Somatic embryogenesis in mature zygotic embryos of Picea likiangensis

Biologia ◽  
2010 ◽  
Vol 65 (5) ◽  
Author(s):  
Shaoyu Chen ◽  
Shanna Chen ◽  
Fang Chen ◽  
Tao Wu ◽  
Yinbin Wang ◽  
...  

AbstractSomatic embryogenesis (SE) was successfully induced from mature zygotic embryos of seven families of Picea likiangensis (Franch.) Pritz after 20 weeks culture on initiation medium. Three basal media (one-half strength LM medium, one-half strength LP medium and improved LP medium) with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (6-BA) were tested but only one-half strength LM medium supplemented with 2,4-D and 6-BA was successful for the embryogenic cultures (EC) initiation. The initiation frequencies of EC varied greatly from different families when culturing on the same initiation medium. The highest frequency (41.3%) was induced from one of the families on one-half strength LM medium supplemented with 3 mg L−1 2,4-D and 1.5 mg L−1 6-BA and 16.83% on average for seven families. EC were subcultured and proliferated on the same medium as the initiation one every 10 days. 3 lines of EC induced from the same family were applied in maturation experiment. Cotyledonary somatic embryos were observed after EC were transferred to maturation media of one-half strength LM medium containing 20-80 mg L−1 abscisic acid and 7.5% polyethylene glycol (PEG-4000). However, one-half strength LM medium supplemented with 40 mg L−1 or 60 mg L−1 ABA and 7.5% PEG gave the best maturation and the 3 lines showed different ability in maturation. Over 80% cotyledonary somatic embryos germinated normally on DCR medium containing 0.2% activated carbon. The success on SE induction of the species has provided an effective clonal propagation method for this important tree’s genetic improvement.

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Premananda Das

Somatic embryogenesis was achieved in four leguminous tree species, that is, Acacia catechu, Acacia arabica, Hardwickia binata, and Dalbergia sissoo using immature zygotic embryos as explants on Murashige and Skoog (MS) medium supplemented with 0.25–1.0 mg/l Kn (kinetin) and 2.0–3.0 mg/l 2,4-D (2,4-dichlorophenoxyacetic acid) or NAA (1-napthaleneacetic acid) and 3% sucrose. MS medium containing 2.0 mg/l 2,4-D and 1.0–1.5 mg/l Kn was noted to be most effective in inducing friable embryogenic callus (FEC); the number of somatic embryos per culture varied in MS medium supplemented with 1.0–2.0 mg/l 2,4-D or NAA and 0.25–1.5 mg/l kinetin. The maximum number of somatic embryos was obtained in MS medium containing 1.5–2.0 mg/l 2,4-D or NAA and 1.0–1.5 mg/l kinetin; proliferation of embryogenic calli was enhanced in cultures having 1.0–2.0 mg/l 2,4-D, 1.0–1.5 mg/l kinetin, and 400–600 mg/l L-Proline. The somatic embryos in various shapes and sizes after the first subculture on MS medium supplemented with 0.1 mg/l IAA and 0.25 mg/l BA; developed shoots and rooted in strength MS medium supplemented with 0.1 mg/l IBA or IAA. The somatic embryo-derived plantlets were transferred to the field after being hardened in the climate-controlled hardening chamber.


2001 ◽  
Vol 44 (3) ◽  
pp. 247-255 ◽  
Author(s):  
Juliana A. Fernando ◽  
Murilo Melo ◽  
Marli K. M. Soares ◽  
Beatriz Appezzato-da-Glória

Mature zygotic embryos of Carica papaya L. ‘Sunrise Solo’ were used as explants for embryogenesis induction. The explants were inoculated on Murashige and Skoog culture medium supplemented with 2 mg.L-1 2,4-dichlorophenoxyacetic acid and incubated in darkness at 25+2°C. Histological analysis of callogenesis and somatic embryogenesis indicated occurrence of direct and indirect somatic embryogenesis development. Direct somatic embryo formation was observed from hypocotyledonary epidermic cells only from explant 18 days after inoculation. Somatic embryos formed indirectly were originated from embryogenic superficial cells of pre-embryonic complexes located on peripherical and on internal cell layers of callus 49 days after inoculation. Diverse morphological differences including disformed embryos were observed among the somatic embryos.


