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1.
Maria Ludovina S. Guimarães Gil S. Cruz João M. Montezuma-De-Carvalho 《Plant Cell, Tissue and Organ Culture》1988,15(2):161-167
Callus cultures with globular proembryogenic structures were induced from zygotic embryos and hypocotyl segments of Cyphomandra betacea on MS medium supplemented with 2,4-D. Proembryogenic structures produced somatic embryos and plantlets on regulator-free basal medium. Pieces of embryogenic callus subcultured on medium with the same original composition gave rise to new globular structures and the potential for plantlet regeneration has been maintained for over a year. The histological examination of these proembryogenic structures suggested that somatic embryos arise from single cells. Regenerated plants are phenotypically normal, having diploid chromosome numbers (2n = 24). 相似文献
2.
P. Giridhar Vinod Kumar G. A. Ravishankar 《In vitro cellular & developmental biology. Plant》2004,40(6):567-571
Summary A novel protocol has been developed for inducing somatic embryogenesis from leaf cultures of Decalepis hamiltonii. Callus was obtained from leaf sections in Murashige and Skoog (MS) medium supplemented with α-naphthaleneacetic acid (NAA)+N6-benzyladenine (BA) or 2,4-dichlorophenoxyacetic acid (2,4-D)+BA. Nodular embryogenic callus developed from the cut end of
explants on media containing 2,4-D and BA, whereas compact callus developed on media containing NAA and BA. Upon subsequent
transfer of explants with primary callus onto MS media containing zeatin and/or gibberellic acid (GA3) and BA, treatment with zeatin (13.68μM) and BA (10.65 μM) resulted in the induction of the highest number of somatic embryos directly from nodular tissue. The maturation of embryos
took place along with the induction on the same medium. Embryogenic calluses with somatic embryos were subcultured onto MS
basal medium supplemented with 4.56μM zeatin+10.65 μM BA. After 4wk, more extensive differentiation of somatic embryos was observed. The mature embryos developed into complete
plantlets on growth regulator-free MS medium. A distinct feature of this study is the induction of somatic embryogenesis from
leaf explants of Decalepis hamiltonii, which has not been reported previously. By using this protocol, complete plantlets could be regenerated through indirect
somatic embryogenesis or organogenesis from leaf explants in 12–16 wk. 相似文献
3.
Embryogenic callus was obtained from bulb segments of Iris
pseudacorus on Murashige and Skoog (MS) medium with 2,4-dichlorophenoxyacetic acid (2,4-D) alone or in combination with kinetin. When
early globular somatic embryos were subcultured onto MS medium with 4.52 μM 2,4-D, high frequency of somatic embryogenesis
was obtained. Deprivation of 2,4-D was required for maturation. Mature somatic embryos had an elongated scutellum with a notch
on the base of scutellum. Separation of embryos from embryo clusters was necessary to enhance the frequency of germination.
Germination was stimulated by separation of embryos from embryo clusters and transfer onto fresh half-strength MS medium with
3% sucrose. After acclimation in artificial soil in greenhouse for 2 months, 96.4% of plantlets survived. 相似文献
4.
Summary
In vitro propagation of Andrographis paniculata (Burm. f.) Wallich ex Nees through somatic embryogenesis, and influence of 2,4-dichlorophenoxyacetic acid (2,4-1) on induction, maturation, and
conversion of somatic embryos were investigated. The concentration of 2,4-D in callus induction medium determined the induction,
efficacy of somatic embryogenesis, embryo maturation, and conversion. Friable callus initiated from leaf and internode explants
grown on Murashige and Skoog (MS) medium supplemented with 2.26, 4.52, 6.78, and 9.05μM 2,4-D started to form embryos at 135, 105, 150, and 185d, respectively, after explant establishment. Callus initiated at
13.56μM 2,4-D did not induce embryos even after 240 d, whereas those initiated on MS medium with 4.52μM 2,4-D was most favorable for the formation and maturation of somatic embryos. Callus subcultured on the medium with reduced
concentration of 2,4-D (2.26μM) became embryogenic. This embryogenic callus gave rise to the highest number of embryos (mean of 312 embryos) after being
transferred to half-strength MS basal liquid medium. The embryos were grown only up to the torpedo stage. A higher frequency
of embryos developed from callus initiated on 2.26 or 4.52 μM 2,4-D underwent maturation compared to that initiated on higher concentrations of 2.4-D. The addition of 11.7μM silver nitrate to half-strength MS liquid medium resulted in 71% of embryos undergoing maturation, while 83% of embryos developed
into plantlets after being transferred to agar inedium with 0.44 μMN6-benzyladenine and 1.44 μM gibberellic acid. Most plantlets (88%) survived under field conditions and were morphologically identical to the parent plant. 相似文献
5.
