共查询到20条相似文献,搜索用时 31 毫秒
1.
Effects of growth regulators and incubation period on in vitro regeneration of adventitious shoots from gerbera petioles 总被引:4,自引:0,他引:4
Orlikowska Teresa Nowak Elzbieta Marasek Agnieszka Kucharska Danuta 《Plant Cell, Tissue and Organ Culture》1999,59(2):95-102
An effective system for in vitro regeneration of adventitious shoots from callus for the transformation or mutation of gerbera was developed. Callus was produced
from petioles of the youngest 3–4 leaves detached from auxillary shoots produced in vitro. Induction medium, on which leaves were incubated over 3 or 6 days, contained 2.3 μM thidiazuron and 0.53 μM α-naphthaleneacetic
acid. Explants were than transferred to one of three regeneration media with lower levels of growth regulators. Regeneration
was quantified over four (4-weeks each) passages at the time of explant transfer to fresh medium. Direct shoot regeneration
occurred during the first 4 weeks, and after these shoots were discarded a semi-compact organogenic callus was produced. Effectiveness
of shoot regeneration depended on four criteria: the cultivar (three cultivars were tested), the sequence of passage on regeneration
medium, the growth regulators in regeneration medium and the duration of the induction period. Regeneration potential from
calli of all cultivars increased from the first to the fourth passage. Duration of the incubation period on induction medium
(3 or 6 days) influenced regeneration to varying degrees, depending on the cultivar used and the regeneration medium contents.
There were no differences between two of the regeneration media – B, containing 2.2 μM 6-benzyladenine and 0.3 μM indole-3-acetic
acid and C, containing 4.4 μM 6-benzyladenine, 4.6 μM zeatin and 0.6 μM indole-3-acetic acid. Cultivar Mariola was the most
productive and regenerated more than seven shoots per callus in the fourth passage. Regeneration on medium B was further evaluated
on four additional gerbera cultivars.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
2.
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
3.
Pradeep K. Agarwal Rajinder S. Ranu 《In vitro cellular & developmental biology. Plant》2000,36(5):392-397
Summary The in vitro plant regeneration potential of vegetatively propagated geraniums (Pelargonium x hortorum) has been investigated. Using various combinations of growth regulators and a choice of different explants, a regeneration
protocol has been developed to raise in vitro plantlets from young petiole and leaf explants from three different cultivars of geraniums. In all three cultivars, very
young petiole explants exhibited a higher regeneration potential as compared with leaf explants. Regeneration efficiencies
were found to be highly dependent on the cultivar, with cv. Samba showing the highest regeneration potential, followed by
cvs. Yours Truly and then Sincerity. Samba also showed the highest number of shoots from both the petiole [57 shoot buds per
petiole explant in the presence of 3 μM zeatin and 1 μM indole-3-acetic acid (IAA) and leaf explants (43 shoots per leaf explant with 10 μM zeatin and 2 μM IAA). Shoot buds transferred to Murashige and Skoog (MS) medium supplemented with 0.44 μM N6-benzyladenine and 0.11 μM IAA grew vigorously and attained 1–2 cm in length in 3–4 wk. These shoots rooted with 100% efficiency on MS basal medium,
and plants developed that showed normal growth and flowering under greenhouse conditions. 相似文献
4.
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
5.
M. G. C. Costa F. T. S. Nogueira M. L. Figueira W. C. Otoni S. H. Brommonschenkel P. R. Cecon 《Plant cell reports》2000,19(3):327-332
Cotyledon explants of tomato (Lycopersicon esculentum Mill. cvs 'Santa Clara', 'Firme' mutant, 'IPA-5' and 'IPA-6') were excised from 8- to 10-day-old in vitro-grown seedlings.
Four different shoot induction media supplemented with timentin (300 mg l–1) were screened. When cotyledon explants were cultured on MS-based medium with 1.0 mg l–1 zeatin plus 0.1 mg l–1 IAA and supplemented with timentin, higher regeneration frequencies and a greater number of elongated shoots were obtained.
It was observed that timentin caused an increase in the morphogenesis of in vitro cotyledon explants of tomato cultivars.
In two of three cultivars tested, rooting of shoots was positively influenced, both in the presence and absence of timentin
in the rooting medium, among shoots regenerated from explants derived from timentin-supplemented medium. The results confirm
those of a previous investigation on the beneficial effects of this class of antibiotics on tomato regeneration and, consequently,
its reliability for use in the transformation of this species.
