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1.
P. Jha C. B. Yadav V. Anjaiah V. Bhat 《In vitro cellular & developmental biology. Plant》2009,45(2):145-154
An efficient in vitro plant regeneration protocol through somatic embryogenesis and direct shoot organogenesis has been developed for pearl millet
(Pennisetum glaucum). Efficient plant regeneration is a prerequisite for a complete genetic transformation protocol. Shoot tips, immature inflorescences,
and seeds of two genotypes (843B and 7042-DMR) of pearl millet formed callus when cultured on Murashige and Skoog (MS) medium
supplemented with varying levels of 2,4-dichlorophenoxyacetic acid (2,4-D; 4.5, 9, 13.5, and 18 μM). The level of 2,4-D, the
type of explant, and the genotype significantly effected callus induction. Calli from each of the three explant types developed
somatic embryos on MS medium containing 2.22 μM 6-benzyladenine (BA) and either 1.13, 2.25, or 4.5 μM of 2,4-D. Somatic embryos
developed from all three explants and generated shoots on MS medium containing high levels of BA (4.4, 8.8, or 13.2 μM) combined
with 0.56 μM 2,4-D. The calli from the immature inflorescences exhibited the highest percentage of somatic embryogenesis and
shoot regeneration. Moreover, these calli yielded the maximum number of differentiated shoots per callus. An efficient and
direct shoot organogenesis protocol, without a visible, intervening callus stage, was successfully developed from shoot tip
explants of both genotypes of pearl millet. Multiple shoots were induced on MS medium containing either BA or kinetin (4.4,
8.8, 17.6, or 26.4 μM). The number of shoots formed per shoot tip was significantly influenced by the level of cytokinin (BA/kinetin)
and genotype. Maximum rooting was induced in 1/2 strength MS with 0.8% activated charcoal. The regenerated plants were transferred
to soil in pots, where they exhibited normal growth. 相似文献
2.
Seabuckthorn (Hippophae rhamnoides) is a multipurpose small tree with unique berries of high nutritional and pharmaceutical values. A clonally propagated plant
originating from a 20-year-old tree of H. r. rhamnoides × mongolica hybrid cultivar Julia and seedling offspring of this cultivar were investigated regarding induction of shoot organogenesis
in leaf explants and in roots of intact seedlings, and induction of direct somatic embryogenesis in explants from shoot tissue.
The highest percentage of leaf explants showing shoot organogenesis was achieved (juvenile explants, 65%; adult explants,
75%) when incubated in Murashige and Skoog (MS) medium supplemented with either 4.5 μM of the phenylurea cytokinin thidiazuron
(TDZ) or 2.25 μM TDZ plus 2.2 μM 6-benzyladenine (BA), for juvenile and adult explants, respectively, both supplemented with
0.53 μM α-naphthaleneacetic acid (NAA). Juvenile explants developed on average 18 shoots per explant in the MS medium supplemented
with 4.5 μM TDZ, a four fold increase over those incubated on the medium supplemented with 2.25 μM TDZ and 2.2 μM BA. Adult
leaf explants grown on medium containing 2.25 μM TDZ and 2.2 μM BA medium produced 12 shoots per explant, while those grown
on medium containing 4.5 μM TDZ produced 5 shoots per explant. Shoot organogenesis was observed in roots of intact seedlings
pre-cultured on plain medium lacking nutrients (PM) or woody plant medium (WPM) salts and then grown on WPM salts supplemented
with 4.4 μM BA, 0.29 μM gibberrelic acid (GA3), and 57.0 μM indoleacetic acid (IAA). The number of shoots formed on each seedling
root system was ten fold higher when the pre-culture was in WPM medium indicating a promoting effect of mineral nutrients
in the pre-culture medium. Somatic embryogenesis was induced in both juvenile and adult leaf explants in 65 and 78% of the
explants, respectively, in MS-based medium supplemented with 2.0 μM N-(2-Chloro-4-pyridyl)-N
1-phenylurea (CPPU), 0.53 μM NAA and varying concentrations of BA. There was an interaction effect between MS salt strength
and BA concentration. The most effective medium for inducing somatic embryogenesis in juvenile explants contained half strength
MS salts and 2.2 μM BA and full strength MS salts and 13.2 μM BA for adult explants. 相似文献
3.
