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1.
This report deals with micropropagation of the critically endangered and endemic Turkish shrub, Thermopsis turcica using callus, root and cotyledonary explants. Callus cultures were initiated from root and cotyledon explants on MS medium
supplemented with 0.5–20 μM NAA or 2,4-D. The root explants were found to be better in terms of quick responding and callusing
percentages as compared to the cotyledons. Organogenic callus production with adventitious roots and shoots were obtained
on MS medium with only NAA. The calli obtained with NAA, root and cotyledonary explants were cultured with BA and kinetin
(2–8 μM) alone or in combination with a low level (0.5 μM) of 2,4-D or NAA. The best regeneration of shoots from root explants
was observed on hormone-free MS medium. NAA with BA or kinetin in the medium improved shoot induction from the calli obtained
with NAA. Maximum percentage of shoots (93.3%), maximum number of shoots (6.2) and maximun length of shoots (8.22 cm) were
achieved from cotyledonary explants at 4 μM BA and 0.5 μM NAA. The presence of 0.5 μM or higher levels of 2,4-D in shoot induction
medium inhibited the regeneration in T. turcica explants. 83% of in vitro rooting was attained on pulsed-IBA treated shoots. The regenerated plants with well developed shoots and roots were successfully
acclimatized. Application of this study’s results has the potential to conserve T. turcica from extinction. 相似文献
2.
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
3.
When cotyledonary explants, excised from in vitro germinated seedlings, of pomegranate (Punica granatum L.) were incubated on solid Murashige and Skoog (1962) medium supplemented with 21 μM naptheleneacetic acid (NAA) and 9 μM 6-benzyladenine (BA), 80% of explants developed callus.
A high frequency of shoot organogensis was obtained when explants were incubated on MS medium supplemented with 8 μM BA, 6 μM
NAA, and 6 μM giberrellic acid (GA3). However, adding 24 μM silver nitrate (AgNO3) to this medium markedly enhanced shoot regeneration frequency (63%) and mean number of shoots per explant (11.26) and length
of shoots (2.22 cm). Highest frequency of in vitro rooting, mean number of roots/shoot (4.32), and mean root length (2.71 cm)
were obtained when regenerated shoots were transferred to half-strength MS medium supplemented with 0.02% activated charcoal.
Well-rooted plantlets were acclimatized, and then transferred to soil medium. Moreover, when zygotic embryos of P. granatum, excised from seeds collected at 16 weeks following full bloom, were incubated on MS medium containing 30 g l−1 sucrose, 15% coconut water, 21 μM NAA, and 9 μM BA, they developed the highest frequency of embryogenic callus, clumps with
globular embryos, and mean number of both globular and heart-shaped embryos per callus clump. Subjecting zygotic embryo explants
to six-week dark incubation period was essential for embryogenic callus induction, and these were subsequently transferred
to 16 h photoperiod for further growth and development of somatic embryos. Germination of somatic embryos was observed when
these were transferred to MS medium was supplemented with 60 g l−1 sucrose. 相似文献
4.
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
5.
An efficient and rapid method for in vitro clonal propagation of Huernia hystrix was developed, resulting in shoot regeneration within 3 weeks of culture. This endangered medicinal and ornamental succulent
is in high demand. Multiple shoots were regenerated from stem explants (10 mm length) cultured on Murashige and Skoog (MS)
medium containing 3% sucrose and supplemented with a range of NAA (0.00–8.06 μM) and BA (4.44–22.19 μM) concentrations. A
100% shoot response with a multiplication rate of four shoots per explant was obtained on MS medium containing 5.37 μM NAA
and 22.19 μM BA. Callus produced at the base of the explant on the same medium showed root organogenic potential. The in vitro
regenerated shoots produced roots when transferred to half strength MS medium with or without auxin. The micropropagated plants
were easily acclimatized within 2 months under greenhouse conditions when potted in a soil and sand mixture (1:1; v/v) treated
with a fungicide (Benlate, 0.01%). More than 95% survival with no observable morphological variations was obtained. The developed
protocol provides a simple, cost-effective means for the conservation of endangered H. hystrix by clonal propagation within a short time. 相似文献
6.
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
7.
