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1.
Maurecilne Lemes da Silva Daniela Lopes Paim Pinto Miguel Pedro Guerra Eny Iochevet Segal Floh Cláudio Horst Bruckner Wagner Campos Otoni 《Plant Cell, Tissue and Organ Culture》2009,99(1):47-54
The objective of the present work was to induce somatic embryogenesis from zygotic embryos of Passiflora cincinnata Masters. Zygotic embryos formed calli on media with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and
4.5 μM benzyladenine (BA) after 30 days of in vitro culture. A concentration of 18.1 μM 2,4-D resulted in the largest number
of somatic embryos. Embryogenic calli were yellowish and friable, forming whitish proembryogenic masses. Morphologically,
embryogenic cells were small and had large nuclei and dense cytoplasm, whereas non-embryogenic cells were elongated, with
small nuclei and less dense cytoplasm. Calli cultured under white light on basal Murashige and Skoog’s medium with activated
charcoal produced embryos in all developmental stages. There were differences among the treatments, with some leading to the
production of calli with embryos and some only to callus formation. Some abnormalities were associated with somatic embryos,
including fused axes, fused cotyledons and polycotyledonary embryos. Production of secondary somatic embryos occurred in the
first cycle of primary embryo development. Secondary embryos differentiated from the surface of the protodermal layer of primary
embryos with intense cell proliferation, successive mitotic divisions in the initial phase of embryoid development, and a
vascular system formed with no connection to the parental tissue. This secondary embryogenic system of P. cincinnata is characterized by intense proliferation and maintenance of embryogenic competence after successive subcultures. This reproducible
protocol opens new prospects for massive propagation and is an alternative to the current organogenesis-based transformation
protocol. 相似文献
2.
Małgorzata Malik 《Plant Cell, Tissue and Organ Culture》2008,94(3):337-345
Alternative procedures for the production of Narcissus L. somatic embryos were investigated. Somatic embryogenesis was initiated on ovary explants isolated from cv. Carlton bulbs,
chilled for 12 weeks at 5°C. The explants were cultured on MS media with 3% sucrose and growth regulators: Picloram or 2,4-D
(10 or 25 μM) and BA (1 or 5 μM) for 12 weeks in the culture systems: continuous cultivation on solid media, continuous cultivation
in liquid media and sequential cultivation using cycles in liquid and solid media. Two types of somatic embryogenesis, indirect
and direct, were observed. The developmental pathway depended on the period of exposure to liquid media. Somatic embryos were
formed via embryogenic nodular callus on solid media. 2,4-D and BA stimulated the process. The 4-week and 8-week liquid medium
treatments resulted in the development of somatic embryos directly from the ovary explant tissue. The highest number of somatic
embryos was noted under the influence of 25 μM 2,4-D and 5 μM BA in explants cultivated for 8 weeks in liquid medium and then,
for 4 weeks, on solid medium. The effects of inoculum density on biomass increase and the formation of somatic embryos in
cultures obtained on a medium with 25 μM 2,4-D and 5 μM BA were also checked. The highest biomass increase was observed after
subculturing in liquid medium containing 0.5 μM NAA and 5 μM BA when the density of inoculum was 0.5 g/25 ml of the medium.
The highest number of somatic embryos was noted when the density of inoculum was 1.5 g/25 ml. 相似文献
3.
