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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.
Internode explants collected from in vitro grown shoots of two clones of Fagus sylvatica L. (European beech) and five clones of F. orientalis Lipski (Oriental beech) were used to evaluate their bud regeneration capacity. Adventitious shoot-buds formed on callus,
which developed from internode segments cultured in a Woody Plant Medium supplemented with different concentrations of either
thidiazuron (TDZ) or benzyladenine (BA). After 4 weeks of culture on induction media, the explants were transferred to a proliferation
medium supplemented with 2.2 μM BA, 9.1 μM zeatin and 2.9 μM indole-3-acetic acid (IAA) for another 8 weeks. Medium containing
TDZ was much more efficient than medium containing BA in inducing adventitious buds, the optimal TDZ concentration being 4.5
μM and the optimal BA concentration 17.8 μM. Genotypic variation in shoot regeneration capacity was observed among the two
Fagus species and between clones within each species, with a significant interaction between TDZ concentration and genotype regarding
mean bud number. Thidiazuron induction medium supplemented with a range of individual auxins was investigated, and it was
found that IAA or indole-3-butyric acid at 2.9 μM enhanced the bud forming capacity of explants. Morphogenic response varied
significantly with the position of the internode along the stem. The highest regeneration potential was obtained from apical
internodes, while those distal to the apex were the least productive. Elongated shoots of adventitious origin can be readily
proliferated by axillary branching.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
3.
In vitro propagation of northern red oak (Quercus rubra) shoots was successful from cotyledonary node explants excised from 8-wk-old in vitro grown seedlings. Initially, four shoots per explant were obtained on Murashige and Skoog (MS) medium supplemented with 4.4 μM
6-benzylaminopurine (BA), 0.45 μM thidiazuron (TDZ), and 500 mg l−1 casein hydrolysate (CH) with a regeneration frequency of 64.7% after 3 wk. Subculturing explants (after harvesting shoots)
to fresh treatment medium significantly increased shoot bud regeneration (16.6 buds per explant), but the buds failed to develop
into shoots. A higher percentage (73.3%) of the explants regenerated four shoots per explant on woody plant medium (WPM) supplemented
with 4.4 μM BA, 0.29 μM gibberellic acid (GA3), and 500 mg l−1 CH after 3 wk. Explants subcultured to fresh treatment medium after harvesting shoots significantly increased shoot regeneration
(16 shoots per explant). Shoot elongation was achieved (4 cm) when shoots were excised and cultured on WPM supplemented with
0.44 μM BA and 0.29 μM GA3. In vitro regenerated shoots were rooted on WPM supplemented with 4.9 μM indole-3-butyric acid. A higher percentage regeneration response
and shoot numbers per explant were recorded on WPM supplemented with BA and GA3, than on MS medium containing BA and TDZ. Lower concentrations of BA and GA3 were required for shoot elongation and prevention of shoot tip necrosis. Each cotyledonary node yielded approximately 20
shoots within 12 wk. Rooted plantlets were successfully acclimatized. 相似文献
4.
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
5.
Summary Protocols for both axillary bud proliferation and shoot organogenesis of Euphorbia pulchurrima Winter RoseTM were developed using terminal buds and leaf tissues. Greenhouse-grown terminal buds were placed on Murashige-Skoog (MS) basal
medium supplemented with various concentrations of either benzlyaminopurine (BA) or thidiazuron (TDZ). Explants produced the
greatest number of axillary buds on media containing between 2.2 and 8.8 μM BA. The number of explants that produced axillary buds increased with increasing BA concentration. TDZ at concentrations
between 2.3 and 23.0 μM caused hyperhydricity of shoots and were not effective in promoting shoot proliferation. The most calluses and shoots were
produced from leaf midvein sections from in vitro grown plants placed on the medium containing 8.8–13.3 μM BA and 17.1 μM indole-3-acetic acid (IAA) for 1 mo. before transferring to the medium containing only BA. Adventitious buds were produced
only from red-pigmented callus, and explants that produced callus continued to produce adventitious shoots in the presence
of IAA. Five-mo.-old shoots derived from shoot culture or organogenesis rooted readily in artificial soil with or without
treatment with indolebutyric acid, and were acclimatized in the greenhouse. 相似文献
6.