Diwakar Aggarwal Anil Kumar M. Sudhakara Reddy 《Plant Cell, Tissue and Organ Culture》2010,102(1):45-52
An efficient shoot organogenesis system has been developed from mature plants of selected elite clones of Eucalyptus tereticornis Sm. Cultures were established using nodal explants taken from freshly coppice shoots cultured on Murashige and Skoog medium
containing 58 mM sucrose, 0.7% (w/v) agar (MS medium) and supplemented with 2.5 μM benzyladenine (BA) and 0.5 μM α-naphthaleneacetic
acid (NAA). Shoot organogenesis was achieved from leaf segments taken from elongated microshoots on MS medium supplemented
with 5.0 μM BA and 1.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The addition of cefotaxime to the medium promoted shoot
differentiation, whereas carbenicillin and cephalexin inhibited shoot differentiation. Maximum shoot bud organogenesis (44.6%)
occurred in explants cultured on MS medium supplemented with 5.0 μM BA, 1.0 μM 2,4-D and 500 mg/l cefotaxime. Leaf maturity
influenced shoot regeneration, with maximum shoot organogeneisis (40.5%) occurring when the source of explants was the fifth
leaf (14–16 days old) from the top of microshoot. Shoot organogenic potential also varied amongst the different clones of
E. tereticornis. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analyses indicated clonal uniformity of
the newly formed shoots/plants, and these were also found to be true-to-type. 相似文献
8.
Yohana de Oliveira Fernanda Pinto André Luís Lopes da Silva Ivan Guedes Luiz Antonio Biasi Marguerite Quoirin 《In vitro cellular & developmental biology. Plant》2010,46(2):192-197
Melaleuca alternifolia is cultivated for the production of an essential oil useful in the cosmetic and pharmaceutical industries. Despite the economic
importance of this species, there is little knowledge about its in vitro propagation. The aim of this study was to establish an efficient protocol for micropropagation of M. alternifolia. With the goal of in vitro multiplication by axillary shoot proliferation, both solid and liquid MS and WPM media were tested with supplementation with
BA at 0, 0.55, 1.11, 2.22, 3.33, and 4.44 μM. The best result for shoot multiplication was obtained when either 0.55 μM BA
was added into solid MS medium or 1.11 μM BA was added into liquid MS medium, with 5.6 and 11.8 shoots per explant generated,
respectively. On solid or liquid WPM medium supplemented with 0.55 μM BA, the proliferation rates were 5.5 and 4.7, respectively.
Three auxins (NAA, IAA, and IBA) were tested at 0.53 and 2.64 μM during the rooting stage. Several sucrose concentrations
(15, 30, and 45 g L−1) were compared to a sucrose-free medium. Rooting performances on four culture media were then compared: MS, half-strength
MS (MS/2), MS + activated charcoal (AC), and MS/2 + AC. The results showed that auxin addition to culture medium is not necessary
for in vitro rooting. Rooted microcuttings from different culture media were acclimatized in a greenhouse, and the survival percentage was evaluated.
All shoots cultured in an auxin-free MS medium supplemented with sucrose (30 g L−1) produced roots, and all plants survived during acclimatization. Activated charcoal added in rooting medium reduced rooting
rates. 相似文献
9.
B. Vinterhalter T. Janković K. Šavikin R. Nikolić D. Vinterhalter 《Plant Cell, Tissue and Organ Culture》2008,94(3):329-335
Shoot cultures of Gentianella austriaca (A. & J. Kerner) Dostal established from seedling epicotyls were maintained on MS medium supplemented with 2.22 μM BA and
0.54 μM NAA. A characteristic feature of these cultures was precocious flowering, which appeared in all rapidly elongating
shoots. Flower development arrested shoot elongation and multiplication of shoot cultures. Continuous shoot propagation was
possible only by use of small axillary or adventitious buds as explants for subculturing. Flowering could not be suppressed
by GA3 addition or by cultivation in short-day conditions. The highest rooting percentage (47.3% with 7.83 roots per explant) was
achieved on media with 4.92 μM IBA. Shoot cultures contained the same types of secondary metabolites as plants from nature.
