygotic embryos, cotyledons, and hypocotyls of Paeonia ostii ‘Fengdan’ were used as the explant to induce somatic embryogenesis. The results showed that a combination of 0.5 mg·L−1 thidiazuron (TDZ) and 0.5 mg·L−1 2,4-dichlorophenoxyacetic acid (2,4-D) was effective in inducing somatic embryos from the zygotic embryo and cotyledon explants. Hypocotyls only formed somatic embryos on Murashige and Skoog (MS) medium supplemented with both 0.5 mg·L−1 TDZ and 0.5 mg·L−1 1-naphthylacetic acid (NAA). Moreover, the compact callus was effectively produced from zygotic embryo, cotyledon, and hypocotyl explants in medium supplemented with a combination of 3.0 mg·L−1 6-benzylaminopurine (BA) and 1.0 mg·L−1 NAA, and then converted into somatic embryos in the same medium, and the ratio of the explants with embryo induction and number of embryos induced per explant were much higher than those induced by 0.5 mg·L−1 TDZ and either 0.5 mg·L−1 2,4-D or 0.5 mg·L−1 NAA. The MS medium was better than the woody plant medium (WPM) for inducing somatic embryos from zygotic embryo and hypocotyl explants, whereas the WPM was better than the MS medium for somatic embryogenesis induction from cotyledon explants. All of the somatic embryos developed well into mature embryos on their respective media supplemented with both 3.0 mg·L−1 BA and 1.0 mg·L−1 NAA. Overall, the protocols for indirect somatic embryogenesis from zygotic embryo, cotyledon, and hypocotyl of P. ostii ‘Fengdan’ were successfully established, which can greatly facilitate their propagation and breeding processes.


Development ◽  
1997 ◽  
Vol 124 (10) ◽  
pp. 2049-2062 ◽  
Author(s):  
E.D. Schmidt ◽  
F. Guzzo ◽  
M.A. Toonen ◽  
S.C. de Vries

The first somatic single cells of carrot hypocotyl explants having the competence to form embryos in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D) were identified using semi-automatic cell tracking. These competent cells are present as a small subpopulation of enlarged and vacuolated cells derived from cytoplasm-rich and rapidly proliferating non-embryogenic cells that originate from the provascular elements of the hypocotyl. A search for marker genes to monitor the transition of somatic into competent and embryogenic cells in established suspension cell cultures resulted in the identification of a gene transiently expressed in a small subpopulation of the same enlarged single cells that are formed during the initiation of the embryogenic cultures from hypocotyl explants. The predicted amino acid sequence and in vitro kinase assays show that this gene encodes a leucine-rich repeat containing receptor-like kinase protein, designated Somatic Embryogenesis Receptor-like Kinase (SERK). Somatic embryos formed from cells expressing a SERK promoter-luciferase reporter gene. During somatic embryogenesis, SERK expression ceased after the globular stage. In plants, SERK mRNA could only be detected transiently in the zygotic embryo up to the early globular stage but not in unpollinated flowers nor in any other plant tissue. These results suggest that somatic cells competent to form embryos and early globular somatic embryos share a highly specific signal transduction chain with the zygotic embryo from shortly after fertilization to the early globular embryo.


2014 ◽  
Vol 65 (1-2) ◽  
pp. 37-41 ◽  
Author(s):  
Maria G. Ostrolucká ◽  
Diana Krajmerová