Guohua Ma Jinfeng Lü Jaime A. Teixeira da Silva Xinhua Zhang Jietang Zhao 《Plant Cell, Tissue and Organ Culture》2011,104(2):157-162
Ochna integerrima is a medicinal and ornamental plant in Southeastern Asia. It has been listed as a rare and endangered species in China. Here
we studied the effects of plant growth regulators and their concentrations on the induction of somatic embryogenesis and shoot
organogenesis from leaf and shoot explants of O. integerrima for the first time. Cytokinins played a crucial role in somatic embryogenesis and shoot organogenesis. Among them, a higher
concentration of thidiazuron (10.0–15.0 μM TDZ) could induce both somatic embryogenesis and adventitious shoot formation whereas
low concentrations of TDZ (5.0 μM) could only induce adventitious shoots. However, 6-benzyladenine (BA at 5–15 μM) could only
induce adventitious shoots. Shoot explants induced more adventitious shoots and somatic embryos than leaf explants when cultured
on medium with the same concentration (5–15 μM) of TDZ or 15 μM BA. Medium containing 0.5 μM α-naphthaleneacetic acid and
8 μM indole-3-butyric acid and 0.1% activated charcoal could induce adventitious roots within 1 month. An efficient mass propagation
and regeneration system has been established. 相似文献
4.
The induction of somatic embryogenesis from shoot apices and leaf explants of shoot cultures derived from 6- to 7-year-old
white oak (Quercus alba L.) trees is reported in this study. Embryogenic response was obtained in two out of the three genotypes evaluated with embryo
induction frequencies up to 50.7% for WOQ-1 and 3.4% for WOQ-5 genotypes. The embryogenic explants formed translucent nodular
structures and cotyledonary-stage somatic embryos, which developed from callus tissue, indicating an indirect embryogenesis
process. An efficient procedure was developed for WOQ-1 material on the basis of the most appropriate leaf developmental stage.
Growing leaves excised from two nodes below the shoot apex showed the highest embryogenic induction index. These leaves contain
cells in an undifferentiated state, as shown by the presence of precursor cells of stomata, absence of intercellular spaces
and low starch content in the mesophyll cells. Nodular structures and/or somatic embryos began to arise 7–8 weeks after culture
initiation, although most emerged after 9–12 weeks in culture. The sequence of application of media for somatic embryo induction
was optimized with a two-step procedure consisting of culturing the explants in medium supplemented with 21.48 μM NAA and
2.22 μM BA for 8 weeks and transfer of explants into plant growth regulator-free medium for another 12 weeks. Clonal embryogenic
lines were established and maintained by secondary embryogenesis. Embryo germination (30%) and plantlet conversion (16.6%)
were achieved after cold storage for 2 months. 相似文献
5.
T. H. Lan P. I. Hong C. C. Huang W. C. Chang C. S. Lin 《In vitro cellular & developmental biology. Plant》2009,45(1):44-47
Whole plants were regenerated from excised leaves of Drimiopsis kirkii Baker (Lily of the Valley) through direct somatic embryogenesis. An initial exposure to a low level of 2,4-dichlorophenoxyacetic
acid (2,4-D, 0.45 μM) in the medium was essential in inducing the direct formation of somatic embryos. A high concentration
of 2,4-D (4.52 μM) in the proliferation medium reduced embryogenesis and enhanced callus formation. The presence of kinetin
in the medium enhanced the somatic-embryogenesis-inducing effect of 2,4-D (0.45 μM). The maximum embryogenesis rate (4,026
somatic embryos per gram of leaf) was obtained in explants cultured for 30 d in medium supplemented with 2.33 μM kinetin and
0.45 μM 2,4-D (embryo induction medium). Kinetin (4.65 μM) also enhanced embryo germination (97.6%), but the presence of α-naphthalene
acetic acid in the medium drastically reduced embryo germination. Following conversion, the regenerated plantlets were transferred
to soil and showed normal morphological characteristics. 相似文献
6.