Xanthones were the major constituents, with DMB (demethylbellidifolin), DGL (demethylbellidifolin-8-O-glucoside) and BGL (bellidifolin-8-O-glucoside) present at roughly two times lower concentrations than in samples from nature. Secondary metabolite production
was strongly affected by the presence of BA in the medium. 相似文献
10.
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
11.
An efficient, rapid and large scale propagation of a multipurpose herb, Ocimum basilicum through in vitro culture of nodal segments with axillary buds from mature plants has been accomplished. Among the cytokinins,
6-benzyladenine (BA), thidiazuron (TDZ), kinetin (Kin) and 2-isopentenyl adenine (2-iP) tested as supplements to Murashige
and Skoog (MS) medium, 5.0 μM BA was optimum in inducing bud break. The highest rate of shoot multiplication was achieved
on half-strength MS medium supplemented with 2.5 μM BA and 0.5 μM indole-3-acetic acid (IAA) combination. The shoots regenerated
from TDZ supplemented medium when subcultured to hormone-free MS medium considerably increased the rate of shoot multiplication
and shoot length by the end of third subculture. For rooting, MS medium supplemented with 1.0 μM indole-3-butyric acid (IBA)
proved to be better than that supplemented with IAA or α-naphthalene acetic acid (NAA). The in vitro raised plantlets with
well developed shoots and roots were successfully established in earthen pots containing garden soil and were grown in greenhouse
with 90% survival rate. Chlorophyll a and b, carotenoids and net photosynthetic rate were measured in leaves during ex vitro
acclimatization at 0, 7, 14, 21 and 28 days. Firstly these parameters showed a decreasing trend but subsequently increased
after 7 days of acclimatization. These findings indicate that the adaptation of micropropagated plants to ex vitro conditions
is more extended in time than generally accepted. 相似文献
12.
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
13.
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
14.
Giovanni Iapichino Marcello Airò 《In vitro cellular & developmental biology. Plant》2008,44(4):330-337
Multiple shoots were induced on stem segments of an 8-y-old plant of Metrosideros excelsa Sol ex Gaertn. “Parnel”. Axillary shoots produced on uncontaminated explants were excised, segmented, and recultured in the
same medium to increase the stock of shoot cultures. The Murashige and Skoog (MS) medium, augmented with different concentrations
of 2- isopenthenyladenine (2iP) and indole-3-acetic acid (IAA), either singly or in combinations, as potential medium for
shoot multiplication by nodal segments was tested. In the following experiment, equal molar concentrations of four cytokinins
[2iP, kinetin, zeatin, and N
6-benzyladenine (BA)] in combination with equal molar concentrations of three auxins [IAA, α-naphthaleneacetic acid (NAA),
and indole-3-butyric acid (IBA)] were tested for ability to induce axillary shoot development from single-node stem segments.
The highest rate of axillary shoot proliferation was induced on MS agar medium supplemented with 1.96μM 2iP and 1.14μM IAA
after 6 wk in culture. Different auxins (IAA, IBA, and NAA) were tested to determine the optimum conditions for in vitro rooting of microshoots. The best results were accomplished with IAA at 5.71μM (89% rooting) and with IBA at 2.85 or 5.71μM
(86% and 86% rooting, respectively). Seventy and 90 percent of the microshoots were rooted ex vitro in bottom-heated bench (22 ± 2°C) after 2 and 4 wk, respectively. In vitro and ex vitro rooted plantlets were successfully established in soil. 相似文献
15.
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
16.