G. Vengadesan N. Selvaraj R. Prem Anand V. Gaba A. Ganapathi 《In vitro cellular & developmental biology. Plant》2005,41(6):789-793
Summary Suspension culture of cucumber (Cucumis sativus L.) has been an inefficient method for production of somatic embryos owing to problems with embryo maturation and conversion.
Embryogenic callus of cv. Green Long was induced on semisolid Murashige and Skoog (MS) medium containing 6.8 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.2 μM 6-benzylaminopurine (BA). A large number of globular somatic embryos were obtained on transfer of the callus to MS liquid
medium supplemented with 87.6 mM sucrose, 1.1 μM 2,4-D, and improved by the addition of 342.4 μM
l-glutamine. MS medium supplemented with 87.6 mM sucrose was more effective in somatic embryo production than other sugars. Subsequent development led to the formation of
heart-and torpedo-shaped embryos. Maturation of somatic embryos occurred on plant growth regulator-free MS semi-solid medium
containing 175.2 mM sucrose and 0.5 gl−1 activated charcoal. Conversion of embryos into plants was achieved on half-strength MS semi-solid medium containing 87.6
mM sucrose and 1.4 μM gibberellic acid (GA3) in a 16h photoperiod. Twenty-seven percent of embryos were converted into normal plants. 相似文献
6.
An efficient method of repetitive somatic embryogenesis and plant regeneration of two carnation cultivars (Sagres and Impulse)
was established using a two-step protocol. In the first step, embryogenic tissue were induced from petal explants on MS culture
medium containing 9% sucrose (w/v), 9 μM 2,4-D and 0.8 μM BA. In the second step, embryogenic tissue transferred onto the
MS medium containing 3% sucrose supplemented with different concentrations of picloram (0.8, 2, 4, 8 and 16 μM) to produce
primary somatic embryos. Precotyledonary clumps and cotyledonary somatic embryos were then isolated and subcultured onto the
same media as the second step where they formed secondary somatic embryos in repetitive cycles. Cotyledony somatic embryos
were converted into plantlets when they transferred onto the growth regulator-free half-strength MS medium followed by being
acclimated to the greenhouse conditions. 相似文献
7.
Piedad Gallego Oscar Hita Nieves Villalobos Ana Dorado Luisa Martin Hilario Guerra 《In vitro cellular & developmental biology. Plant》2001,37(2):199-203
Summary An efficient plant regeneration system employing cotyledons, hypocotyls, petioles and leaves as explants and characterized
by continuous and prolific production of somatic embryos, has been developed with Medicago arborea ssp. arborea. The optimal somatic embryogenic response was obtained using a two-step protocol, where explants were incubated under a 16
h photoperiod for 2 mo. on Murashige and Skoog (MS) medium containing 2,4-dichlorophenoxyacetic acid (2,4-D; 9 μM) and kinetin (9 μM), and followed by transfer to kinetin-free MS medium with 2,4-D (2.25 μM). Removal of the cytokinin and a reduction in the concentration of auxin (2.25 μM) in the second step of culture were critical for enhanced production of somatic embryos. The best explants proved to be cotyledons
and petioles (i.e. a mean of 18.0±0.70 somatic embryos at 3 mo. for petiole culture). Somatic embryos were converted into
normal plantlets (8.0±0.89%) when cultured on basal MS medium with 5 μM indolebutyric acid. No somatic embryos were obtained when thidiazuron was used in the culture media. Using petioles as explants
and N6-benzyladenine (BA), embryogenesis was induced in the second step of culture when BA was removed from the medium and the concentration
of 2,4-D was decreased to 2.25 μM. 相似文献
8.
