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1.
A regeneration system was developed for Prunus serotina from a juvenile (F) and two mature genotypes (#3 and #4). Adventitious shoots regenerated from leaves of in vitro cultures
on woody plant medium with thidiazuron (TDZ) and naphthaleneacetic acid (NAA). The best regeneration for genotype F (91.4%)
was observed on medium with 9.08 μM TDZ and 1.07 μM NAA. The highest mean number of shoots (8.2) was obtained on medium containing
9.08 μM TDZ and 0.54 μM NAA. Genotype #3 had the highest regeneration (41.7%) with a mean number of shoots (4.8) on 9.08 μM
TDZ and 1.07 μM NAA, whereas genotype #4 had a 38.8% regeneration with a mean of 3.3 shoots. Genotype #4 had the highest mean
number of shoots (4.8) on 4.54 μM TDZ and 1.07 μM NAA. Silver thiosulphate at 60 or 80 μM increased the percent regeneration
of the mature genotypes #3 (75%) and #4 (58%). Adventious shoots were rooted (70–76%) and rooted plantlets survived after
acclimatization to the greenhouse. The effect of kanamycin concentration on adventitious shoot regeneration was also evaluated. 相似文献
2.
Pretreatment in thidiazuron improves the in vitro shoot induction from leaves in Curculigo orchioides Gaertn., an endangered medicinal plant 总被引:1,自引:0,他引:1
T. Dennis Thomas 《Acta Physiologiae Plantarum》2007,29(5):455-461
Leaf regeneration via direct induction of adventitious shoots obtained from an endangered medicinal plant, Curculigo orchioides Gaertn. by pretreating with thidiazuron. C. orchioides is an endangered medicinal herb belonging to the family Hypoxidaceae. Direct inoculation of leaf pieces on MS medium supplemented
with various concentrations of BAP (2–8 μM) or TDZ (2–8 μM) alone or in combination with NAA (0.5 and 1.0 μM) produced low
shoot induction both in terms of % response and number of shoots per explant. Hence, leaf explants were pretreated with 15,
25 or 50 μM thidiazuron (TDZ), for 6, 24 or 48 h with the aim of improving shoot regeneration from cultured explants. After
pretreatment, explants were transferred to an agar solidified MS medium that was supplemented with BAP (4 μM), TDZ (6 μM),
BAP (4 μM) + NAA (1.0 μM), TDZ (6 μM) + NAA (0.5 μM). Control explants were incubated directly on the medium without any pretreatment.
The pretreatment of explants with 15 μM TDZ for 24 h significantly promoted the formation of adventitious shoots and the maximum
response was observed on MS medium supplemented with 6 μM TDZ. In this medium, 96 % cultures responded with an average number
of 16.2 adventitious shoots per explant. The percentage of leaf explants producing shoots and the average number of shoots
per explant were significantly improved when TDZ pretreated leaves were cultured onto MS medium supplemented with BAP or TDZ
alone or in combination with NAA. The rooted plantlets were successfully transplanted to soil with 90% success. The present
investigation indicated the stimulatory role of TDZ pretreatment in regulating shoot regeneration from leaf explants of C. orchioides. 相似文献
3.
Guohua Ma Jaime A. Teixeira da Silva Jinfeng Lü Xinhua Zhang Jietang Zhao 《Plant Cell, Tissue and Organ Culture》2011,105(3):355-361
An efficient propagation and regeneration system via direct shoot organogenesis for an endangered species, Metabriggsia ovalifolia, was established. High activity cytokinins [6-benzyladeneine (BA) and thidiazuron (TDZ)] and low activity auxins [α-naphthaleneacetic
acid (NAA), indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA)] could directly induce adventitious shoots from leaf
or petiole explants within 5 weeks. Cytokinins (TDZ or BA) combined with auxin (NAA) in the induction media induced more adventitious
shoots than when auxins or cytokinins were used alone. Adventitious shoots could be induced and also mass-propagated on media
containing 2.5–5.0 μM TDZ (or BA) and 0.25–0.5 μM NAA. Adventitious roots differentiated at the proximal end of shoots on
rooting media containing half-strength MS salts and 0.5 μM IBA, 0.5 μM NAA, 0.1% activated charcoal or no plant growth regulators.