Received: 1 December 1998 / Revision received: 19 May 1999 · Accepted: 3 May 1999 相似文献
6.
K. Balaraju P. Agastian J. P. Preetamraj S. Arokiyaraj S. Ignacimuthu 《In vitro cellular & developmental biology. Plant》2008,44(5):436-441
This study describes in vitro shoot induction and plant regeneration from a mature apical meristem and nodal explants of the endangered medicinal shrub
Vitex agnus-castus. Multiple shoots were induced directly from the axis of nodal and apical meristem explants on Murashige and Skoog (MS) medium
containing 3% sucrose and different concentrations (1.0, 1.5, 2.0, and 2.5 mg/l) of 6-benzyl aminopurine (BAP) in combination
with Kinetin (Kin) and α-naphthalene acetic acid (NAA), both at 0.1 mg/l. BAP and Kinetin were used as supplements to MS basal
medium, either individually or in combination with auxins. The optimal concentration of BAP for inducing bud break was found
to be 2.0 mg/l when Kinetin was at 0.1 mg/l. Regeneration frequency was highest for both apical meristem and nodal explants
(94.5% and 90.3%, respectively) when explants were cultured on MS medium supplemented with BAP (2.0 mg/l) and Kin (0.1 mg/l).
A maximum of 7.7 ± 0.4 and 6.7 ± 0.2 shoots were obtained per explant for apical meristem and nodal explants, respectively.
Regenerated shoots, transferred to MS medium supplemented with either 1.0 or 1.5 mg/l BAP combined with 0.1 mg/l GA3, showed maximum elongation of 6.7 ± 0.4 and 6.0 ± 1.3 cm in apical meristem and nodal explants, respectively. In vitro regenerated shoots transferred to half-strength MS medium supplemented with 0.1 mg/l IBA induced 90.4% of the shoots to form
roots after 30–35 d of culture. Up to 80% of the regenerated shoots were successfully established in soil in the greenhouse. 相似文献
7.
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
8.
S. J. Murch K. L. Choffe J. M. R. Victor T. Y. Slimmon S. KrishnaRaj P. K. Saxena 《Plant cell reports》2000,19(6):576-581
St. John's wort (Hypericum perforatum. cv 'Anthos') is a medicinal plant with evidence of efficacy as an anti-depressant. The present report describes the development
of an in vitro regeneration system that utilizes thidiazuron [N-phenyl-N′-(1,2,3-thidiazol-yl)urea] for the induction of de novo shoots on etiolated hypocotyl segments of St. John's wort seedlings. The optimum level of thidiazuron supplementation to
the culture medium was 5 μmol·l–1 for a 9-day induction period followed by subculture of induced hypocotyl explants on basal medium. Other plant growth regulators
including benzyladenine and indoleacetic acid were not effective in inducing regeneration on St. John's wort hypocotyls. Histological
examination of the cultures revealed that the regenerated plants were derived from de novo developed shoots. Transfer of the regenerated shoots into a liquid medium with no plant growth regulators resulted in the
rapid and prolific growth of viable plantlets. The rapid and efficient micropropagation system for St. John's wort may be
useful for both the genetic improvement of this crop and the production of high-quality phytopharmaceutical preparations for
the treatment of neurological disorders.
Received: 19 March 1999 / Revision received: 5 July 1999 · Accepted: 17 August 1999 相似文献
9.
L. V. Hiregoudar H. N. Murthy J. G. Bhat A. Nayeem B. P. Hema E. J. Hahn K. Y. Paek 《Biologia Plantarum》2006,50(2):291-294
This report describes in vitro shoot induction and plant regeneration from mature nodal explants of Vitex trifolia L. on Murashige and Skoog (MS) medium fortified with benzylaminopurine (BAP), kinetin (KN), thidiazuron (TDZ), adenine (ADE),
and 2-isopentenyladenine (2-iP) (0.25 – 10.0 μM). Multiple shoots differentiated directly without callus mediation within
3 weeks when explants were cultured on medium supplemented with cytokinins. The maximum number of shoots (9 shoots per explant)
was developed on a medium supplemented with 5.0 μM BAP. Shoot cultures was established repeatedly subculturing the original
nodal explant on the same medium. Rooting of shoots was achieved on half strength MS medium supplemented with 0.5 μM naphthaleneacetic
acid (NAA). Rooted plantlets transferred to pots containing autoclaved soil and vermiculite mixture (1:1) showed 90 % survival
when transferred to outdoor. 相似文献
10.