In the present study, the procedures for induction of somatic embryogenesis (SE) in an in vitro culture of the tulip have been developed. SE was initiated on flower stem explants isolated from “Apeldoorn” bulbs during
their low-temperature treatment. Bulbs had not been chilled or had been chilled for 12 or 24 weeks at 5°C. The explants were
cultured with exogenous auxins 2,4-dichlorophenoxyacetic acid (2,4-D), 4-amino-3,5,6-trichloropicolinic acid (Picloram), α-naphthaleneacetic
acid (NAA) at 1–100 μM and cytokinins: benzyladenine (BA) and zeatin (ZEA) at 0.5–50 μM. Increase in auxin concentrations
caused an intensive enlargement of the explant parenchyma, which changed into homogenous colorless callus. On the same media,
vein bundles developed into yellowish, nodular callus. Picloram was more efficient in inducing the formation of embryogenic
nodular callus than 2,4-D, whereas the latter stimulated formation of colorless callus. The base of the lower part of the
flower stem isolated from bulbs chilled for 12 weeks proved to be the best explant for callus formation. The highest number
of somatic embryos was produced on medium with 25 μM Picloram and 0.5 μM BA. Development of adventitious roots was noticed
in the presence of 2,4-D. Globular embryos developed into torpedo stage embryos under the influence of BA (5 μM) and NAA (0.5 μM).
Morphological and anatomical data describing development of callus and somatic embryos are presented. 相似文献
4.
Veena Agrawal Pratima Rani Sardar 《In vitro cellular & developmental biology. Plant》2007,43(6):585-592
In vitro regeneration through somatic embryogenesis as well as organogenesis using cotyledon of a woody medicinal legume, Cassia angustifolia is reported. The cotyledons dissected from semi-mature seeds, if inoculated on Murashige and Skoog’s medium (MS) supplemented
with auxin alone or in combination with cytokinin, produced direct and indirect somatic embryos. A maximum of 14.36 ± 2.26
somatic embryos per 20 mg of explants including callus were produced in 70% cultures on MS medium with 2.5 μM benzyladenine
(BA) + 10 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Although the percentage of embryogenic cultures was higher (83.33%) at
10 μM 2,4-D + 1 μM BA, the average number of somatic embryos was much less (7.6 ± 0.85) at this level, whereas at 2.5 μM BA
and 5 μM 2,4-D, there was a simultaneous formation of both somatic embryos and shoots. The somatic embryos, although started
germinating on the same medium, developed into full plantlets only if transferred to MS basal with 2% sucrose. Cytokinins
alone did not induce somatic embryogenesis, but formed multiple shoots. Five micromolar BA proved optimum for recurrently
inducing shoots in the competent callus with a maximum average of 12.04 ± 2.10 shoots and shoot length of 2.26 ± 0.03 cm.
Nearly 91.6% shoots (2–2.5 cm in size) organized an average of 5.12 ± 0.58 roots on half strength MS + 10 μM indole-3-butyric
acid. All the plantlets have been transferred successfully to soil. Types of auxin and its interaction with cytokinin significantly
influenced somatic embryogenesis. 相似文献
5.
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
6.
Daniela Lopes Paim Pinto Ana Maria Rocha de Almeida Mailson Monteiro Rêgo Maurecilne Lemes da Silva Evelyn Jardim de Oliveira Wagner Campos Otoni 《Plant Cell, Tissue and Organ Culture》2011,107(3):521-530
Mature zygotic embryos of three genotypes of Passiflora edulis Sims, including ‘FB-100’, ‘FB-200’, and ‘FB-300’ were incubated on a Murashige and Skoog (MS) (1962) medium supplemented with different concentrations (18.1–114.8 μM) of 2,4-diclorophenoxyacetic acid (2,4-D) and 4.4 μM of
6-benzyladenine (BA). MS basal medium and MS with BA induced germination of P. edulis embryos. The highest frequencies of embryogenic calli were observed when explants were incubated on MS medium supplemented
with 72.4 μM 2,4-D and 4.4 μM BA for ‘FB-200’, which showed the highest potential for embryogenic callus formation. Cytological
and histological analyses of pro-embryogenic callus revealed two distinct cell types: thin-walled, small, isodiametric cells
with large nuclei and dense cytoplasm, typical of intense metabolic activity; and elongated and vacuolated cells, with small
nuclei and less dense cytoplasm. Differentiation of somatic embryos was promoted on MS medium supplemented with activated
charcoal and indole-3-acetyl-l-aspartic acid (IAA-Asp) either with or without 2,4-D. However, no conversion of somatic embryos into plantlets was observed. 相似文献
7.