Kaitlin J. Palla Paula M. Pijut 《In vitro cellular & developmental biology. Plant》2011,47(2):250-256
A plant regeneration protocol was developed for white ash (Fraxinus americana L.). Hypocotyls and cotyledons excised from embryos were cultured on Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine
(BA) plus thidiazuron (TDZ), and compared for organogenic potential. Sixty-six percent of hypocotyl segments and 10.4% of
cotyledon segments produced adventitious shoots, with a mean number of adventitious shoots per explant of 3.5 ± 0.9 and 2.5 ± 1.5,
respectively. The best regeneration medium (52% shoot formation; 47% shoot elongation) for hypocotyls was MS basal medium
containing 22.2 μM BA plus 0.5 μM TDZ, producing a mean of 3.9 ± 0.4 adventitious shoots. Adventitious shoots were established
as proliferating shoot cultures following transfer to MS medium with Gamborg B5 vitamins supplemented with 10 μM BA plus 10 μM
TDZ. For in vitro rooting, woody plant medium with indole-3-acetic acid (IAA) at 0, 2.9, 5.7, or 8.6 μM in combination with 4.9 μM indole-3-butyric
acid (IBA) was tested for a 5- or 10-d dark culture period, followed by culture under a 16-h photoperiod. The best rooting
(78% to 81%) of in vitro shoots was obtained with a 5 d dark culture treatment on medium containing 2.9 or 5.7 μM IAA plus 4.9 μM IBA, with an average
of 2.6 ± 0.4 roots per shoot. Rooted plants were successfully acclimatized to the greenhouse. This adventitious shoot regeneration
and rooting protocol will be used as the basis for experimental studies to produce transgenic white ash with resistance to
the emerald ash borer. 相似文献
17.
Summary This study reports a protocol for successful micropropagation of Decalepis arayalpathra (Joseph and Chandras) Venter. (Janakia arayalpathra Joseph and Chandrasekhran; Periplocaceae), a critically endangered and endemic ethnomedicinal plant in the southern forests of the Western Ghats which is overexploited
for its tuberous medicinal roots by the local Kani tribes. Natural regeneration is rare and conventional propagation is difficult.
Conservation of the species through micropropagation was attempted. The nodal explants of greenhouse-raised plants, were more
desirable than cotyledonary nodal explants of aseptic seedlings. The basal nodes (73%) of 12–16-wk-old greenhouse-grown plants
cultured in Murashige and Skoog (MS) medium containing 12.96 μM 6-benzyladenine (BA), 2.48 μM 2-isopentenyladenine (2-ip) and 2.68 μM α-naphthaleneacetic acid (NAA) formed 16–17 cm long unbranched robust solitary shoots in 8 wk. Cotyledonary nodal explants
cultured in the same medium showed multiple shoot formation and axillary branching. But the shoots were thin, fragile and
not suitable for mass propagation. Single nodes of a solitary shoot subcultured on MS medium containing 2.22 μM BA and 0.24 μM 2-ip together produced 9.8±0.3 nodes from 18.0±0.6 cm long shoots within 5–6 wk. The basal nodes of the shoots so formed
were repeatedly subcultured to increase the stock of propagules while the 2.5–3.0 cm terminal cuttings were used for rooting.
The best root induction (68%) and survival (86%) was achieved on half-strength MS medium supplemented with 1.07 μM NAA. Field-established plants showed uniform growth and phenotypic similarity to parental stock. 相似文献
18.
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
19.
Phillip A. Wadl Adam J. Dattilo Lisa M. Vito Robert N. Trigiano 《Plant Cell, Tissue and Organ Culture》2011,106(3):513-516
Pityopsis ruthii is an endangered herbaceous perennial species from the United States. In vitro multiplication of this species can be valuable
for germplasm conservation. Flower receptacles of P. ruthii were cultured on Murashige and Skoog medium (MS) supplemented with 11.4 μM indole-3-acetic acid (IAA) in combination with
2.2, 4.4 or 8.8 μM 6-benzyladenine (BA). Shoots were visible within 14–28 days and three plants were successfully rooted on
MS medium supplemented with 5.7 μM IAA. A two tailed t-test for paired-variates revealed that shoot regeneration on MS medium
amended with 11.4 μM IAA and 2.2 μM BA was significantly higher (P < 0.05) than on other treatments. Leaf explants were also cultured on MS not supplemented with growth regulators or supplemented
with 11.4 μM IAA in combination with 0, 2.2, 4.4 or 8.8 μM BA. Shoots were visible within 21–35 days and one plant was successfully
rooted on MS medium supplemented with 5.4 μM NAA. Shoot regeneration on MS medium augmented with 11.4 μM IAA and 2.2 μM BA
was significantly higher (P < 0.05) than the other treatments according to analysis of variance (ANOVA) with a rank transformation. Hyperhydricity and
rooting of shoots was problematic for explants derived from flower receptacles and leaf tissue, but viable plants were regenerated
using both explants sources indicating the potential role for micropropagation in the ex situ conservation of the species. 相似文献
20.
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