S. R. Thengane D. K. Kulkarni V. A. Shrikhande K. V. Krishnamurthy 《In vitro cellular & developmental biology. Plant》2001,37(2):206-210
Summary Regeneration of adventitious shoots from the medicinal plant Nothapodytes foetida (Weight) Sleumer Syn. Mappia foetida (family Ieacinaceceae) has been achieved using different seedling explants. Direct, regeneration of shoot buds was observed
in Murashige and Skoog's (MS) basal medium supplemented with various concentrations of thidiazuron. The optimum levels of
thidiazuron concentrations were 0.91–4.45 μM. Leaf explants formed more shoots followed by hypocotyls or cotyledons. The shoot buds elongated and rooted on MS basal medium
with N6-benzyladenine (0.88–2.22 μM) and indole-3-butyric acid (0.49 μM). 相似文献
11.
Tatiana A. Vega Graciela M. Nestares Roxana Zorzoli Liliana Picardi 《Acta Physiologiae Plantarum》2006,28(5):427-431
Regeneration efficiency from three different regions of cotyledonary explants was examined in six sunflower inbred lines.
Proximal, middle and distal regions from seedling cotyledons were cultured on regeneration medium supplemented with growth
regulators. Plant regeneration by direct organogenesis was observed after four weeks. Significant differences among inbred
lines were found for regeneration percentage and average number of shoots per total explants. Also a decreasing regeneration
capacity was observed from proximal to distal sections for all inbred lines. Regeneration ability from cotyledonary explants
in this species is strongly influenced by the genotype and by the region from which the explant was obtained. The distance
to the cotyledonary node plays a preponderant role in the expression of shoot forming capacity. Shoot differentiation via seedling cotyledons depends upon the presence of the proximal region of cotyledon regardless of the genotype. 相似文献
12.
L. Venkatachalam R. Thimmaraju R. V. Sreedhar N. Bhagyalakshmi 《In vitro cellular & developmental biology. Plant》2006,42(3):262-269
Summary Direct shoot and cormlet regeneration from leaf explants were obtained in triploid dessert banana cultivar Nanjanagud Rasabale
(NR) that is classified under the group ‘Silk’ and has the genotype AAB. The response for both cormlet and direct shool formation
was observed only in leaf explants obtained from shoots cultured in liquid medium but not in similar explants obtained from
shoots grown on gelled medium. Shoot initiation occurred after a sequential culture of leaf (sheath) explants on modified
Murashige and Skoog (MS) medium supplemented with different growth regulators. In the sequence, the leaf explants were cultured
first on medium with a high level (22.4 μM) of benzyladenine (BA), second on indolc-3-butyric acid (IBA) supplemented medium, and third on reduced BA medium under incubation
in the dark. The highest adventitious shoot regeneration in 24% of the explants, with the number of shoots ranging from 2
to 3 per explant, occurred in the explants incubated at the first step in medium with 22.4 and 0.198 μM IBA. Further growth and complete shoot formation occurred under incubation in a 16-h photoperiod. While keeping the culture
conditions constant and replacing BA with picloram (0.83–20.71 μM) in the initial step, adventious origin of cormlets occurred in 12% of the explants. However, when rhizome explants (also
obtained from shoots grown in liquid medium) were cultured with various growth regulators in the first step, medium containing
2,4,5-trichlorophenoxyacctic acid (7.82 μM) produced friable callus that re-differentiated into roots only. Physical forms of the medium, ie.e. agar-gelled or liquid,
imparted specific effects on the extent of multiplication of leaf-regenerated shoots with no differences in morphology and
growth patterns when compared to those of meristem-derived plants. 相似文献
13.
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
14.
Greenhouse-grown plants of turnip rape Brassica rapa ssp. oleifera (syn. B. campestris) cv. Valtti and Sisu were transformed by Agrobacterium tumefaciens infection. Of the three A. tumefaciens strains tested (C58C1, EHA105 and LBA4404), LBA4404 gave the best results. Segments excised from one to two upper internodes
of an inflorescence-carrying stem served as explants for the Agrobacterium infection. Cultivation of the explants horizontally during the first 3 days of co-cultivation with A. tumefaciens following immediate selection of transformed tissue of the stem segments placed vertically basal side down were critical.
Use of silver nitrate (5–10 mg/l) in the culture medium and Micropore (3 M) paper tape for sealing plates was also beneficial.