Jin Cui Jianjun Chen Richard J. Henny 《In vitro cellular & developmental biology. Plant》2009,45(1):34-43
Plant regeneration through direct somatic embryogenesis in Aeschynanthus radicans ‘Mona Lisa’ was achieved in this study. Globular somatic embryos were formed directly from cut edges of leaf explants and
cut ends or on the surface of stem explants 4 wk after culture on Murashige and Skoog (MS) medium supplemented with N-phenyl-N′-1, 2, 3-thiadiazol-5-ylurea (TDZ) with α-naphthalene acetic acid (NAA), TDZ with 2,4-dichlorophenoxyacetic acid (2,4-D),
or 6-benzylaminopurine (BA) or kintin (KN) with 2,4-D. MS medium containing 9.08 μM TDZ and 2.68 μM 2,4-D resulted in 71%
of stem explants producing somatic embryos. In contrast, 40% of leaf explants produced somatic embryos when induced in medium
containing 6.81 μM TDZ and 2.68 μM 2,4-D. Somatic embryos matured, and some germinated into small plants on the initial induction
medium. Up to 64% of stem explants cultured on medium supplemented with 9.08 μM TDZ + 2.68 μM 2,4-D, 36% of leaf explants
cultured on medium containing 6.81 μM TDZ and 2.68 μM 2,4-D had somatic embryo germination before or after transferring onto
MS medium containing 8.88 μM BA and 1.07 μM NAA. Shoots elongated better and roots developed well on MS medium without growth
regulators. Approximately 30–50 plantlets were regenerated from each stem or leaf explant. The regenerated plants grew vigorously
after transplanting to a soil-less substrate in a shaded greenhouse with more than a 98% survival rate. Three months after
their establishment in the shaded greenhouse, 500 plants regenerated from stem explants were morphologically evaluated, from
which five types of variants that had large, orbicular, elliptic, small, and lanceolate leaves were identified. Flow cytometry
analysis of the variants along with the parent showed that they all had one identical peak, indicating that the variant lines,
like the parent, were diploid. The mean nuclear DNA contents of the variant lines and their parent ranged from 4.90 to 4.99 pg
2C−1, which were not significantly different statistically. The results suggest that the regenerated plants have a stable ploidy
level, and the regeneration method established in this study can be used for rapid propagation of ploidy-stable Aeschynanthus radicans. 相似文献
8.
S. Paul A. Dam A. Bhattacharyya T. K. Bandyopadhyay 《Plant Cell, Tissue and Organ Culture》2011,105(2):271-283
A reproducible protocol for direct and indirect somatic embryogenesis was established in a small aromatic tree, Murraya koenigii. Embryogenic callus was obtained from 90% zygotic embryonic axis (ZE) and 70% cotyledon (COT) explants in Murashige and Skoog
(MS) basal medium supplemented with 8.88 μM 6-benzyladenine (BA) and 2.675 μM α-naphthaleneacetic acid (NAA). Globular somatic
embryos were induced and further matured from such embryogenic callus by subsequent culture on the same basal media containing
thidiazuron (TDZ) (2.27–9.08 μM). The highest frequency of somatic embryos (14.58 ± 0.42) was recovered from ZE-derived callus
after 6 weeks. The age and type of explant and concentration of TDZ played an important role in the development of somatic
embryos. Explants excised from 60-day-old seed differentiated from 96.67% of ZE explants and 86.67% from COT explants when
cultured on MS basal medium supplemented with 4.54 and 9.08 μM TDZ, respectively, after 4 weeks. The best result obtained
for the average frequency of somatic embryos (11.28 ± 0.32) was from ZE explants, which was significantly higher than COT
explants (7.34 ± 0.97). Most of the somatic embryos (above 95%), irrespective of their origin, germinated after 4 weeks in
1/2 MS basal media containing 2.32 μM kinetin (KN) and 1.07 μM NAA. Well-rooted plantlets were successfully acclimatized.