Over 90% of plantlets survived following acclimatization and transfer to a potting mixture (1:1, sand:vermiculite) in basins. 相似文献
4.
M. Arshad J. Silvestre G. Merlina C. Dumat E. Pinelli J. Kallerhoff 《Plant Cell, Tissue and Organ Culture》2012,108(2):315-322
Shoot organogenesis from mature leaf tissues of two scented Pelargonium capitatum cultivars, ‘Attar of Roses’ and ‘Atomic Snowflake’, grown in the greenhouse, were optimized in the presence of thidiazuron
(TDZ). The protocol involved preculture of leaf sections on basal Murashige and Skoog (MS) medium supplemented with 10 μM
TDZ, 4.4 μM of 6-benzyladenine (BA) and 5.4 μM α-naphtaleneacetic acid (NAA) for a period of 2 weeks and followed by subculture
of explants to a fresh medium containing 4.4 μM BA and 5.4 μM NAA. Frequency of regeneration reached approximately 93% for
both cultivars, with the induction of more than 100 shoots per explant. Regenerated plantlets were rooted on half-strength
MS medium supplemented with 4.4 mM sucrose and 8.6 μM of Indole-3-acetic acid (IAA). All regenerated shoots from both cultivars
developed roots when transferred to organic soil mix, acclimatized, and successfully transferred to greenhouse conditions.
When regenerated shoots were transferred to hydroponic conditions, frequency of survival was 76.2 and 61.9% for ‘Attar of
Roses’ and ‘Atomic Snowflake’, respectively. 相似文献
5.
B. Wang D. X. Peng Z. X. Sun N. Zhang S. M. Gao 《In vitro cellular & developmental biology. Plant》2008,44(2):105-111
Ramie [Boehmeria nivea (L.) Gaud] is one of the most important perennial fiber crops in China. In vitro tissue culture of ramie could serve as an important means for its improvement through genetic transformation. To improve
the regeneration capacity of ramie, the effects on plant regeneration of donor plant age, basal medium, plant growth regulators,
and culture conditions were evaluated using explants derived from the cotyledon, hypocotyl, leaf, petiole, and stem of ramie
seedlings. Cotyledons and hypocotyls excised from 4-d-old seedlings and leaves and petioles and stems from 15-d-old seedlings
were optimal explants. The highest regeneration efficiency was obtained on Murashige and Skoog salts with Gamborg’s B5 vitamins basal medium containing 2.27 μM thidiazuron (TDZ) and 0.054 μM naphthaleneacetic acid (NAA) for the five explant
types tested. A photoperiod of 16:8 h (light/dark) was found to be superior than continuous darkness for regeneration of ramie
using TDZ. The regenerated shoots were transferred to hormone-free medium for shoot elongation and successfully rooted on
half-strength Murashige and Skoog supplemented with 0.134 μM NAA. The rooted plantlets with four to five leaves were transplanted
to greenhouse for further growth. 相似文献
6.
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
7.
Houcheng Zhou Ming Li Xia Zhao Xiucai Fan Aiguang Guo 《Plant Cell, Tissue and Organ Culture》2010,101(1):79-87
A complete protocol for adventitious shoot regeneration was developed from the leaves of peach rootstock ‘Nemaguard’(Prunus persica × P. davidiana) grown in vitro. Shoot explants were cultured in vitro in Murashige and Skoog medium supplemented with 3.55 μM 6-benzyladenine
and 7.38 μM indole-3-butyric acid (IBA). Non-expanded leaves along with their petioles from 3-week-old in vitro-grown shoots
were used as explants. Regeneration percentage was influenced by plant growth regulators, basal medium, explant type, dark
period, and gelling agents. Optimal regeneration was observed with leaf explants wounded by transverse cuts twice along the
midrib and first incubated with abaxial surfaces facing upward in the dark for 3 weeks, and then transferred to the light
and cultured with the adaxial side in contact with regeneration medium, as seen on 1/2 MS, woody plant medium or Schenk and
Hildebrandt medium supplemented with 9.08 μM thidiazuron, 0.54 μM IBA and 0.25% agar. This produced the highest regeneration
percentage at 71.7% and a mean of 5.74 ± 3.24 shoots on 1/2 MS medium. Adventitious shoots were rooted (98.3–100%) and rooted
plantlets survived after acclimatization to the greenhouse. 相似文献
8.