By means of co-culture in growth regulator-free medium we analysed whether factors secreted into the medium of Daucus carota (carrot) somatic embryo cultures would be able to overcome the developmental arrest of globular Arabidopsis thaliana somatic embryos. Instead of Arabidopsis embryogenesis being promoted the development of carrot somatic embryos was inhibited at the globular stage in the presence
of Arabidopsis suspension culture aggregates with attached globular embryos. Several experiments showed that this was due to the release
of previously accumulated 2,4-D by the Arabidopsis cultures. (1) In addition to arresting carrot embryogenesis, co-culture with Arabidopsis cell suspensions also induced callus formation on Arabidopsis root segments. (2) Both effects only occurred with Arabidopsis suspensions grown in the presence of 2,4-D and not with those grown in the presence of NAA, demonstrating that Arabidopsis is not segregating a “general” inhibiting factor. (3) Both effects could be prevented by either binding 2,4-D to active charcoal
or by washing it away by changing the medium daily. (4) Uptake of 2,4-D into Arabidopsis cells during culture in 2,4-D containing medium and subsequent release of 2,4-D after transfer to growth regulator-free medium
was measured. (5) These low levels of released 2,4-D (0.2– 0.5 μm) could mimic the observed effects. Taken together these data suggest that the high intracellular 2,4-D content of Arabidopsis cultures may interfere with Arabidopsis somatic embryo development beyond the globular stage.
Received: 13 November 1997 / Revision received: 2 February 1998 / Accepted: 16 November 1998 相似文献
9.
Summary
In vitro regeneration of plants via somatic embryogenesis through cell suspension culture was achieved in horsegram. Embryogenic calluses
were induced on leaf segments on solid Murashige and Skoog (MS) medium with 9.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Differentiation of somatic embryos occurred when the embryogenic calluses were transferred
to liquid MS medium containing 2,4-D. Maximum frequency (33.2%) of somatic embryos was observed on MS medium supplemented
with 7.9 μM 2,4-D. Cotyledonary-torpedo-shaped embryos were transferred to liquid MS medium without growth regulators for maturation
and germination. About 5% of the embryos germinated into plants, which grew further on solid MS medium. The plants were hardened
and established in soil. Effects of various auxins, cytokinins, carbohydrates, amino acids, and other additives on induction
and germination of somatic embryos were also studied. A medium supplemented with 7.9 μM 2,4-D, 3.0% sucrose, 40 mg l−1
L-glutamine, and 1.0 μM abscisic acid was effective to achieve a high frequency of somatic embryo induction, maturation, and further development. 相似文献
10.
Rapid multiplication of adventitious somatic embryos in peach and nectarine by secondary embryogenesis 总被引:6,自引:0,他引:6
Somatic embryos were multiplied by secondary embryogenesis in cotyledonary cultures of peach and nectarine (Prunus persica L.) using a simplified culture medium for immature seeds. A three-stage process with an initial callus phase was established in darkness on a medium containing basal salts (modified MS) supplemented with 2,4-D (5 mg/l), Kn (2 mg/l) and BAP (2 mg/l) and casein hydrolysate (500 mg/l). This was followed by a growth regulator-free medium with activated charcoal for the adventitious and direct multiplication of somatic embryos under continuous light. Somatic embryos (10–15) originated from the epidermal layer of primary somatic embryos of 4–6 mm size. The incidence of morphologically abnormal embryos was reduced by subculturing every 20 days. Calli which were isolated and grown on a 2,4-D medium were more embryogenic than those on NAA. These embryos multiplied continuously for more than 10 months by a repetitive somatic embryogenic process. A third stage medium, supplemented with BAP (2 mg/l), was required for axis elongation, germination and transfer to soil. 相似文献
11.