For the initiation of somatic embryogenesis early cotyledonary stage of zygotic embryo explants (from 15th July until late August) was suitable. The highest frequency of differentiation of somatic embryos was obtained on cotyledons of zygotic embryos cultured on basal modified medium MS (with 1/2 concentration macronutrients) or WPM medium containing 500 mg•l<sup>-1</sup> glutamine, proline and casein hydrolysate and supplemented with 2,4-D (1,0-2,0 mg•l<sup>-1</sup>) and BAP (0,5-1,0 mg•l<sup>-1</sup>). The development of somatic embryos was direct and indirect and the process was continuous over a long period. Primary somatic embryos were able to produce secondary embryos. Repetitive somatic embryogenesis led to the proliferation of a large number of new somatic embryos on their cotyledons, hypocotyl or radicula. The process of embryo differentation is asynchronous - various stages of somatic embryos could be observed in embryogenic culture. A somatic embryo conversion was rare on tested media. Embryo germination occured on medium containing BAP (0,1 mg•l<sup>-1</sup>) or on medium with ABA and GA<sub>3</sub> (each 0,2 mg•l<sup>-1</sup>) after a previous culture on WPM medium without plant growth regulators supplemented with sorbitol (6%). The embryo germination occurred also on WPM medium with 0.2 mg•l<sup>-1</sup> BAP when cultures were mantained at 2<sup>o</sup>C for 4 weeks. Only 8 somatic embryos developed into plantlets. Their transplantation to <em>in vivo</em> conditions was unsuccessful.


HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1167d-1167 ◽  
Author(s):  
L.G. Buckley ◽  
E.T. Graham ◽  
R.N. Trigiano

Zygotic and somatic embryos are purported to follow similar developmental sequences, but few investigations have thoroughly compared the two processes. Developing pods of Cercis canadensis L. (redbud) were collected from trees on the Knoxville campus of the University of Tennessee once or twice per week from 28 March to 8 August 1991. At least 10 ovules/sample date were fixed in FAA to evaluate zygotic embryo ontogeny. A minimum of 40 ovules/sample date were aseptically excised and placed on SH medium supplemented with 9.0 μM 2,4-D and 5 mM ammonium ion to initate somatic embryogenesis. Zygotic and somatic embryos were prepared for histological examination using standard paraffin techniques. Somatic embryos developed primarily from cotyledons and epicotyls of zygotic embryos mat were cultured between 6 June and 19 July. Somatic and zygotic embryos were subtended by multiseriate suspensors and progressed through recognizable globular, cordate and cotyledonary stages of development. Cotyledon morphology was similar for both embryo types. However, many somatic embryos failed to differentiate dome-shaped shoot meristems exhibited by their zygotic counterparts.


2009 ◽  
Vol 61 (3) ◽  
pp. 413-418 ◽  
Author(s):  
Sladjana Jevremovic ◽  
Angelina Subotic ◽  
Milana Trifunovic ◽  
Marija Nikolic

A simple protocol has been developed for plant regeneration by somatic embryogenesis of Southern Adriatic iris (Iris pseudopallida Trinajstic), an endemic species of the Balkan Peninsula. Somatic embryogenesis was induced in zygotic embryo culture on media supplemented with 2,4-dichlorophenoxy acetic acid (2-10 mgL-1) as the sole plant growth regulator, where both embryogenic calli and somatic embryos were induced. Subsequent decrease of 2,4-D in the media promoted formation of somatic embryos. Developed somatic embryos germinated on medium without growth regulators. The regenerated plantlets had diploid chromosome number. Planted plantlets acclimatized very well under greenhouse and garden conditions.


2019 ◽  
Vol 49 (12) ◽  
pp. 1604-1612
Author(s):  
Tingyu Sun ◽  
Yanli Wang ◽  
Lihua Zhu ◽  
Xiaoqin Wu ◽  
Jianren Ye

Pine wilt disease (PWD) is a severe threat to pine forests in East Asia. Screening and breeding of resistant varieties is a very effective way to prevent and control PWD; however, no reliable somatic embryogenesis system has yet been developed for the elite nematode-resistant Pinus thunbergii Parl. line. In this study, we studied the plant regeneration via somatic embryogenesis of nematode-resistant P. thunbergii. Initiation of embryogenic tissue was significantly affected by seed family (p = 0.017), immature zygotic embryo stage (p = 0.032), and initiation medium (p = 0.004). Seed family 37 was the most favorable female parent for initiation of P. thunbergii. Furthermore, the initiation rate increased from the pre-embryonic stage to the cleavage polyembryonic stage. The optimal medium was I2, containing 2,4-dichlorophenoxyacetic acid (9 μmol·L−1) and 6-benzyladenine (4.4 μmol·L−1). A statistically significant interaction between cell line and subculture time (24 months) was observed in the influence on proliferation rate, somatic embryo production, and percentage germination (p < 0.001). In this study, the highest somatic embryo production was achieved using cell line 37-1 (1983 somatic embryos per gram fresh mass), with approximately 83.5% of somatic embryos germinating after transferring to germination medium, of which 77.6% converted into plantlets.