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
9.
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
10.
Summary Tennessee coneflower [Echinacea tennesseensis (Beadle) Small] was regenerated from flower stalks, leaf sections from flowering plants, and hypocotyls and cotyledons from
seedlings. Murashige and Skoog medium (MS) supplemented with naphthaleneacetic acid (NAA) at 0.54 μM and thidiazuron (TDZ) at 22.7 μM yielded the most shoots per leaf explant. NAA and 6-benzylaminopurine concentrations for optimal shoot regeneration from
leaf, flower stalk, cotyledon and hypocotyl explants in MS media were 0.54 and 24.6μM, respectively. All explant types generated shoots; however, those derived from leaves and flower stalks produced the highest
number of shoots per explant and highest percentage of explants with shoots. Explants cultured on media containing high levels
of NAA (5.4–27 μM) formed calluses but no adventitious shoot. Leaf explants responded to a wider range of NAA concentrations than the other
explant types but shoots generated from flower stalks grew the fastest. While all cytokinins tested increased the number of
shoots per explant, the number of shoots in media containing TDZ was increased by nearly threefold. Regenerated shoots from
all explant types cultured on MS medium supplemented with 0.25 μM indole-3-butyric acid initiated roots within 4 wk; NAA was not effective for root induction. All vernalized plantlets developed
into plants that were morphologically identical to the source material. 相似文献
11.
Qin-Mei Wang Feng-Zhan Gao Xiang Gao Fan-Yu Zou Xin Sui Meng Wang Yue-Jun Hui Li Wang 《Plant Cell, Tissue and Organ Culture》2012,109(2):191-200
An efficient in vitro micropropagation system for Clivia miniata Regel was developed using basal tissues of young petals and young ovaries as explants. For callus induction, explants were
incubated on Murashige and Skoog (MS) medium containing either 2.22 μM 6-benzyladenine (BA) and 4.52 μM 2,4-dichlorophenoxyacetic
acid (2,4-D) or 4.44 μM BA, 5.37 μM α-naphthaleneacetic acid (NAA), and 9.05 μM 2,4-D. Moreover, callus was induced from young
ovaries when these were incubated on MS medium containing 8.88 μM BA, 10.74 μM NAA, and 9.05 or 18.10 μM 2,4-D. Subsequently,
callus was transferred to MS medium supplemented with kinetin (KT) and NAA for shoot organogenesis. Frequency of shoot regeneration
from petal-derived callus was highest when callus was transferred to medium containing 2.69 μM NAA with either 9.29 or 13.94 μM
KT. Shoot regeneration frequency from ovary-derived callus was highest when this callus was transferred to medium containing
9.29 μM KT and 10.74 μM NAA. Overall, different explant types exhibited different organogenic capacities wherein, young petals
had higher shoot regeneration frequencies than young ovaries. The highest rooting frequency (98.25 ± 3.04%) was obtained when
shoots were transferred to half-strength MS medium without plant growth regulators. Regenerated plantlets were transplanted
to soil mix and acclimatized, yielding a 96.80% survival frequency. Only 0.6% of regenerated plantlets exhibited morphological
changes. The diploid status (2n = 22) of regenerated plantlets was determined using chromosome counts of root-tips. Moreover, inter-simple sequence repeats
were used to assess the genetic fidelity of regenerated plantlets. Overall, regenerated plants shared 90.5–100.0% genetic
similarities with mother plants and 89.0–100.0% similarities with each other. 相似文献
12.