A simple and efficient system was developed for rapid somatic embryogenesis from leaf explants of Merwilla plumbea, a traditional but threatened medicinal plant in South Africa. Friable embryogenic callus (FEC) was obtained from leaf explants
on embryogenic callus induction medium containing agar-solidified Murashige and Skoog (MS) salts and vitamins, 8.3 μM picloram,
2.3 μM thidiazuron (TDZ) and 20 μM glutamine. FEC was subsequently incubated in embryogenic callus proliferation medium containing
4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.1 μM picloram for 7 days before it was transferred to liquid somatic embryo
medium (SEML) containing MS medium supplemented with 0.4 μM picloram and 0.9 μM TDZ. In SEML supplemented with 150 mg L−1 haemoglobin, 5.4–35.6 somatic embryos per settled cell volume of 500 mg FEC were obtained. These embryos were at globular
to cotyledonary developmental stages. Embryo maturation, germination and plant formation rate was 94.4% following transfer
of SEs to half-strength MS medium supplemented with 1.4 μM gibberellic acid. Plantlets transferred into soil acclimatized
in the misthouse and established successfully in the greenhouse (100%). This is the first report on induction of Merwilla plumbea somatic embryogenesis. The protocol developed offers controlled vegetative propagation by alleviating extinction threats,
ensures germplasm conservation and provides a system for physiological, biochemical, molecular and cellular studies of embryo
development. 相似文献
7.
Murugesan Dhandapani Doo Hwan Kim Seung-Beom Hong 《In vitro cellular & developmental biology. Plant》2008,44(1):18-25
High-frequency plant regeneration of C. roseus cv. ‘little bright eye’ via somatic embryogenesis and organogenesis from five out of six explants was standardized. Two factors
were found to be important for regeneration: (1) the type of explants, and (2) the combination and concentrations of plant
growth regulators. The highest regeneration percentage through somatic embryogenesis was obtained from mature zygotic embryo
in MS medium supplemented with 7.5 μM of thidiazuron (TDZ). The mature embryo also regenerated efficiently via organogenesis
in MS medium supplemented with either 2.5 μM TDZ or 5.3 μM α-naphthalene acetic acid (NAA) and 2.2 μM 6-benzylaminopurine
(BA). Hypocotyl and cotyledon did not induce somatic embryogenesis and organogenesis in TDZ-containing medium but gave a maximum
percentage of shoots in MS medium supplemented with 5.3 μM NAA and 2.2 μM BA. Stem nodes and meristem tips showed better regeneration
via organogenesis in the medium supplemented with NAA and BA and in lower concentrations of TDZ. 相似文献
8.
Burma reed (Neyraudia arundinacea Henr.) is a C4 grass native to Southeast Asia and Indomalaya that grows quickly, exhibits strong resistance to environmental stresses, and
is extremely adaptable. It can be widely utilized as a bioenergy crop for biomass conversion. In vitro multiple shoots were
first established from axillary buds and then subcultured on propagation medium containing 10 μM 6-benzylaminopurine (BA)
and 2.0 μM naphthaleneacetic acid (NAA). Multishoot clumps were used as explants to induce somatic embryogenesis and adventitious
shoot formation. The results showed that auxin 2,4-dichlorophenoxyacetic acid or NAA play a key role for the induction of
somatic embryogenesis and adventitious shoot formation, whereas cytokinin BA or kineatin enhance shoot proliferation and plant
regeneration from callus and somatic embryos. Efficient somatic embryogenesis, mass propagation, and plant regeneration systems
in Burma reed were established. 相似文献
9.
Shyamkumar Barampuram Byung Yeoup Chung Seung Sik Lee Byung Chull An Eun Mi Lee Jae-Young Cho 《In vitro cellular & developmental biology. Plant》2009,45(2):155-161
The present study demonstrates the establishment of embryogenic tissue from seeds and (seedling-derived hypocotyls) shoot
base explants derived from seedlings of Eremochloa ophiuroides. The highest percentage of callus induction obtained from seed and young shoot base explants was 52.0% and 66.6% on Murashige
and Skoog (MS) basal media supplemented with 9.0 μM and 18.1 μM 2,4-dichlorophenoxyacetic acid (2,4-D), respectively. The
type of callus obtained from both types of explants was off-white to yellow in color and non-friable and shiny in texture.