Transgenic shoots were recovered using either hygromycin or kanamycin (20–25 mg/l) selection. Hygromycin was preferable, as
the proportion of `escapes' was 90% under kanamycin and 10% under hygromycin selection. Regeneration was achieved by culturing
the explants for 3–6 days on 0.5 mg/l of 2,4-di-chlorophenoxyacetic acid and 1–2 weeks on 2–3 mg/l of 6-benzyl aminopurine
with/without 0.05 mg/l α-naphthaleneacetic acid. Recovered shoots were then cultured on hormone-free MS medium. This culture program gave 60–80% shoot
regeneration. Regenerants were tested by histological β-glucuronidase staining and Southern blotting. The recovery rate of transgenic shoots was 4–9% of the number of explants used
in the experiments.
Received: 28 November 1997 / Revision received: 25 March 1998 / Accepted: 22 November 1998 相似文献
15.
Summary A viable protocol has been developed for direct and indirect shoot regeneration of Vernonia cinerea. To establish a stable and high-frequency plant regeneration system, leaf and stem explants were tested with different combinations
of α-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), and benzylaminopurine (BA). Lateral buds on nodal explants
grew into shoots within 2 wk of culture in Murashige and Skoog (MS) basal medium supplemented with 20.9 μM BA. Excision and culture of nodal segments from in vitro-raised shoots on fresh medium with the same concentration of BA facilitated development of more than 15 shoots per node.
Similarly leaf, nodal, and internodal explants were cultured on MS basal medium supplemented with different concentrations
of BA, NAA, and IAA either alone or in combinations for callus induction and organogenesis. Shoot buds and/or roots were regenerated
on callus. Shoot buds formed multiple shoots within 4 wk after incubation in induction medium. Adventitious buds and shoots
proliferated when callus was cut into pieces and subcultured on MS basal medium containing 20.9 μM BA and 5.3 μM NAA. This combination proved to be the best medium for enhanced adventitious shoot bud multiplication, generating a maximum
of 50 shoots in 4 wk. This medium was also used successfully for shoot proliferation in liquid medium. Root formation was
observed from callus induced in medium containing 8.05–13.4 μM NAA. Regenerated shoots exhibited flowering and root formation in MS basal medium without any growth regulators. Plantlets
established in the field showed 85% survival and exhibited identical morphological characteristics as the donor plant. 相似文献
16.
G. H. Ma C. X. He H. Ren Q. M. Zhang S. J. Li X. H. Zhang B. Eric 《Biologia Plantarum》2010,54(2):361-365
An efficient propagation system via somatic embryogenesis and shoot organogenesis and plant regeneration system for endangered species Primulina tabacum Hance was established. Thidiazuron (TDZ) was the key plant growth regulator for inducing somatic embryogenesis and kinetin
(KIN) and 6-benzylaminopurine (BAP) were the key cytokinins for inducing shoot organogenesis from leaf explants. TDZ combined
with BAP or KIN in the induction Murashige and Skoog medium induced both somatic embryos and adventitious shoots. Leaf explants
with abaxial site in contact with the medium induced less somatic embryos or adventitious shoots compared to inversely placed
leaf explants and the optimum pH was 6.5–7.0. Secondary somatic embryos or adventitious shoot could be induced from primary
somatic embryos using TDZ and BAP. Shoots developed adventitious roots on rooting medium containing 0.5 μM indole-3-butyric
acid and 0.2 % activated carbon. Over 90 % of plantlets survived following acclimatization and transfer to potting mixture
(sand:Vermiculite:limestone; 1:2:1). 相似文献
17.
Callus was produced on cotyledon, shoot tip, hypocotyl and root explants of twoCorchorus species on several media. Cytokinin was necessary for callus production on cotyledon explants. BothC.olitorius genotypes produced most callus on media with zeatin and either NAA or IAA, and theC.capsularis genotype produced most callus on media with IAA and either zeatin or BA. High frequencies of regenerated shoots were obtained
from shoot tip explants of both species, from the apical meristem and from callus. Media with 2.0 mg 1−1 BA were superior for both species, and media with zeatin were equally good forC.capsularis only. More regeneration was obtained for all genotypes after subculture of callus on media with 2.0 mg 1−1 zeatin. Cotyledon callus produced less regeneration, also with differences between genotypes; explants of both genotypes
ofC.olitorius produced regeneration on a medium with NAA and zeatin, and theC.capsularis genotype produced regeneration on a medium with IAA and BA. Limited regeneration from root explant callus was obtained forC.capsularis only on medium with BA and IAA. Regeneration was not obtained from hypocotyl callus. Further regeneration of shoots of both
species was obtained from secondary callus after subculture, and from nodal segments of regenerated shoots and of seedling
shoots cultured on basic MS medium without growth hormones. Roots were produced on about 80% of all shoots after transference
to medium with 0.2 mg 1−1 IBA, and rooted plantlets survived and flowered normally after transference to compost. 相似文献
18.