2021 ◽  
Author(s):  
Thiago Sanches Ornellas ◽  
Yohan Fritsche ◽  
Edison Cardona Medina ◽  
Miguel Pedro Guerra

Abstract Bamboos are an important worldwide non-timber forest product with current rising interest due to their environmentally friendly applications. Besides the consolidated uses of the sweet shoots and culms for structural uses, Dendrocalamus asper is an imposing ornamental bamboo for horticulture. The present work aimed to establish in vitro calli culture and plant regeneration through somatic embryogenesis starting from young inflorescences of the giant bamboo, D. asper. Pre-anthesis inflorescences were collected, disinfested, and subjected to callus induction on MS basal medium supplemented by 0 µM, 9 µM, 18 µM, 27 µM, and 36 µM of 2,4-D in combination with 9 µM of 2-iP or 9 µM Kin. The different obtained calli types were characterized and subcultured in 0 µM, 4.5 µM, 9 µM, and 18 µM of 2,4-D in combination with 9 µM of both cytokinins for multiplication and differentiation. Additionally, the explant incision and its inoculation orientation onto culture media were tested for callus induction improvement. The 2,4-D was essential for callus induction, and its combination with both cytokinins resulted in embryogenic callus induction and further somatic embryos regeneration. The subsequent reduction of this auxin to 4.5 µM resulted in somatic embryo maturation. Somatic embryos transferred to a plant growth regulator-free medium resulted in plantlet conversion. The present work showed the feasibility of using inflorescences as explants and the efficiency of using the 2-iP in combination with 2,4-D to callus induction and in vitro bamboo plant regeneration through somatic embryogenesis.


HortScience ◽  
1995 ◽  
Vol 30 (6) ◽  
pp. 1295-1297 ◽  
Author(s):  
Carol Gonsalves ◽  
Baodi Xue ◽  
Dennis Gonsalves

Six summer squash (Cucurbita pepo L.) cultivars were regenerated via somatic embryogenesis using cotyledons excised from germinated or nongerminated seeds. Genotypes included were zucchini, commercial F1 hybrids, `President', `Seneca Zucchini', `Jade'; the noncommercial inbred line `Caserta Inbred 557311'; and two yellow squash hybrids `Dixie' and `Seneca Butterbar'. Somatic embryogenesis was initiated in induction medium containing 22.62 μm 2, 4-D, and embryos were germinated in maturation medium containing 0.27 μm NAA and 0.23 μm kinetin. Plants were elongated and rooted on basal medium without hormones. All media contained carbenicillin at 500 mg·liter–1. Sixty-one percent of the `Seneca Butterbar' cotyledons produced somatic embryos when kept on induction medium for 10 weeks. Overall, 7% of the initial explants produced plantlets, and regeneration efficiency was calculated as 0.3 plantlets per initial explant. The relative production of plants from cotyledons that were kept on induction medium for different time periods were determined for `Caserta Inbred 557311' and `Seneca Zucchini'. All cotyledons produced somatic embryos after 11 to 17 weeks on induction medium. However, plantlet production was optimal with explants kept on induction medium for 13 weeks for `Seneca Zucchini' and for 15 weeks for `Caserta Inbred 557311', producing an average of 4.5 and 9.3 plants per explant, respectively, from 90% to 70% of the explants. We recovered plants from all six cultivars; thus, our regeneration protocol may be applicable to other genotypes. The high percentage of regenerants obtained indicates that the regeneration method is efficient enough to be adapted successfully to squash transformation experiments. Chemical names used: α-carboxybenzylpenicillin (carbenicillin); 2,4-dichlorophenoxyacetic acid (2,4-D); 6-furfurylaminopurine (kinetin); α-napthaleneacetic acid (NAA).


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