Dormant buds from a mature tree of Populus tremula ‘Erecta’ were incubated on a Murashige and Skoog (MS) medium supplemented with 1.0 μM thidiazuron (TDZ). Induced shoots were
then proliferated on medium of MS or Woody Plant Medium (WPM), or Driver and Kuniyuki Walnut (DKW) supplemented with varying
levels of benzyladenine (BA). Overall, shoots grown on MS medium supplemented with 1.25–2.5 μM BA exhibited the highest frequency
of shoot proliferation (>95%) and more than 60% of responding explants produced more than five shoots per explant. Shoot organogenesis
was induced from both leaf and petiole explants incubated on WPM medium containing BA, or TDZ, or zeatin. Among the different
cytokinins tested, zeatin induced the highest frequency (average 72.1%) of shoot organogenesis. None of explants survived
on media containing no cytokinins within 6–8 weeks following culture. Overall, a higher frequency of shoot regeneration was
obtained from petioles than from leaf explants. The highest frequency of regeneration was achieved when petioles were incubated
on WPM containing 10–20 μM zeatin. Addition of naphthaleneacetic acid (NAA) did not have a significant effect on shoot regeneration
in all treatments. Shoot organogenesis was directly induced from petiole explants without intervening callus. Regenerated
shoots were easily rooted on all tested media supplemented with 0.5 μM NAA. Rooted plants were transferred to potting mix
and grown in the greenhouse. 相似文献
13.
G. G Ning S. P Bai M. Z Bao L. Liu 《In vitro cellular & developmental biology. Plant》2007,43(2):95-100
Using immature embryos and cotyledons as explants, a successful system to culture immature embryos and induce direct regeneration
from cotyledons was established for Prunus mume “Xuemei”. For immature embryo culture, a high frequency of plantlet formation (89.5%) from the embryonic axis was obtained
using half-strength Murashige and Skoog (1/2 MS) medium supplemented with 13.2 μM 6-benzyladenine (BA) and 2.7 μM 1-naphthaleneacetic
(NAA). Shoots formed directly from cotyledons with the embryo axis intact when explants were cultured on 1/2 MS medium containing
2.2 μM BA with different combinations of NAA (2.7, 5.4 μM) and indole-3-butyric acid (IBA) (0, 2.5, 5.0 μM). Better results
were achieved when the embryonic axis was removed from the cotyledons and cultured on 1/2 MS medium supplement with 13.2 μM
BA, 2.7 μM NAA or 2.2 μM BA, 2.2 μM thidiazuron (TDZ), and 2.7 μM NAA, respectively. Regenerated shoots were successfully
rooted on 1/2 MS or Woody Plant medium (WPM) supplemented with 2.5–5.0 μM IBA. The effect of the embryonic axis, BA, and TDZ
on cotyledon regeneration was investigated in detail. Rooted plantlets were transferred to soil successfully. 相似文献
14.
In vitro regeneration of Parkia timoriana (DC.) Merr. has been achieved using cotyledonary node explants. The ability to produce multiple shoots has been evaluated
using semi-solid Murashige and Skoog (MS) basal medium and Gamborg’s B-5 basal medium supplemented with various concentrations
of α-naphthalene acetic acid (NAA) and 6-benzylaminopurine (BA) either in single or in combinations. The explants cultured
in MS medium supplemented with combinations of 2.7 μM NAA and 11 μM BA showed the maximum frequency of multiple shoots (96.66%)
formation and number of shoots per explants (6.60), respectively. For rooting, full and half strength MS medium supplemented
with various concentrations of indole-3-butyric acid (IBA) and NAA were studied and the highest number of root formation was
observed in full-strength MS supplemented with 9.8 μM IBA. Using Agrobacterium tumefaciens strain EHA105 pCAMBIA2301 various optimum conditions for efficient transformation were determined by recording the percentage
of GUS+ explants. Following the optimized conditions, the co-cultured explants were cultured on semi-solid shoot regeneration medium
containing MS medium + 2.7 μM NAA + 11 μM BA + 100 mg/l kanamycin + 500 mg/l cefotaxime. After 8 weeks of culture, the regenerated
shoots were rooted in rooting medium (RM) containing MS medium + 9.8 μM indole-3-butyric acid (IBA), 3% sucrose, 7.5 mg/l
kanamycin and 500 mg/l cefotaxime. Successful transformation was confirmed by histochemical GUS activity of the regenerated
shoots, nptII gene PCR analyses of the regenerated kanamycin resistant plantlets and Southern analysis of putative transgenic PCR+ plants. 相似文献
15.