Author(s):  
Helena Vlašínová ◽  
Ladislav Havel ◽  
Marek Klemš ◽  
Stanislav Procházka

Uptake and metabolism of 2,4-dichlorophenoxyacetic acid (2,4-D) into zygotic embryos of Norway spruce (Picea abies (L.) Karst.) were studied on medium used for induction of somatic embryogenesis. The main task of this work was to study effect of longitudinal bisection of embryos, which was found as increasing the subsequent induction of embryogenic cultures. The maximal uptake of 2,4-D per one embryo was detected after 16 hours on medium in bisected embryos. The bisection increased 2,4-D uptake per embryo in first 16th hours, but then increased its release back to the medium. The metabolism of 2,4-D in bisected embryos was lower than in intact ones during first two days of culture.


2007 ◽  
Vol 59 (3) ◽  
pp. 199-202 ◽  
Author(s):  
Dragana Stojicic ◽  
Branka Uzelac ◽  
Dusica Janosevic ◽  
Ljubinka Culafic ◽  
Snezana Budimir

The potential for somatic embryogenesis in zygotic embryo and megagametophyte cultures of Pinus heldreichii was examined. Somatic embryogenesis was initiated from megagametophytes containing immature zygotic embryos at early stages of development. An induction frequency of up to 6.7% was obtained on Gresshoff and Doy medium in the presence of 2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/l benzyladenine (BA). Formation and further proliferation of embryogenic tissue were achieved upon transfer of explants to a medium with reduced levels of growth regulators. Somatic embryos are being cultured for further development. .


1990 ◽  
Vol 68 (2) ◽  
pp. 236-242 ◽  
Author(s):  
F. M. Tremblay

White spruce (Picea glauca) embryogenic callus was obtained using 3- to 11-year-old seeds as a source of zygotic embryos. They were cultured on half-strength Litvay's medium supplemented with 10 μM 2,4-dichlorophenoxyacetic acid, 5 μM benzylaminopurine, 1 g/L casein hydrolysate, 500 mg/L glutamine, and 1% sucrose. The frequency of induction of embryogenic callus was significantly improved by incubation at 25 °C and by a 4-h imbibition of the seeds. The yield of embryogenic callus was significantly affected by the geographic provenance of the seeds and by their number of years in storage. A significant correlation was also found between the yield of embryogénie callus and the percentage of germination of the seedlot used. Even after 11 years of storage, 40% of the zygotic embryos could produce an embryogenic callus when dissected from seeds with a high germination rate. Somatic embryos were matured after transfer onto an embryo development medium composed of the same medium but including 6% sucrose, 1 μM 2,4-dichlorophenoxyacetic acid, and 5 μM kinetin. The somatic embryos developed further under in vitro conditions and were then transplanted into soil. The somatic embryoderived plantlets established in the greenhouse were similar to control plantlets obtained from germinated seeds. Mature embryos from stored seeds were shown to constitute a valuable source for white spruce somatic embryogenesis.


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.


1997 ◽  
Vol 75 (3) ◽  
pp. 509-512 ◽  
Author(s):  
P. V. Bozhkov ◽  
I. S. Ahn ◽  
Y. G. Park

Individual mature stored seeds of Pinus koraiensis sometimes contain several viable zygotic embryos originated through the processes of simple and cleavage polyembryony. To induce the embryonic process, isolated zygotic embryos were cultured on five different media all supplemented with 10 μM 2,4-dichlorophenoxyacetic acid and 5 μM 6-benzyladenine. Two alternative pathways of somatic embryo origin were revealed. The first pathway was associated with the production of a friable, translucent callus in the hypocotyls–cotyledon region of the dominant zygotic embryo. The second pathway was related to the proliferation of a translucent, moist, and mucilaginous tissue (termed embryonal–suspensor mass) in the suspensor region of the dominant zygotic embryo. Both types of tissues contained early somatic embryos. Regression analysis has shown a strong negative correlation between the frequencies of formation of embryogenic callus and embryonal–suspensor mass both at 3 and 8 weeks of culture (r = − 0.85; p = 0.07 and r = −0.71; p = 0.17, respectively). Key words: Pinus koraiensis; polyembryonal seeds; somatic embryogenesis; embryogénie callus; embryonal–suspensor mass.


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.


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.


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