Histological analysis and scanning electron micrographs confirmed the initiation, development, and germination of somatic
embryos from both explants. 相似文献
9.
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
10.
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
11.
M. A. K. Azad S. Yokota F. Begum N. Yoshizawa 《In vitro cellular & developmental biology. Plant》2009,45(4):441-449
Somatic embryogenesis and subsequent plant regeneration were established from hypocotyl and internode explants collected from
in vitro-grown seedlings and in vitro-proliferated shoots, respectively. Somatic embryogenesis was significantly influenced by the types of auxin and cytokinin.
Friable calluses with somatic embryos developed well in Murashige and Skoog basal (MS) medium supplemented with 0.8–8.8 μM
6-benzylaminopurine (BA) and 2.0–8.0 μM 2,4-dichlorophexoxyacetic acid (2,4-D) or α-naphthaleneacetic acid (NAA). The maximal
frequency of embryogenic callus and somatic embryo formation were obtained when the MS medium was amended with 8.8 μM BA and
4.0 μM 2,4-D. The best embryo germination occurred in a hormone-free 1/2-MS medium. The highest percentage of shoot proliferation
was observed in embryogenic calluses in MS medium containing 2.0 μM BA and 1.0 μM NAA. In vitro-grown shoots were rooted in MS medium with 0.5–2.0 μM indole-3-butyric acid. Regenerants were transferred to vermiculite and
successfully established under an ex vitro environment in garden soil. 相似文献
12.
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
13.
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
14.
S. Zdravković-Korać D. Ćalić-Dragosavac B. Uzelac D. Janošević S. Budimir B. Vinterhalter D. Vinterhalter 《Plant Cell, Tissue and Organ Culture》2008,94(2):225-231
Somatic embryos of red horse chestnut, derived from cultures maintained through repetitive somatic embryogenesis for a few
years, were subjected to induction of secondary regeneration. The embryos were divided in four classes on the basis of their
size (I-1, II-5, III-10 and IV-30 mm), and sub-cultured on MS media containing 0, 1, 5 or 10 μM kinetin (Kin) or benzyladenine
(BA). The pathway of secondary regeneration, somatic embryogenesis or caulogenesis, depended on the primary somatic embryo
(PSE) stage of development. The embryogenic capacity declined and bud-forming capacity increased with the degree of PSE maturity.
The PSE of the Classes I and II produced only secondary somatic embryos (SSE), the Class III PSE formed both SSE and adventitious
buds, whereas the Class IV PSE developed almost solely adventitious buds. The process of secondary somatic embryogenesis was
most effective in the Class II PSE at 5 μM BA, and the process of adventive organogenesis was most effective in the Class
IV PSE at 10 μM BA. On plant growth regulator (PGR)-free medium, PSE of A. carnea followed the same pattern of adventive regeneration, as those cultured on cytokinin containing media. The cytokinins only
amplified the response, in a certain range of concentrations. BA promoted bud induction at a much higher rate than Kin, while
their embryogenic effect was similar. 相似文献
15.
Liberato Portillo Fernando Santacruz-Ruvalcaba Antonia Gutiérrez-Mora Benjamín Rodríguez-Garay 《In vitro cellular & developmental biology. Plant》2007,43(6):569-575
Somatic embryogenesis was achieved from leaves of Agave tequilana Weber cultivar azul utilizing MS medium supplemented with L2 vitamins and the addition of cytokinins: 6-benzylaminopurine
(BA), 1-phenyl-3(1,2,3-thiadiazol-5-yl)urea (TDZ), 6-(γ-γ-dimethylamino)purine (2ip) and 6-furfurylaminopurine (KIN), combined
with the auxin 2,4-dichlorophenoxyacetic acid (2,4-D). Differences among the six genotypes studied with regard to their embryogenic
response in culture were found. Embryos produced by genotype S3 under a hormone regime of high cytokinin (44.4 to 66.6 μM
BA) compared to auxin (4.5 μM 2,4-D) contained chlorophyll, whereas those produced when auxin was high compared to cytokinin
(9.0 and 13.6 μM 2,4-D and 1.3 and 4.0 μM BA, respectively) were whitish and morphologically similar to their zygotic counterparts.
