Duration of Treatment of Carrot Hypocotyl Explants with 2,4-Dichlorophenoxyacetic Acid for Direct Somatic Embryogenesis

1996 ◽  
Vol 60 (5) ◽  
pp. 891-892 ◽  
Author(s):  
Yoshihiko Tokuji ◽  
Hiroshi Masuda
1989 ◽  
Vol 19 (2) ◽  
pp. 285-288 ◽  
Author(s):  
S. A. Merkle ◽  
A. T. Wiecko

Tissue cultures were initiated from developing seeds of black locust (Robiniapseudoacacia L.) collected from three trees at weekly intervals from 1 week following anthesis until early fruit maturity. Explants were cultured on media containing 0, 2, or 4 mg/L 2,4-dichlorophenoxyacetic acid and 0 or 0.25 mg/L 6-benzyladenine. Seeds explanted onto hormone-supplemented media remained on these media for 1 or 3 weeks before being placed on hormone-free media, or were maintained on hormone-supplemented media for the entire study. Direct somatic embryogenesis was observed in a single culture, initiated from a seed collected 4 weeks after anthesis and cultured for 1 week on a medium supplemented with 4 mg/L 2,4-dichlorophenoxyacetic acid and 0.25 mg/L 6-benzyladenine before transfer to basal medium. Although it could not be discerned from which part of the explant somatic embryos were derived, secondary embryogenesis continued from the radicles of cotyledonary-stage somatic embryos. Most somatic embryos were well formed, with two distinct cotyledons. Embryos germinated precociously, producing plantlets that were initially weak but later gained vigor and resembled seedlings.


HortScience ◽  
2006 ◽  
Vol 41 (5) ◽  
pp. 1325-1329 ◽  
Author(s):  
Martín Mata-Rosas ◽  
Ángel Jiménez-Rodríguez ◽  
Victor M. Chávez-Avila

Plants of Magnolia dealbata were regenerated from zygotic embryos through somatic embryogenesis and direct organogenesis. Medium and incubation conditions were determinating factors for the development of morphogenetic responses. Photoperiodic exposure was a limiting factor in the general development of the explants, and incubation in darkness allowed their development. The highest formation of shoots per responding explant were obtained on woody plant (WP) medium supplemented with 13.3 μM or 22.2 μM 6-benzylaminopurine (BA) in combination with 2.26 μM or in absence of 2,4-dichlorophenoxyacetic acid (2,4-D) from which 2.5 shoots per explant were induced. Subcultures on WP medium, supplemented with polyvinylpyrrolidone (PUP) 40,000 1 g·L–1) avoided necrosis of explants. Somatic embryos were formed in 85% of explants cultivated on WP medium with 2,4-D (2.3 μM or 4.5 μM); 20% induced indirect embryogenesis and 65% formed direct somatic embryogenesis. The plants were transferred to soil to acclimatize under greenhouse conditions, achieving 90% survival. Somatic embryo conversion to plantlets was obtained with subculture on WP basal medium without growth regulators. In vitro culture can play a key role in the propagation and conservation of this endangered species.


HortScience ◽  
1990 ◽  
Vol 25 (7) ◽  
pp. 792-793 ◽  
Author(s):  
Paula P. Chee

A simple procedure for regeneration of cucumber plants (Cucumis sativus L. cv. Poinsett 76) from cotyledon and hypocotyl explants has been developed. Somatic embryogenesis was induced on Murashige and Skoog (MS) salts and vitamins medium supplemented with 2,4-D at 2.0 mg·liter-1 and kinetin at 0.5 mg·liter-1. Development of embryos was accomplished on MS medium with NAA at 1.0 mg·liter-1 and kinetin at 0.5 mg·liter-1. Eighty-five percent of the mature somatic embryos formed showed a typical bipolar structure. All developed into morphologically normal plantlets when transferred to MS medium containing no growth regulators. Chemical name used: 2,4-dichlorophenoxyacetic acid (2,4-D).


HortScience ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Nancy Santana-Buzzy ◽  
Guadalupe López-Puc ◽  
Adriana Canto-Flick ◽  
Felipe Barredo-Pool ◽  
Eduardo Balam-Uc ◽  
...  

The ontogenesis of direct high-frequency somatic embryogenesis of C. chinense induced from hypocotyl was characterized through a histological analysis of the different phases in the histodifferentiation process during the development of the somatic embryo. The anatomical analysis was carried out since the hypocotyl segments were placed in the culture medium until 45 days of culture. The somatic embryos were induced and maintained in Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid (9.5 μm). Samples of tissues and organs were taken every 24 h, fixed in formalin acetic alcohol, and embedded in plastic resin. They were cut into serial sections (5 μm) and stained with toluidine blue. The analysis revealed that the proembryogenic cells originated just from provascular hypocotyl cells. Provascular cells acquired the embryogenic competence 48 h after induction and an intense mitotic division was observed and embryogenic structures were generated first along the vascular strands, which subsequently evolved into somatic embryos. After 2 weeks, there were observed embryos at different stages of development (preglobular, globular, heart-shaped, torpedo-shaped, and cotyledonary). This is the first report dealing with the ontogenesis of the direct somatic embryogenesis of C. chinense, and it is the most complete histological characterization carried out on somatic embryogenesis in the Capsicum genus to date.