Summary A protocol has been developed for high-frequency shoot regeneration and plant establishment of Tylophora indica from petiole-derived callus. Optimal callus was developed from petiole explants on Murashige and Skoog basal medium supplemented
with 10μM2,4-dichlorophenoxyacetic acid +2,5μM thidiazuron (TDZ). Adventitious shoot induction was achieved from the surface of the callus after transferring onto shoot
induction medium. The highest rate (90%) of shoot multiplication was achieved on MS medium containing 2.5μM TDZ. Individual elongated shoots were rooted best on halfstrength MS medium containing 0.5μM indole-3-butyric acid (IBA). When the basal cut ends of the in vitro-regenerated shoots were dipped in 150μM IBA for 30 min followed by transplantation in plastic pots containing sterile vermiculite, a mean of 4.1 roots per shoot
developed. The in vitro-raised plantlets with well-developed shoot and roots were successfully established in earthen pots containing garden soil
and grown in a greenhouse with 100% survival. Four months after transfer to pots, the performance of in vitro-propagated plants of T. indica was evaluated on the basis of selected physiological parameters and compared with ex vitro plants of the same age. 相似文献
7.
A simple and rapid method for multiple shoot formation in vitro from immature embryo axis explants of Carica papaya L. cvs. Honey Dew, Washington and Co2 is described. Multiple shoot regeneration was achieved by culture of the explants on
modified Murashige and Skoog (MS) medium supplemented either with thidiazuron (TDZ; 0.45–22.7 μM) or a combination of benzylaminopurine
(BAP; 0.2 – 8.84 μM) and naphthalene acetic acid (NAA; 0.5 – 2.64 μM). Highest frequency of shoot regeneration occurred on
medium supplemented either with 2.25 μM TDZ or a combination of BAP (4.4 μM) and NAA (0.5 μM). Composition of the basal media
influenced the frequency of multiple shoot initiation. Stunted shoots regenerated at 4.5 μM and higher concentrations of TDZ.
Such shoots could, however, be elongated by transfer to medium containing 5.7 μM GA3. Rooting of the regenerated shoots was achieved in presence of indolebutyric acid (IBA; 4.92 – 19.68 μM), however, least
response was in presence of 14.7 μM IBA. Rooted plants were hardened and transferred to pots.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
S. C. Debnath 《In vitro cellular & developmental biology. Plant》2009,45(2):122-128
An efficient system to regenerate shoots on excised leaves of greenhouse-grown wild lowbush blueberry (Vaccinium angustifolium Ait.) was developed in vitro. The effect of thidiazuron (TDZ) on adventitious bud and shoot formation from apical, medial, and basal segments of the leaves
was tested. Leaf cultures produced multiple buds and shoots with or without an intermediary callus phase on 2.3–4.5 μM TDZ
within 6 wk of culture initiation. The greatest shoot regeneration came from young expanding basal leaf segments positioned
with the adaxial side touching the culture medium and maintained for 2 wk in darkness. Callus development and shoot regeneration
depended not only on the polarity of the explants but also on the genotype of the clone that supplied the explant material.
TDZ-initiated cultures were transferred to medium containing 2.3–4.6 μM zeatin and produced usable shoots after one additional
subculture. Elongated shoots were dipped in 39.4 mM indole-3-butyric acid powder and planted on a peat:perlite soilless medium
at a ratio of 3:2 (v/v), which yielded an 80–90% rooting efficiency. The plantlets were acclimatized and eventually established in the greenhouse
with 75–85% survival. 相似文献
9.