Excised callus from the explants was subcultured onto fresh media of the same recipe for further proliferation. After 10–12 d
of subculture, a yellow, globular, friable embryogenic callus was obtained from the initial callus. The highest percentage
of embryogenic calli obtained at 40.0% was observed on media containing 2.2 μM 2,4-D. The highest regeneration rate of 46.6%
was observed on MS media supplemented with 0.4 μM 2,4-D and 2.2 μM benzylaminopurine (BA). Regenerated shoots were rooted
in MS basal medium. Plants with well-developed roots were transferred to pots containing a soil mix and acclimatized in greenhouse
conditions. Four weeks post-transfer, acclimatized plants showed 100% survival and remained healthy and green. This is the
first report of a successful method for induction of somatic embryogenesis with subsequent plant regeneration in centipede
grass and demonstrates the establishment of embryogenic callus and efficient plant regeneration with potential application
in the development of genetic transformation systems for centipede grass. 相似文献
10.
A new Agrobacterium-mediated transformation system was developed for finger millet using shoot apex explants. The Agrobacterium strain LBA4404 harboring binary vector pCAMBIA1301, which contained hygromycin phosphotransferase (hptII) as selectable marker gene and β-glucuronidase (GUS) as reporter gene, was used for optimization of transformation conditions.
Two finger millet genotypes, GPU 45 and CO 14, were used in this study. The optimal conditions for the Agrobacterium-mediated transformation of finger millet were found to be the co-cultivation of explants obtained on the 16th day after callus
induction (DACI), exposure of explants for 30 min to agrobacterial inoculum and 3 days of co-cultivation on filter paper placed
on medium supplemented with 100 μM acetosyringone (AS). Addition of 100 μM l-cysteine in the selection medium enhanced the frequency of transformation and transgenic plant recovery. Both finger millet
genotypes were transformed by Agrobacterium. A frequency of 19% transient expression with 3.8% stable transformation was achieved in genotype GPU 45 using optimal conditions.
Five stably transformed plants were fully characterized by Southern blot analysis. A segregation analysis was also performed
in four R1 progenies, which showed normal Mendelian pattern of transgene segregation. The inheritance of transgenes in R1 progenies was also confirmed by Southern blot analysis. This is the first report on Agrobacterium-mediated transformation of finger millet. This study underpins the introduction of numerous agronomically important genes
into the genome of finger millet in the future. 相似文献
11.
Xingyu Yang Jinfeng Lü Jaime A. Teixeira da Silva Guohua Ma 《Plant Cell, Tissue and Organ Culture》2012,109(2):213-221
Primulina tabacum is a rare and endangered species that is endemic to China. Establishing an efficient regeneration system is necessary for
its conservation and reintroduction. In this study, when leaf explants collected from plants grown in four ecotypes in China
are incubated on Murashige and Skoog (MS) medium containing 5.0 μM thidiazuron (TDZ) for 30 days, then transferred to medium
containing 5.0 μM 6-benzyladenine (BA), adventitious shoots are then observed. Conversely, when leaf explants are incubated
on medium containing 5.0 μM BA for 30 days, then transferred to medium containing 5.0 μM TDZ, somatic embryogenesis is induced.
This indicates that somatic embryogenesis and shoot organogenesis could be switched simply by changing the order of two cytokinins
supplemented in the culture medium. Histological investigation has revealed that embryogenic cells are induced within 30 days
following incubation of explants in medium containing TDZ. Only if embryogenic cells were induced, TDZ could enhance somatic
embryogenesis and BA could stimulate shoot organogenesis. When comparing explants from different ecotypes, leaf explants
from Zixiadong in Hunan Province could induce low numbers (1–2) of either somatic embryos or adventitious shoots on medium
containing either 5.0 μM TDZ or 5.0 μM BA, respectively. Whereas, leaf explants from plants collected from the other three
ecological habitats could induce 50–70 somatic embryos/adventitious shoots per explant. Moreover, somatic embryos could induce
secondary somatic embryogenesis and adventitious shoots on different media. All regenerated shoots developed adventitious
roots when these are transferred to rooting medium, and over 95% of plantlets have survived following acclimatization and
transfer to a potting mixture (1:1, sand:vermiculite). 相似文献
12.