Gerard C. Douglas John Mcnamara 《In vitro cellular & developmental biology. Plant》2000,36(5):412-415
Summary Regeneration of adventitious shoots was obtained in over 80% of explants, consisting of wounded cotyledonary nodes of Acacia mangium, by culturing germinated seedlings on DKW medium with combinations of N6-benzyladenine and either thidiazuron or N-(2-chloro-4-pyridyl)-N-phenylurea. Electron microscopy showed the presence of adventitious buds arising from wound tissue of the cotyledons and
cotyledonary nodes. Shoot regeneration was also obtained at lower frequency in isolated cotyledon explants cultured with 6%
sucrose alone (10%), or with 3% sucrose and 30.0 mg l−1 (0.1 μM) 2–4-dichlorophenoxyacetic acid (2,4-D; 16%). With 2,4-D,>60% of explants produced organized structures but these did not
develop into shoots or somatic embryos. Shoot formation was not induced in either hypocotyl or root explants. 相似文献
19.
Asma Ben Ghnaya Gilbert Charles Michel Branchard 《Plant Cell, Tissue and Organ Culture》2008,92(1):25-30
The present work describes a procedure that allows for the easy and rapid induction of caulogenesis in four cultivars of Brassica napus L. from transversal Thin Cell Layers (tTCLs). In order to investigate the regeneration ability of this crop, the effects
of genotype, explant source and culture medium were examined on shoot regeneration. The tTCL explants were excised from hypocotyl
and petiole of 2-week-old seedlings and cultured on a solid basal MS medium supplemented with α-naphthaleneacetic acid (NAA:
0.1–0.4 mg l−1), 6-benzylamino-purine (BAP: 1–4 mg l−1) and sucrose (20–40 g l−1). A significant genotypic effect was observed between the four cvs; Jumbo and Drakkar displayed higher capacities to produce
shoots than Pactol and Cossair. Regeneration commenced earlier and the percentage of shoot-producing explants as well as the
number of shoots per regenerating explant was greater. The comparison between the regeneration ability of different explants
showed that the hypocotyls exhibited a high rate of shoot organogenesis when they were cultured on MS medium supplemented
with 3 mg l−1 BAP, 0.3 mg l−1 NAA and 30 g l−1 sucrose. Adventitious shoot buds developed from 46% of the tTCLs, with a mean of 7.5 buds. Furthermore, the method was fast
with shoot formation occurring by 7 days culture. Plantlets regenerated from all shoots and developed normally. The regenerated
plants were fertile and identical to source plants. 相似文献
20.
Callus induction and in vitro plantlet regeneration systems for safflower (Carthamus tinctorius L.) cv. Bhima using root,
hypocotyl, cotyledon and leaf explants were optimized by studying the influence on organogenesis of seedling age, media factors,
growth regulators and excision orientation. Supplementation of the medium with an auxin: cytokinin ratio < 1 enhanced the
growth rate of callus cultures; however, for 2,4-D the ratio was > 1.34–11.41 μM concentrations of growth regulators (IAA,
NAA, BA and Kinetin) in the medium were found effective for callus induction and regeneration in all explants. The calli could
be maintained over 32 months. BA (4.43 μM) combined with casein hydrolysate (10 mg l-1) yielded the highest rate of shoot
production on hypocotyl (3–6) and cotyledon (5–7) explants and cotyledonary derived callus (4–8). More shoots were produced
on explants cut from the most basal region of cotyledons from 5 to 7-day-old seedlings than from older seedlings or more distal
cut sites. Apolar placement of explants, inhibited shoot regeneration. The shoot regeneration potential remained upto 7 months
in calli developed on NAA + BA. Of three media tested, MS was superior to SH-M and B5. Rooting of shoots was not efficient;
42% of the shoots were rooted on MS medium containing sucrose (7–8%) + IAA (2.8–5.7 μM). Capitula induction was observed in
both callus mediated shoots on cotyledons and shoots on rooting medium with sucrose, IAA, NAA and IBA. Well developed plantlets
were transferred to the field with a 34% success rate.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献