Somatic embryos matured and germinated after transferring the embryogenic calli to maturation and germination medium without
growth regulators and enriched with organic nitrogen. Microscopic observations demonstrated a unicellular origin for production
of indirect somatic embryos. 相似文献
16.
Konstantin V. Kiselev Anna V. Turlenko Yuri N. Zhuravlev 《Plant Cell, Tissue and Organ Culture》2009,99(2):141-149
A somatic embryogenesis protocol for plant regeneration of northern red oak (Quercus rubra) was established from immature cotyledon explants. Embryogenic callus cultures were induced on Murashige and Skoog medium
(MS) containing 3% sucrose, 0.24% Phytagel™, and various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-d) after 4 weeks of culture in darkness. A higher response (66%) of embryogenic callus was induced on 0.45 μM 2,4-d. Higher numbers of globular- (31), heart- (17), torpedo- (12), and cotyledon-stage (8) embryos per explant were obtained
by culturing embryogenic callus on MS with 3% sucrose, 0.24% Phytagel™, and devoid of growth regulators after 8 weeks culture
in darkness. Continuous sub-culturing of embryogenic callus on medium containing 2,4-d yielded only compact callus. Desiccation of embryos for 3 days in darkness at 25 ± 2°C followed by cold storage at 4°C in
darkness for 8 weeks favored embryo germination and development of plantlets. Cotyledon-stage embryos subjected to desiccation
and chilling treatment cultured on MS with 3% sucrose, 0.24 Phytagel™, 0.44 μM 6-benzylaminopurine (BA), and 0.29 μM gibberellic
acid germinated at a higher frequency (61%) than with 0.44 μM BA alone and control cultures. Germinated plantlets developed
a shoot and root, were acclimatized successfully, and maintained in a growth room for plantlet development. 相似文献
17.
Efficient somatic embryogenesis (SE) and in vitro flowering and fruiting were achieved in Saposhnikovia divaricata (Turcz.) Schischk. Friable embryogenic callus developed from the root, internode, and leaf explants on Murashige and Skoog
medium (MS) with 2.26 μM 2,4-dichlorophenoxyacetic acid (2,4-D), and subsequently developed into somatic embryos on MS medium
containing 4–5% sucrose, 1.74 μM naphthaleneacetic acid (NAA), 4.44 μM 6-benzylaminopurine (BA), and 1.90 μM abscisic acid
(ABA). Then the mature embryos were separated and transferred onto MS with 3% sucrose and 0.6% agar for further development
and conversion to plantlets. In vitro flowering and fruiting were obtained when the subcultures were carried out for over
15 months. Paclobutrazol (PP333) or ethephon (ETH) at low levels promoted flowering significantly. Also, abnormal rootless
somatic embryos of S. divaricata could form flowers and fruits in vitro. 相似文献
18.
Mingliang Chai Yufang Jia Shu Chen Zhongshan Gao Hefei Wang Lulu Liu Peijia Wang Daqiang Hou 《Plant Cell, Tissue and Organ Culture》2011,104(2):187-192
An efficient protocol of callus induction, plant regeneration and long-term maintenance of embryogenic cultures for manilagrass
was developed. Callus induction and embryogenic callus formation were influenced by cytokinins and nodal positions. Murashige
and Skoog (MS) medium with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D), 0.02 mg l−1 kinetin (KT) or 6-benzyladenine (BA) gave the highest frequency for both callus induction and embryogenic callus formation
compared with 0.02 mg l−1 thidiazuron (TDZ) or N6-(2-isopenteny) adenine (2iP). The frequency of callus induction of different nodes (from the first to the sixth node) varied
from 22.5 to 92.1%, and the embryogenic callus formation frequencies ranged from 13.3 to 25.7%. The highest frequencies of
callus induction and embryogenic callus formation (92.1 and 25.7%, respectively) were observed in the fourth node group. During
subculture on callus induction and maintenance medium, somatic embryos formed on the surface of the embryogenic callus. On
regeneration medium, the regeneration rates of embryogenic callus varied from 96.8 to 100% during the 4-year period of subculture.