Perera PI Hocher V Verdeil JL Doulbeau S Yakandawala DM Weerakoon LK 《Plant cell reports》2007,26(1):21-28
Unfertilized ovaries isolated from immature female flowers of coconut (Cocos nucifera L.) were tested as a source of explants for callogenesis and somatic embryogenesis. The correct developmental stage of ovary explants and suitable in vitro culture conditions for consistent callus production were identified. The concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) and activated charcoal was found to be critical for callogenesis. When cultured in a medium containing 100 μM 2,4-D and 0.1% activated charcoal, ovary explants gave rise to 41% callusing. Embryogenic calli were sub-cultured into somatic embryogenesis induction medium containing 5 μM abscisic acid, followed by plant regeneration medium (with 5 μM 6-benzylaminopurine). Many of the somatic embryos formed were complete with shoot and root poles and upon germination they gave rise to normal shoots. However, some abnormal developments were also observed. Flow cytometric analysis revealed that all the calli tested were diploid. Through histological studies, it was possible to study the sequence of the events that take place during somatic embryogenesis including orientation, polarization and elongation of the embryos. 相似文献
13.
A simple, high frequency, and reproducible method for plant regeneration through direct organogenesis from cotyledonary leaf
explants of Jatropha curcas was developed using Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ) or 6-benzyl
aminopurine (BAP). Medium containing TDZ has greater influence on regeneration as compared to BAP. The induced shoot buds
were transferred to MS medium containing 10 μM kinetin (Kn), 4.5 μM BAP, and 5.5 μM α-naphthaleneacetic acid (NAA) for shoot
proliferation. The proliferated shoots could be elongated on MS medium supplemented with different concentrations and combinations
of BAP, indole-3-acetic acid (IAA), NAA, and indole-3-butyric acid (IBA). MS medium with 2.25 μM BAP and 8.5 μM IAA was found
to be the best combination for shoot elongation. However, significant differences in plant regeneration and shoot elongation
were observed among the genotypes studied. Rooting was achieved when the basal cut end of elongated shoots were dipped in
half strength MS liquid medium containing different concentrations and combinations of IBA, IAA, and NAA for 4 days, followed
by transfer to growth regulators free half strength MS medium supplemented 0.25 mg l−1 activated charcoal. Elongated shoot treated with 15 μM IBA, 5.7 μM IAA, and 11 μM NAA resulted in highest percent rooting.
The rooted plants could be established in soil with more than 90% survival rate. The method developed may be useful in improvement
of J. curcas through genetic modification. 相似文献
14.
A protocol has been developed for the induction of somatic embryogenesis from flower explants of chamomile (Chamomilla recutita L.). The effects of several plant growth regulators [α-naphthylacetic acid (NAA), 2,4-dichlorophenoxyacetic acid, 6-benzyladenine (BA) and kinetin (Kin), alone or in combination]
and the flower type (disk or ray flower) were investigated. Both types of flowers responded to the callus and shoot induction
treatments, but formation of globular somatic embryos took place only on disk-flower-derived explants after 2–4 weeks of culture
on a Murashige and Skoog (MS) medium supplemented either with 8.87 μm BA and 1.07 μm NAA or with 26.8 μm NAA and 11.5 μm Kin. However, fully developed, cotyledonary-stage somatic embryos could be induced only on the NAA/Kin medium, 10 weeks after
culture initiation. Germination of the embryos and plant regeneration took place after subculture for 4–5 weeks onto medium
of the same composition. Plantlets regenerated from embryos flowered in vitro on a MS medium supplemented with 8.87 μm BA and 1.07 μm NAA. The significance of the results with respect to chamomile micropropagation and the utilization of wild populations in
breeding programs is discussed.
Received: 6 April 1998 / Revision received: 12 October 1998 / Accepted: 28 October 1998 相似文献
15.
G. H. Ma C. X. He H. Ren Q. M. Zhang S. J. Li X. H. Zhang B. Eric 《Biologia Plantarum》2010,54(2):361-365
An efficient propagation system via somatic embryogenesis and shoot organogenesis and plant regeneration system for endangered species Primulina tabacum Hance was established. Thidiazuron (TDZ) was the key plant growth regulator for inducing somatic embryogenesis and kinetin
(KIN) and 6-benzylaminopurine (BAP) were the key cytokinins for inducing shoot organogenesis from leaf explants. TDZ combined
with BAP or KIN in the induction Murashige and Skoog medium induced both somatic embryos and adventitious shoots. Leaf explants
with abaxial site in contact with the medium induced less somatic embryos or adventitious shoots compared to inversely placed
leaf explants and the optimum pH was 6.5–7.0. Secondary somatic embryos or adventitious shoot could be induced from primary
somatic embryos using TDZ and BAP. Shoots developed adventitious roots on rooting medium containing 0.5 μM indole-3-butyric
acid and 0.2 % activated carbon. Over 90 % of plantlets survived following acclimatization and transfer to potting mixture
(sand:Vermiculite:limestone; 1:2:1). 相似文献
16.