A protocol has been developed for achieving somatic embryogenesis and plant regeneration from petiole-derived callus of Heracleum candicans Wall. Callus was initiated on MS medium supplemented with 0.5 mg l–1 2,4-D and 0.5 mg l–1 BAP and subcultured on a medium containing double strength MS macrosalts, 1 mg l–12,4-D and 0.25 mg l–1 Kn. Numerous globular embryos were formed on the surface of the callus upon transfer to auxin-rich MS medium that lacked
cytokinins. The globular embryos differentiated into mature embryos only when 2,4-D was removed from the medium. Mature embryo
formation was significantly influenced by the pH of the medium and the addition of AgNO3 and ABA. Eighty-five percent of the somatic embryos were converted into plantlets when transferred to a medium supplemented
with 0.01 mg l–1 BAP and 0.01 mg l–1 IBA. The regenerated plants have been established in soil and appear to be identical to the parent plants in morphology and
chromosome number.
Received: 5 November 1997 / Revision received: 9 February 1998 / Accepted: 19 February 1998 相似文献
12.
Somatic embryos were obtained from immature zygotic embryos of Cedrela fissilis Well. (Meliaceae), after a culture period of 12 months, with regular subcultures every 6–8 weeks. Callus was developed on explants in 2 months
on Murashige and Skoog (MS) medium containing 2,4 dichlorophenoxyacetic acid (2,4-D) or picloram (PIC). When the calli were
transferred to fresh medium, embryogenic tissue appeared on MS + 45 μM 2,4-D, or 22.5 μM 2,4-D + 0.4 μM 6-benzyladenine (BA),
or 20.7 μM PIC after 6 months. Sub-culture of embryogenic tissue in MS medium supplemented with 4.5 μM 2,4-D resulted in the
differentiation into somatic embryos after further 4 months. Repeated secondary somatic embryogenesis was achieved by regular
subculture on this medium. Maturation and conversion of somatic embryos into plantlets was achieved on MS medium without plant
growth regulators and the conversion frequency was approximately 12.5 %. The plantlets were successfully acclimatized in pots
with soil. Histological studies showed that somatic embryos had no detectable connection with the mother explants and that
somatic embryos in advanced stages were bipolar with shoot and root apical meristems, they contained vascular system and showed
typical characteristics of a somatic dicotyledonous embryo. 相似文献
13.
W. A. Parrott J. N. All M. J. Adang M. A. Bailey H. R. Boerma C. N. Stewart Jr. 《In vitro cellular & developmental biology. Plant》1994,30(3):144-149
Summary Lepidopteran insects are major defoliating pests of soybean in the southeastern United States. Soybean plants transgenic for
a nativecryIA(b) gene fromBacillus thuringiensis var.kurstaki HD-1 were obtained. Embryogenic cultures were induced by plating cotyledons on a Murashige and Skoog-based medium supplemented
with 40 mg/liter of 2,4-dichlorophenoxyacetic acid (2,4-D). The embryogenic cultures were maintained in liquid medium containing
5 mg/liter 2,4-D. These cultures were subjected to microprojectile bombardment, followed by selection on 50 mg/liter hygromycin.
Resistant embryogenic cell lines were transferred to growth regulator-free medium to permit recovery of mature somatic embryos.
After a desiccation period, the somatic embryos were returned to growth regulator-free medium for conversion into plants.
Southern hybridization analysis verified transformation. Feeding assays of T1 plants from one cell line deterred feeding, development, and survival of velvetbean caterpillar at a level comparable to
that of GatIR81-296, a soybean breeding line with a high level of insect resistance. Reduced feeding on T1 plants correlated with the presence of the transgene. 相似文献
14.