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
16.
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
17.
L. Burdyn C. Luna J. Tarracó P. Sansberro N. Dudit A. Conzález L. Mrocinski 《In vitro cellular & developmental biology. Plant》2006,42(3):235-239
Summary Adventitious bud regeneration from leaf and internode explants of Aloysia polystachya was achieved. Shoots from nodal segments grown in vitro were cut into pieces and used as sources of explants. Organogenesis was induced from both explants cultured on quarter-strength
Murashige and Skoog (MS) semisolid medium (plus sucrose 5 g l−1) containing different combinations of 6-benzyladenine (BA) and α-naphthaleneacetic acid (NAA) under 116 μmol m−2 s−1 photosynthetic photon flux density (PPFD), 14-h photoperiod, and at a temperature of 27±2°C. The type of explant markedly
influenced organogenesis and growth of the regenerated shoots. The regeneration frequencies were higher with leaf explants,
while the number of shoots formed per responsive explant was greater with internode explants. However, the growth of regenerated
shoots from internodes was seriously affected by vitrification. The number of shoots produced per responsive leaf explant
increased from one to seven as the percentage of leaf explants producing shoots increased from 20 to more than 80%. NAA at
0.05 μM in combination with BA at 0.5μM induced the highest regeneration rate (87±8.8%) after 20 d of culture, yielding 5.9±0.8 shoots per responsive leaf explant.
Histological examination confirmed the occurrence of direct organogenesis. The regenerated shoots from the best induction
treatment were transferred to a fresh medium without plant growth regulators for 30 d. Finally, the elongated shoots were
rooted by pre-treatment in an aqueous solution of NAA at 500 μM for 2 h and transferred to 1/4 MS. All plantlets raised in vitro were phenotypically normal and successfully hardened to ex vitro conditions. An experimental field plot with 2-yr-old in vitro-regenerated plants was established. 相似文献
18.
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
19.
Attempts were made to study the effect of thidiazuron (TDZ) on adventitious shoot induction and plant development in Paulownia tomentosa explants derived from mature trees. Media with different concentrations of TDZ in combination with an auxin were used to
induce adventitious shoot-buds in two explant types: basal leaf halves with the petiole attached (leaf explant) and intact
petioles. Optimal shoot regeneration was obtained in leaf explants cultured on induction medium containing TDZ (22.7 or 27.3 μM)
in combination with 2.9 μM indole-3-acetic acid (IAA) for 2 weeks, and subsequent culture in TDZ-free shoot development medium
including 0.44 μM BA for a further 4-week period. The addition of IAA to the TDZ induction medium enhanced the shoot-forming
capacity of explants. The caulogenic response varied significantly with the position of the explant along the shoot axis.
The highest regeneration potential (85–87%) and shoot number (up to 17.6 shoots/explant) were obtained in leaf explants harvested
from the most apical node exhibiting unfolded leaves (node 1). An analogous trend was also observed in intact petiole explants,
although shoot regeneration ability was considerably lower, with values ranging from 15% for petioles isolated from node 1
to 5% for those of nodes 2 and 3. Shoot formation capacity was influenced by the genotype, with regeneration frequencies ranging
from 50% to 70%. It was possible to root elongated shoots (20 mm) in basal medium without growth regulators; however, rooting
frequency was significantly increased up to 90% by a 7-day treatment with 0.5 μM indole-3-butyric acid, regardless of the
previous culture period in shoot development medium (4 or 8 weeks). Shoot quality of rooted plantlets was improved not only
by IBA treatment but also by using material derived from the 4-week culture period. Regenerated plantlets were successfully
acclimatized in the greenhouse 8 weeks after transplanting. 相似文献
20.
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