Filipendula ulmaria (L.) Maxim (meadowsweet) is a medicinal plant that is claimed to have several biological activities, including anti-tumor,
anti-carcinogenic, anti-oxidant, anti-coagulant, anti-ulcerogenic, anti-microbial, anti-arthritic, and immunomodulatory properties.
This report describes, for the first time, an efficient plant regeneration system for F. ulmaria via adventitious shoot development from leaf, petiole, and root explants cultured on Murashige and Skoog’s minimal organics
medium containing different concentrations of thidiazuron (TDZ), benzyladenine, and kinetin either alone or in combination
with different auxins. Relatively extensive/prolific shoot regeneration was observed in all three explant types with TDZ in
combination with indole-3-acetic acid (IAA). Gibberellic acid (GA3), TDZ, and IAA combinations were also tested. The best shoot proliferation was observed among root explants cultured on media
supplemented with 0.45 μM TDZ + 2.85 μM IAA + 1.44 μM GA3. Regenerated shoots were transferred to rooting media containing different concentrations of either IAA, indole-3-butyric
acid (IBA), naphthalene acetic acid, or 2,4-dichlorophenoxyacetic acid. Most shoots developed roots on medium with 2.46 μM
IBA. Rooted explants were transferred to vermiculite in Magenta containers for a 2-wk acclimatization period and then finally
to plastic pots containing potting soil. The plantlets in soil were kept in growth chambers for 2 wk before transferring to
greenhouse conditions. 相似文献
17.
Vinod Kumar Ashwani Sharma Bellur Chayapathy Narasimha Prasad Harishchandra Bhaskar Gururaj Parvatam Giridhar Gokare Aswathanarayana Ravishankar 《Acta Physiologiae Plantarum》2007,29(1):11-18
Direct shoot bud induction and plant regeneration was achieved in Capsicum frutescens var. KTOC. Aseptically grown seedling explants devoid of roots, apical meristem and cotyledons were inoculated in an inverted
position in medium comprising of Murashige and Skoog (Physiol Plant 15:472–497, 1962) basal medium supplemented with 2-(N-morpholine) ethanesulphonic acid buffer along with 2.28 μM indole-3-acetic acid, 10 μM silver nitrate and either of 13.31–89.77 μM
benzyl adenine (BA), 9.29–23.23 μM kinetin, 0.91–9.12 μM zeatin, 2.46–9.84 μM 2-isopentenyl adenine. Profuse shoot bud induction
was observed only in explants grown on a media supplemented with BA (26.63 μM) as a cytokinin source and 19.4 ± 4.2 shoot
buds per explant was obtained in inverted mode under continuous light. Incorporation of polyamine inhibitors in the culture
medium completely inhibited shoothoot bud induction. Incorporation of exogenous polyamines improved the induction of shoot
buds under 24 h photoperiod. These buds were elongated in MS medium containing 2.8 μM gibberellic acid. Transfer of these
shoots to hormone-free MS medium resulted in rooting and rooted plants were transferred to fields. This protocol can be efficiently
used for mass propagation and presumably also for regeneration of genetically transformed C. frutescens. 相似文献
18.
Epicotyl, petiole, and cotyledon explants derived from 14-d-old seedlings of Albizia odoratissima were cultured on Murashige and Skoog (MS) basal medium supplemented with different concentrations of either 6-benzylaminopurine
(BAP) solely or in combination with 0.5 μM naphthalene-3-acetic acid (NAA). The percentage of shoot regeneration and the number
of shoots regenerated varied significantly depending on the type of explants used, the concentration of plant growth regulators,
and the orientation of explants on the culture medium. The best response in terms of the percentage of shoot regeneration
was obtained from epicotyls cultured horizontally on MS medium supplemented with 5 μM BAP, whereas the highest number of shoots
per responding explant was recorded on medium containing 2.5 μM BAP and 0.5 μM NAA. Successful rooting was achieved by placing
the microshoots onto MS medium containing 25 μM indole-3-butyric acid (IBA) for 24 h first, then transferring to the same
medium without IBA. Of the various substrates tested, vermiculite was the best for plant acclimatization, as 75% of the plants
survived and became established. 相似文献
19.