Xiang Ling You Xiao Tan Jin Ling Dai Yu Hua Li Yong Eui Choi 《Plant Cell, Tissue and Organ Culture》2012,108(2):333-338
An efficient system for inducing somatic embryogenesis in Panax notoginseng was established using shaker flasks and bioreactor cultures; furthermore, regenerated plantlets were successfully transferred
to ex vitro soil conditions. Embryogenic callus was induced from segments of adventitious roots incubated on Murashige and
Skoog (MS) medium containing 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) after 5 weeks of culturing. The highest frequency
(100%) of somatic embryogenesis, with a mean of 32.7 somatic embryos per callus, was obtained on embryogenic callus incubated
on a medium containing 0.5 mg/L 2,4-D. To scale-up somatic embryo formation, 10 g (~1.65 × 104) of early globular-stage somatic embryos were incubated in a 3 L airlift bioreactor containing 1.5 L 1/2 MS medium without
plant growth regulators (PGRs) for a period of 4 weeks; these globular-stage somatic embryos then developed into cotyledonary
embryos. When maintained on PGR-free medium, the cotyledonary embryos developed roots but did not develop shoots. However,
when they were treated with gibberellic acid (GA3), they continued to germinate and transformed into plantlets after 2 weeks of culture. Plantlets with well-developed shoots
and roots were transferred to an autoclaved vermiculite and perlite mixture, acclimatized for a period of 3 months and successfully
transferred to forest mountain soil. Following overwintering, these plants produced new growth. 相似文献
15.
E. Sofiari C.J.J.M. Raemakers E. Kanju K. Danso A.M. van Lammeren E. Jacobsen R.G.F. Visser 《Plant Cell, Tissue and Organ Culture》1997,50(1):45-56
NAA and 2,4-D were compared for their ability to induce somatic embryogenesis in cassava (Manihot esculenta Crantz). In all seven cultivars tested, only 2,4-D had the capacity to induce primary somatic embryos from leaf explants,
however, both NAA and 2,4-D were capable of inducing secondary somatic embryos. More secondary somatic embryos were formed
in NAA than in 2,4-D medium. Furthermore, the maturation period for secondary somatic embryos was shorter in NAA medium than
in 2,4-D medium. In some cultivars, repeated subculture of secondary somatic embryos in NAA medium resulted in a gradual shift
from somatic embryogenesis to adventitious root formation. This shift could be stopped and reversed by subculture of the material
in 2,4-D medium. In NAA medium the most secondary somatic embryos were formed when they were subcultured every 15 days whereas
in 2,4-D a 20 day subculture interval was optimal. Subculture of secondary somatic embryos at a high inoculum density (>1.5
g jar−1) in NAA medium did not result in the formation of secondary somatic embryos, whereas in 2,4-D it lead to the formation of
globular secondary somatic embryos. With 2,4-D the newly induced secondary somatic embryos were connected vertically to the
explant and with NAA medium horizontally. For all cultivars tested, desiccation stimulated normal germination of NAA-induced
somatic embryos. However, the desiccated, secondary somatic embryos required a medium supplemented with BA for high frequency
germination. The concentration of BA needed for high frequency germination was higher when the desiccated secondary somatic
embryos were cultured in light instead of dark. In only one cultivar desiccation enhanced germination of 2,4-D induced secondary
somatic embryos and in three other cultivars it stimulated only root formation.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
Summary A protocol was developed for high frequency somatic embryogenesis and plant regeneration from cotyledon and hypocotyl explants
of Eruca sativa. Explants grown on Murashige and Skoog (MS) medium supplemented with 4.52 μM 2,4-D formed embryogenic callus after 4 wk of culture. Secondary somatic embryos were also produced from primary somatic
embryos on MS medium containing 0.56 μM 2,4-D. Somatic embryos developed into mature embryos on MS medium in the presence of 45 gl−1 polyethylene glycol. After desiccation, somatic embryos developed into plantlets by culturing the mature somatic embryos
on 1/2 x MS medium containing 0.24 μM indole-3-butyric acid. 相似文献
17.
Immature seeds, as well as hypocotyls and cotyledons excised from seedlings of Myrtus communis L., were cultured on media containing half-strength Murashige and Skoog macronutrients (MS/2) with combinations of auxins
and cytokinins, in order to study their morphogenetic competence. Somatic embryogenesis was obtained from cotyledons, hypocotyls
and 2-month-old immature seeds with 0.1 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D). The percentage of explants showing this
primary somatic embryogenesis ranged from 4% for hypocotyls to 12% for 2-month-old immature seeds. In the latter, somatic
embryogenesis was also obtained in media containing 2,4-D plus a cytokinin, and with only a cytokinin. Somatic embryos obtained
from hypocotyls, cotyledons or immature seeds were able to develop on MS/2 medium without plant growth regulators. Subculture
of primary somatic embryos obtained from immature seeds on MS/2 medium without plant growth regulators gave rise to clusters
with secondary somatic embryos and embryogenic calli. These clusters were subcultured every 8 weeks, and they were the source
of highly embryogenic cultures. An average of 10% of the secondary somatic embryos developed into plantlets in each subculture.