The results also indicate that preservation of manilagrass callus is stable at low-temperature (4°C) over a period of 11 months.
No significant differences were found in the activities of superoxide dismutase (SOD), peroxidase (POD) and proline content
of the plants regenerated from the 4-year subcultured callus on different regeneration media. 相似文献
19.
P. I. P. Perera V. R. M. Vidhanaarachchi T. R. Gunathilake D. M. D. Yakandawala V. Hocher J. L. Verdeil L. K. Weerakoon 《Plant Cell, Tissue and Organ Culture》2009,99(1):73-81
Coconut is a cross pollinating palm, propagated only by seeds. Tissue culture is the only vegetative propagation method available
for coconut. Consistent callogenesis was obtained by culturing unfertilised ovaries at -4 stage in CRI 72 medium containing
100 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.1% activated charcoal. Callusing was improved by application of 9 μM thidiazuron
(TDZ). Embryogenic calli were subcultured onto somatic embryogenesis induction medium containing 66 μM 2,4-D. Stunted growth
was observed in the somatic embryos after subculture onto CRI 72 medium containing abscisic acid (ABA). Maturation of somatic
embryos could be achieved in Y3 medium without growth regulators. Conversion of somatic embryos was induced by adding gibberellic acid (GA3) to conversion medium containing 5 μM 6-benzyladenine (BA) while 2-isopentyl adenine (2iP) increased the frequency of plant
regeneration. A total of 83 plantlets was produced from 32 cultured ovaries. 相似文献
20.
Varsha Shriram Vinay Kumar Mahadeo G. Shitole 《In vitro cellular & developmental biology. Plant》2008,44(3):186-193
Abstract
Helicteres isora is a medicinal plant effective against asthma, diabetes, hypolipidemia, HIV, polio besides a good source of diosgenin. Seed
dormancy and low natural fruit production rate make this plant a perfect candidate for developing an in vitro regeneration
method. However, to date, no such work has been procured in this plant. An efficient method for plant regeneration via shoot
organogenesis from callus cultures has been developed using nodal explants in H. isora. Murashige and Skoog (MS) media counting 2,4-Dichlorophenoxyacetic acid (2,4-D, 2.26 to 13.57 μM), Indole-3-acetic acid (IAA,
2.85 to 17.13 μM), Indole-3-butyric acid (IBA, 2.46 to 14.70 μM), 6-Benzylaminopurine (BA, 2.22 to 13.32 μM) and Kinetin (Kin,
2.32 to 13.92 μM) either singly or in the following combinations (IAA + BA; IAA + Kin, and BA + Kin) produced granular callus
except BA + Kin which resulted in compact, hard, greenish-white (CHGW) callus. The optimum CHGW callus (2.62 g fresh weight/
explant) was produced on MS media with 13.32 μM BA + 2.32 μM Kin with over 93% callus induction frequency. Optimum shoot organogenesis
(67% frequency) was achieved in CHGW callus with lower level of BA (2.22 μM) and Kin (2.32 μM) and produced 3.2 shoots/0.5 g
callus within 35 d of culture. Microshoots were rooted successfully (62% frequency) after 35 d of culture on 1/2MS containing
4.90 μM IBA and hardened off. Antioxidant enzymes such as catalase, peroxidase, polyphenol oxidase, and biochemical parameters
viz. hydrogen peroxide, reducing and nonreducing sugars, starch, proteins, phenols, and proline contents were studied in regenerating
and nonregenerating CHGW calluses to establish a correlation between these parameters and shoot morphogenesis. All the enzyme
activities and biochemical parameters were found more in regenerating callus than in nonregenerating except phenols. 相似文献