Summary
In vitro propagation of Pelecyphora aselliformis, a Mexican cactus which is considered rare and is highly valued in the commercial market, was initiated using seeds as explants.
The longitudinal explants from seedlings germinated in vitro were cultivated on Murashige and Skoog medium containing 8.8 μM benzyladenine (BA) or 4.6 μM kinetin at pH 7.0. After 120 d, each explant gave rise to five shoots and this number of shoots increased 20–25% after subculture.
The hyperhydricity was similar in both media, but callus formation was lower on the medium with BA. The shoot development,
in terms of epicotyl length, and fresh and dry weight after 6 wk, was also recorded. The epicotyl length was similar on shoot-forming
media but the quality of shoots was better on media containing BA. In about 1 yr, 500–600 well-defined shoots were obtained.
The rooting of shoots was very slow and a vigorous radical system was observed after 1 yr of culture. 相似文献
10.
A simple, high-frequency and reproducible protocol for induction of adventitious shoot buds and plant regeneration from leaf-disc
cultures of Jatropha curcas L. has been developed. Adventitious shoot buds were induced from very young leaf explants of in vitro germinated seedlings
as well as mature field-grown plants cultured on Murashige and Skoog’s (MS) medium supplemented with thidiazuron (TDZ) (2.27 μM),
6-benzylaminopurine (BA) (2.22 μM) and indole-3-butyric acid (IBA) (0.49 μM). The presence of TDZ in the induction medium
has greater influence on the induction of adventitious shoot buds, whereas BA in the absence of TDZ promoted callus induction
rather than shoot buds. Induced shoot buds were multiplied and elongated into shoots following transfer to the MS medium supplemented
with BA (4.44 μM), kinetin (Kn) (2.33 μM), indole-3-acetic acid (IAA) (1.43 μM), and gibberellic acid (GA3) (0.72 μM). Well-developed shoots were rooted on MS medium supplemented with IBA (0.5 μM) after 30 days. Regenerated plants
after 2 months of acclimatization were successfully transferred to the field without visible morphological variation. This
protocol might find use in mass production of true-to-type plants and in production of transgenic plants through Agrobacterium/biolistic-mediated transformation. 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.
A novel protocol for callus-mediated shoot regeneration was established for an important medicinal and ornamental plant native
to South China, Curcuma kwangsiensis, using shoot base sections excised from seedlings in vitro as explant sources. The frequency of callus formation reached
91% for explants cultured on MS medium containing 1.4 μM TDZ, 4.4 μM BA and 2.3 μM 2,4-D. 8.2 shoots per callus was achieved
on MS medium supplemented with 1.4 μM TDZ, 17.8 μM BA and 2.7 μM NAA. Single shoots transferred into MS medium free of plant
growth regulator rooted well. Regenerated plants acclimatized ex vitro at 100%, and grew vigorously under shaded greenhouse
conditions. 相似文献
13.
Kottackal Poulose Martin A. K. Pradeep Joseph Madassery 《Acta Physiologiae Plantarum》2011,33(4):1141-1148
Trichopus zeylanicus subsp. travancoricus (known as Arogyapacha), an endangered ethnomedicinal plant of the Western Ghats of South India, serves as the major source
of the commercial drug Jeevani. The present study established a long-term high frequency in vitro propagation protocol for Arogyapacha. Callus obtained from
the branch–petiole explants cultured on Murashige and Skoog (MS) medium with 4.5 μM 2,4-dichlorophenoxyacetic acid upon subculture
to medium with different concentrations of 6-benzyladenine (BA) either alone or in combination with an auxin favoured shoot
morphogenesis. Medium with 13.3 μM BA alone facilitated high frequency shoot bud (mean of 93.2) formation. Medium with lower
concentrations of BA (4.4, 6.6 and 8.8 μM) alone or in combination with lower concentration of α-naphthaleneacetic acid (NAA)
or indole-3-butyric acid (IBA) favoured better shoot growth than 13.3 μM BA containing medium, but with reduced number of
shoot buds. Subsequent cultures on medium with lower concentrations of BA and also on MS basal media facilitated shoot formation
as well as growth of shoots. The shoot regeneration potential showed no decline up to 5 years. Culture of the in vitro-derived
whole branch–leaf explants on MS basal medium developed shoots directly from the node. On medium with 19.6 μM IBA, the whole
branch–leaf explants induced nodular callus from the node, which developed shoots later. Subsequent cultures on medium with
BA exhibited high frequency shoot formation. The transfer of shoots after 10–15 days culture on half-strength MS medium containing
2.7 μM NAA to half-strength basal medium induced a mean of 11.3 roots. Field survival of plantlets relied on the soil mix:
a 1:4 ratio of sand and red-soil exhibited the highest plantlets survival (86.6%). RAPD profile of the source plant and plants
regenerated from calli after 4 years showed no polymorphism. The established plantlets with morpho-floral features similar
to that of the source plants flowered normally and set fruits. 相似文献
14.