Justicia gendarussa is a valuable medicinal plant and various parts of this plant are pharmaceutically used for the treatment of different diseases.
In vitro regeneration of shoot buds was obtained from culture of nodal cuttings as well as shoot regeneration from callus.
The nodal cuttings differed in shoot proliferation in terms of percentage of explants that responded and average shoot length
with various concentrations (4.4, 8.9, 13.3, 17.7, 22.2 μM) of 6-benzyladenine (BA), kinetin (Kn) and thidiazuron. In all
treatments, one shoot was invariably present. Optimum 87% of cultures responded with an average shoot length of 4.4 cm on
Murashige and Skoog (MS) medium supplemented with 17.7 μM BA. Callus was induced from the mature leaf segments on MS medium
supplemented with Kn (4.7, 13.9, 23.2 μM) alone or in combination with 2, 4-dichlorophenoxyacetic acid (2, 4-D; 2.3 μM, 4.5 μM).
Optimum callus induction (78%) was obtained on MS medium supplemented with 14 μM Kn and 4.5 μM 2, 4-D. When the callus was
subcultured on MS medium fortified with BA (8.9, 17.7, 26.6 μM) or Kn (9.3, 18.6, 27.9 μM) alone or in combination with α
naphthalene acetic acid (NAA; 2.7, 5.4 μM), shoot regeneration was obtained. The highest response (92%) was observed on MS
medium containing 17.7 μM BA and 5.4 μM NAA. On this medium, an average number of 12.2 shoots were obtained per responding
callus. The shoots obtained from callus and nodal cuttings were rooted with a frequency of 73% on MS medium augmented with
9.8 μM indole-3-butyric acid. The rooted shoots were successfully transplanted to soil and sand mixture (1:1) with 90% survival
rate. The protocol standardized for shoot proliferation and regeneration in J. gendarussa from nodal cuttings and leaf-derived callus is suitable for micropropagation and conservation of this essential medicinal
plant. 相似文献
20.
Ezz Al-Dein Al-Ramamneh Sridevy Sriskandarajah Margrethe Serek 《Plant Cell, Tissue and Organ Culture》2006,84(3):333-342
Somatic embryogenesis was induced from phylloclade explants of Schlumbergera truncata cv. Russian Dancer. Callus developed on phylloclade explants and sub-cultured over a period of 16 months on MS medium containing
mainly cytokinins was superior for the induction of somatic embryos compared to callus grown for a shorter time in the establishment
medium. Sub-culture of callus grown in SH-or MS-based liquid media supplemented with 7.0 μM kinetin and transferred onto solid
MS-based medium with either 0.45 μM 2,4-D or without hormones resulted in the differentiation into somatic embryos. SH-based medium proved better than MS-based medium
when used as the first medium for the induction of somatic embryogenesis. However, somatic embryogenesis, contrary to adventitious
shoot formation, was reduced when 2,4-D was included in the MS-based medium used for final transfer compared to the medium without growth regulators, indicating
that a critical hormonal balance was reached. Somatic embryos developed root and shoot poles when grown on G medium. On this
medium approximately 70% germination was recorded in the embryos that were differentiated earlier from the callus that was
grown for a longer time in the establishment medium. This callus was grown on either SH- or MS-based medium supplemented with
7.0 μM kinetin, and then transferred after 30 days (from SH medium) onto MS medium without hormones or after 40 days (from
MS medium) onto MS medium with 0.45 μM 2,4-D. Furthermore, plants from somatic embryos were successfully potted in soil and showed further growth and formation of a second
set of phylloclades (secondary phylloclades). Histological studies showed that somatic embryos had no detectable connection
with the mother explants and that advanced stages of somatic embryos had a contained vascular system. In addition to the normal
dicotyledonous embryos, anomalous embryos with multiple cotyledons and vase-like embryos were observed. Secondary embryos
were also recorded in this study. 相似文献