2001 ◽  
Vol 49 (6) ◽  
pp. 753 ◽  
Author(s):  
T. Radhakrishnan ◽  
T. G. K. Murthy ◽  
K. Chandran ◽  
A. Bandyopadhyay

Direct somatic embryogenesis is an efficient method of plant regeneration, allowing rapid multiplication of plants in a short period. Six experiments were conducted to study the influence of auxin level on somatic embryogenesis and to optimise the concentration of auxins. Immature embryo axis was the ideal explant and 20–40 mg L–1 of 2,4-dichlorophenoxyacetic acid was the best concentration range for obtaining the maximum number of free somatic embryos. Significant differences were observed between the genotypes for induction and the number of somatic embryos per explant. The cv. Girnar 1 produced the maximum number of somatic embryos per explant, the number of secondary somatic embryos ranging from 1.5 to 9.4. The overall germination of somatic embryos was 42.8%, and 65% of the plantlets transferred to the field survived. The development of somatic embryos was from the apical region of the embryo axes without undergoing dedifferentiation. The initial cell divided to form a tier of four cells and subsequent anticlinal and periclinal division resulted in the development of globular somatic embryos with small suspensors, followed by heart-shaped, torpedo-shaped and ‘cotyledonary’ stages.


1984 ◽  
Vol 62 (6) ◽  
pp. 1245-1249 ◽  
Author(s):  
L. S. Kott ◽  
K. J. Kasha

Somatic embryogenesis was induced in callus previously initiated from immature embryos of barley. These cultures ranged in age from 6 weeks to 30 months. Embryoids were readily initiated from homogenized suspension-grown aggregates when plated on modified B5 media with 2,4-dichlorophenoxyacetic acid. Low concentrations (0.1 and 0.05 mg∙L−1) of abscisic acid promoted further maturation of embryoids, while gibberellic acid (1 mg∙L−1) and kinetin (0.1 mg∙L−1) were used in the media to encourage embryoid germination. The development of somatic embryoids from initiation through maturation and germination is described.


1996 ◽  
Vol 44 (4) ◽  
pp. 387-396 ◽  
Author(s):  
Perumal Venkatachalam ◽  
Narayanasamypillai Jayabalan

High yields of protoplasts were obtained from immature leaves of aseptically grown plants of Arachis hypogaea using an enzyme solution containing cellulase 2.0% (w/v) and Macerozyme 1.0% (w/v) in 0.6 M mannitol. Isolated protoplasts were cultured in Kao's medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP). The protoplasts started to divide after 3–5 days of culture. Sustained divisions resulted in mass production of cell colonies and mini calli in 4 weeks. After 4 weeks, protoplast colonies were transferred to the Murashige and Skoog (MS) medium supplemented with a-naphthalene acetic acid (NAA) and BAP. Colonies proliferated into actively growing calli. Further attempts to regenerate plants from such calli were not successful. However, protoclones differentiated roots on the same medium. Alternative methods for plant regeneration from protoplast derived callus cultures were tried through somatic embryogenesis. Protoplast-derived calli treated with 2,4-D and BAP formed somatic embryos. Somatic embryogenesis began in the proembryo stage and proceeded from globular to dicotyledonary stage. Embryos were then transferred onto hormone-free MS medium for germination. Five to ten percent of these embryoids germinated and grew to plantlets. Regenerated plants were transferred to plastic cups and grown to maturity.


1995 ◽  
Vol 43 (4) ◽  
pp. 385-390 ◽  
Author(s):  
S. Kulothungan ◽  
A. Ganapathi ◽  
A. Shajahan ◽  
K. Kathiravan

Embryogenic callus was induced from seedling leaf explants of cowpea (Vigna unguiculata (L.) Walp. cv. C152 on Murashige and Skoog (MS) medium containing 2.0 mg 1−1 2,4-dichlorophenoxyacetic acid (2,4-D). The maximum frequency of somatic embryogenesis was noticed when this callus was transferred to MS liquid medium supplemented with 2 mg 1−1 2,4-D. Further studies on ontogeny of somatic embryos showed that the cells destined to become somatic embryos divided into spherical or filamentous proembryos. Subsequent divisions in the proembryo led to globular, heart, torpedo-shaped, and cotyledonary-stage somatic embryos. Tiny plantlets were obtained by transferring the cotyledonary-stage somatic embryos to MS liquid medium containing 0.5 mg 1−1 2,4-D.


2013 ◽  
Vol 8 (6) ◽  
pp. 591-599 ◽  
Author(s):  
Agata Ptak ◽  
Anna Tahchy ◽  
Edyta Skrzypek ◽  
Tomasz Wójtowicz ◽  
Dominique Laurain-Mattar

AbstractIn vitro cultures of Leucojum aestivum are considered as an alternative for the production of galanthamine, which is used for the symptomatic treatment of Alzheimer’s disease. We studied the effects of auxins 2,4-dichlorophenoxyacetic acid (2,4-D), 4-amino-3,5,6-trichloropicolinic acid (picloram), 3,6-dichloro-o-anisic acid (dicamba) at concentrations of 25 and 50 µM on the induction of embryogenic callus and its capacity to induce somatic embryogenesis and alkaloid accumulation. The embryogenic response of the explants was from 30% for 25 µM of dicamba to 100% for picloram (for both 25 and 50 µM). 2,4-D (50 µM) stimulated greater callus proliferation and somatic embryo induction as compared to the other auxins. Polyethylene glycol (PEG) stimulated somatic embryo maturation. Callus grown on media containing 50 µM of auxins produced fewer phenolic compounds as compared with callus grown on media containing 25 µM of auxins. GC-MS analyses showed seven alkaloids in the in vivo bulbs and two to four in callus culture. Galanthamine was detected in callus cultivated with 2,4-D (25, 50 µM), picloram (25 µM), and dicamba (50 µM). Other alkaloids, trisphaeridine, tazettine, and 11-hydroxyvittatine were accumulated only in callus growing on medium with picloram (50 µM).


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