Wenhao Dai Yuanjie Su Cielo Castillo Olivier Beslot 《Plant Cell, Tissue and Organ Culture》2011,104(2):257-262
Shoots were regenerated from in vitro leaf tissues of two genotypes of Viburnum dentatum, a popular shrub species for landscape use. Adventitious shoots were induced when leaf tissues were cultured on woody plant
medium (WPM) supplemented with either benzyladenine (BA) or thidiazuron (TDZ). Effects of cytokinin concentration, indole-3-butyric
acid (IBA), and dark treatment on shoot regeneration were investigated. Dark treatment for the first 4 weeks of leaf explants
cultured in the regeneration medium significantly increased the frequency of regeneration. The highest frequency of shoot
regeneration (70%) for ‘Synnesvedt’ was obtained when leaf tissues were cultured in the medium with 40 μM BA or 8 μM TDZ with
4 weeks dark treatment. The highest frequency of shoot regeneration (90%) for ‘MN34’ was found in the 4 μM TDZ medium with
4 weeks dark treatment. Addition of IBA significantly enhanced shoot regeneration. Ethyl methanesulfonate (EMS) treatment
inhibited callus proliferation, particularly in the early stage of callus recovery; however, no significant difference in
shoot regeneration among different treatments was observed, indicating that the inhibitory effect of EMS was minimal after
calluses re-acquired their capacity to grow and regenerate in the regular medium. Regenerated shoots (>1.5 cm) were rooted
in the half-strength MS medium containing 5-10 μM IBA or naphthalene acetic acid (NAA). Rooted plants were transferred to
the potting medium and grown in the greenhouse. 相似文献
15.
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
16.
Summary A protocol for in vitro propagation using direct induction of shoot buds from leaf explants of in vitro-raised shoots of Rosa damascena var. Jwala is reported. The present study is the first report on direct shoot regeneration in scented roses. Elite plants
raised from nodal explants and maintained for over 2yr in vitro on a static liquid shoot multiplication Murashige and Skoog (MS) medium supplemented with 5.0 μM benzyladenine (BA) and 3% sucrose were used. Petioles from fully developed young leaves, obtained after 4 wk of pruning of
old shoots, were found to be ideal for regeneration of shoots. Initially the explants were cultured in an induction medium
[half-strength MS+3% sucrose+6.8μM thidiazuron+0.27 μM α-naphthaleneacetic acid (NAA)+17.7 μM AgNO3] and subsequently transferred to the regeneration medium (MS+2.25 μM BA+0.054 μM NAA) after 7, 14, 21, 28, and 35d. The highest shoot regeneration response (69%) was recorded when shoots were kept in the
induction medium for 21 d and later transferred to regeneration medium. Histological studies revealed direct formation of
shoot buds without the intervening callus phase. In vitro rooting of micro-shoots was accomplished within 2wk on half-strength MS liquid medium supplemented with 10.0 μM IBA and 3% sucrose for 1 wk in the dark and later transferred to hormone-free medium and kept in the light. Plantlets, remaining
in the latter medium for 5–6 wk when transferred to soil, showed 90% survival. 相似文献
17.