Therefore, the same culture on MS/2 medium without growth regulators yielded both plantlets and de novo secondary embryos.
Received: 6 April 1998 / Revision received: 10 July 1998 / Accepted: 21 July 1998 相似文献
18.
Waxflowers (Chamelaucium spp.) are native to Australia and now are grown for the cut flower industry worldwide. As part of an effort to achieve somatic
hybridization between the species to improve flower quality, somatic embryogenesis was achieved for Chamelaucium uncinatum and C. repens. Somatic embryos from young leaves of C. uncinatum and C. repens were induced in vitro on Murashige and Skoog (MS) agar medium containing 20 g/l sucrose and 2,4-dichlorophenoxyacetic acid
(2,4-D). For C. uncinatum, up to 4% of explants developed somatic embryos at 20 μM 2,4-D and for C. repens, up to 3% developed somatic embryos at 5 μM 2,4-D. Somatic embryos of C. uncinatum were also induced from immature seeds—a maximum of 6% of seed explants producing somatic embryos on MS medium containing
0.05 μM 6-benzyladenine (BA) and 0.5 μM Naphthalene acetic acid (NAA). Somatic embryo cultures maintained on MS medium supplemented
with 0.1 μM 2,4-D were induced to develop into plantlets after transfer to a hormone-free medium under light. 相似文献
19.
Hypocotyl segments ofEleutherococcus senticosuscultured on Murashigeand Skoog's (MS) medium with 4.5 µM2,4-D produced somaticembryos directly from the surface of explants without interveningcallus formation. When these somatic embryos were subculturedto the same MS medium with 4.5 µM2,4-D, friable embryogeniccalli were formed mainly from radicle tips of somatic embryos,but at a low frequency (5%). Selected embryogenic calli weremaintained on MS agar or liquid medium with 4.5 µM2,4-D.To induce somatic embryo development, embryogenic calli andcell clumps were transferred to MS medium lacking 2,4-D. Thefrequency of somatic embryo formation differed between culturetypes with 1570 embryos formed per Petri dish from callus cultureand 5514 embryos formed per flask from cell suspension cultures.Somatic embryos formed on agar medium had larger cotyledonsthan those of embryos formed in liquid medium. GA3treatmentwas necessary to induce germination from somatic embryos. Therate of plant conversion was 97% in somatic embryos from callusculture and 76% in embryos from liquid culture. Regeneratedplantlets were successfully acclimatized in the glasshouse.Copyright1999 Annals of Botany Company Eleutherococcus senticosus, micro propagation, somatic embryogenesis. 相似文献
20.
Summary Indirect somatic embryogenesis, encapsulation, and plant regeneration was achieved with the rare rhoeophytic woody medicinal
plant Rotula aquatica Lour. (Boraginaceae). Friable callus developed from leaf and internode explants on Murashige and Skoog (MS) medium with 0.45 μM 2,4-dichlorophenoxyacetic, acid (2,4-D) was most effective for the induction of somatic embryos. Subculture of the callus
onto half-strength MS medium with the same concentration of 2,4-D resulted in highly embryogenic callus. Suspension culture
was superior to solid medium culture for somatic embryogenesis. Embryogenic callus.during subsequent transfer to suspension
cultures of half-strength MS medium having 0.23 μM 2,4-D induced the highest number of somatic embryos (a mean of 25.6 embryos per 100 mg callus) and the embryos were grown
up to the torpedo stage. Transfer of embryos to half-strength MS basal solid medium allowed development, of 50% of the embryos
to the cotyledonary stage. Of the cotyledonary embryos, 90% underwent conversion to plantlets on the same medium. Encapsulated
cotyledonary embryos exhibited 100% conversion to plantlets. Ninety-five percent of the plantlets established in field conditions
survived, and were morphologically identical to the mother plant. 相似文献