Summary Establishment of fast-growing, highly regenerable callus cultures was examined in Muscari armeniacum Leichtl. ex Bak. in order to develop an efficient genetic transformation system. High-frequency callus formation was obtained
from leaf explants of cv. Blue Pearl on media containing 2,4-dichlorophenoxyacetic acid (2,4-D), α-naphthaleneacetic acid
(NAA) or 4-amino-3,5,6-trichloropicolinic acid (picloram, PIC). Fast-growing, yellowish nodular callus lines and white friable
callus lines containing a few somatic embryos were established on initiation medium supplemented with 4.5 μM 2,4-D and with 54 μM NAA, respectively. The yellowish nodular calluses vigorously produced shoot buds after transfer to media containing 0.44–44
μM 6-benzyladenine (BA), whereas the white friable calluses produced numerous somatic embryos upon transfer to plant growth
regulator-free (PGR-F) medium. Histological observation of shoot buds and somatic embryos indicated that the former consisted
of an apparent shoot meristem and several leaf primordia, and the latter had two distinct meristematic regions, corresponding
to shoot and root meristems. Both shoot buds and somatic embryos developed into complete plantlets on PGR-F medium. Regenerated
plants showed no observable morphological alterations. High proliferation and regeneration ability of these calluses, were
maintained for over 2 yr. 相似文献
18.
Jianming Gao Jinzhi Li Caibo Luo Liang Yin Shengchun Li Guangxiao Yang Guangyuan He 《Molecular biology reports》2011,38(2):1413-1417
To establish a successful in vitro plant regeneration system in Alternanthera philoxeroides (Mart.) Griseb, an orthogonal design was used to investigate the effects of three factors (plant growth regulators, explant
types and dark treatment in initial-stage), each having three levels. The effects of these factors and levels on callus induction
and shoot regeneration were quantitatively evaluated by analysis of variance. The experimental results showed that the callus
induction was significantly affected by 2, 4-dichlorophenoxyacetic acid (2, 4-D), and shoot differentiation from subcultured
pieces of callus was enhanced mostly by dark treatment in initial-stage. The optimal conditions for callus induction are obtained
from the stem explants cultured on semi-solid Murashige and Skoog (MS) medium plus 2.2 μM BA and 2.2 μM 2, 4-D, with 20 days
dark treatment in initial-stage. The highest frequency of shoot regeneration is obtained from the calli cultured on semi-solid
MS medium plus 8.8 μM BA, without dark treatment in initial-stage. 相似文献
19.
Leaf explants of Jatropha curcas cultured on Murashige and Skoog’s (MS) medium supplemented with thidiazuron (TDZ; 0.90 μM) in combination with indole-3-butyric
acid (IBA; 0.98μM) produced adventitious shoot buds directly on the surface of the explants without formation of intervening
callus while shoot bud formation was accompanied with callus formation on medium supplemented with 6-benzylaminopurine (BAP;
13.3 μM) and IBA (2.46 μM). TDZ treatment resulted in more than twice higher rate of shoot bud induction than BAP. Shoot buds
were multiplied and elongated following repeated transfers to medium containing BAP (2.22 μM) and gibberellic acid (GA3; 1.44 μM). The effect of copper sulphate on differentiation of shoot buds from leaf segments was also investigated. Both
shoot induction and multiplication media were supplemented with different levels of CuSO4 (0–5 μM). Significant improvement in shoot bud induction was observed when the concentration of CuSO4 was increased to 10 times the normal MS level. Healthy elongated shoots were rooted on half strength MS medium supplemented
with IBA (2.46 μM). Rooted plantlets were transferred to field and survived. Histological analysis revealed direct formation
of shoot buds from leaf explants. 相似文献
20.
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