共查询到20条相似文献,搜索用时 828 毫秒
1.
Efficient plant regeneration through somatic embryogenesis was achieved from callus cultures derived from semi-mature cotyledon explants of Dalbergia sissoo Roxb., a timber-yielding leguminous tree. Somatic embryos developed over the surface of embryogenic callus and occasionally, directly from cotyledon explants without intervening callus phase. Callus cultures were initiated from cotyledon pieces of D. sissoo on Murashige and Skoog (1962) medium supplemented with 4.52, 9.04, 13.57, and 18.09 mumol/L 2,4-dichlorophenoxyacetic acid and 0.46 mumol/L Kinetin. Maximum percentage response for callus formation was 89% on MS medium supplemented with 9.04 mumol/L 2,4-D' and 0.46 mumol/L Kn. Somatic embryogenesis was achieved after transfer of embryogenic callus clumps to 1/2-MS medium without plant growth regulators (1/2-MSO). Average numbers of somatic embryos per callus clump was 26.5 on 1/2-MSO medium after 15 weeks of culture. Addition of 0.68 mmol/L L-glutamine to 1/2-MSO medium enhanced somatic embryogenesis frequency from 55% to 66% and the number of somatic embryos per callus clump from 26.5 to 31.1. Histological studies were carried out to observe various developmental stages of somatic embryos. About 50% of somatic embryos converted into plantlets on 1/2-MSO medium containing 2% sucrose, after 20 days of culture. Transfer of somatic embryos to 1/29-MSO medium containing 10% sucrose for 15 days prior to transfer on 1/2-MS medium with 2% sucrose enhanced the conversion of somatic embryos into plantlets from 50 to 75%. The plantlets with shoots and roots were transferred to 1/2 and 1/4-liquid MS medium, each for 10 days, and then to plastic pots containing autoclaved peat moss and compost mixture (1:1). 70% of the plantiets survived after 10 weeks of transfer to pots. 120 regenerated plantlets out of 150 were successfully acclimatised. After successful acclimatisation, plants were transferred to earthen pots. 相似文献
2.
Plantlets were regenerated from cultured seed explants of the forage grass Caucasian bluestem [Bothriochloa caucasica (Trin.) C.E. Hubbard] via somatic embryogenesis. Embryogenic callus was produced in four weeks when surface sterilized seeds were cultured on a medium containing MS-salts, B-5 vitamins, 12 mM L-proline, 2% sucrose, 0.8% agar and 5M 2,4-D. Plantlets were regenerated in 6–8 weeks after culture initiation. Healthy root and shoot systems were produced within three weeks after the plantlets were transferred to a medium lacking 2,4-D. Approximately 95% of the plantlets survived greenhouse acclimation and produced healthy plants and viable seeds. Caucasian bluestem callus cultures exhibit natural resistance to kanamycin. High levels of kanamycin (up to 800 mg/l) did not completely inhibit callus growth. However, the regeneration of healthy-plantlets was completely inhibited by kanamycin even at low levels (50 mg/l). 相似文献
3.
C. Pugliesi M. Rabaglio F. Cecconi S. Baroncelli 《Plant Cell, Tissue and Organ Culture》1992,28(2):125-128
Different plant explants of Persian buttercup (Ranunculus asiaticus L.) were screened for callus induction and adventitious shoot regeneration on different media to establish totipotent cultures. Murashige & Skoog (MS) medium was used, supplemented with different concentrations of the following growth regulators: kinetin, benzyladenine (BA), naphthaleneacetic acid (NAA) and indoleacetic acid (IAA). Callus was induced and adventitious buds regenerated only from cotyledonary explants after 4–5 weeks. Subculture of the regenerated buds on the same basal medium in presence of gibberellic acid (GA3) and BA produced well-organized shoots. Rooting was obtained by transferring shoots to growth regulator-free MS medium. A high rate of shoot multiplication has been achieved on medium with high concentration of kinetin and long-day photoperiod. Finally the plants were successfully transferred to soil and grown in a greenhouse. 相似文献
4.
An efficient method for the in vitro propagation of a tea (Camellia sinensis (L) O. Kuntze) clone, `TRI-2025', from somatic embryos is described. This technique involves two phases; the induction of
adventitious buds from nodal cuttings followed by the development of somatic embryos. Single nodal cuttings were excised from
1-year-old in vitro axenic cultures and inoculated on MS medium with different combinations of IBA/BAP/GA3. Induction of multiple shoots from nodal explants occurred on MS medium with 0.5 mg l–1 BAP, 0.1 mg l–1 IBA and 0.0 mg l–1 GA3 within 6 weeks of incubation. The cultures with multiple shoots were transferred to fresh medium, incubated for 120 days
and transferred to MS medium with half-strength macro nutrients, full-strength micronutrients and vitamins and no growth regulator.
The direct induction of somatic embryos without callus formation occurred on this medium at 60% frequency within 4 weeks.
The production of embryos continued upon transfer of the cultures to fresh medium and a four- to eightfold multiplication
rate was obtained during each 6-week culture cycle. The plantlets from these embryos were acclimatised with a 90% success
rate. All plants were vigorous and hardy, with well-developed tap-root systems.
Received: 20 July 1996 / Revision received: 2 January 1998 / Accepted: 19 January 1998 相似文献
5.
Callus cultures were established from the scutellum, scutellar node and radicle region of immature embryos of rye and octoploid
triticale on modified Murashige-Skoog basal medium supplemented with various growth regulators. 2, 4-D, 2, 4, 5-T and 2, 4,
5-Cl, POP were found suitable for initiation and maintenance of callus cultures. Cytokinins had no or inhibitory effect on
callus induction and growth. On basal medium containing 5 mg/l of 2,4,5-Cl3 POP, 16% of triticale and 17% of rye primary cultures exhibited shoot bud regeneration after 3–4 weeks. Transfer of such
cultures to basal medium supplemented with zeatin or zeatin in combination with IAA further promoted shoot elongation and
plantlet formation. Plantlets were rooted on basal medium containing 1 mg/l NAA and were eventually transferred to soil. Chlorophyll
variants were observed in about 6% of triticale cultures. 相似文献
6.
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
7.
Konstantin V. Kiselev Anna V. Turlenko Yuri N. Zhuravlev 《Plant Cell, Tissue and Organ Culture》2009,99(2):141-149
A somatic embryogenesis protocol for plant regeneration of northern red oak (Quercus rubra) was established from immature cotyledon explants. Embryogenic callus cultures were induced on Murashige and Skoog medium
(MS) containing 3% sucrose, 0.24% Phytagel™, and various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-d) after 4 weeks of culture in darkness. A higher response (66%) of embryogenic callus was induced on 0.45 μM 2,4-d. Higher numbers of globular- (31), heart- (17), torpedo- (12), and cotyledon-stage (8) embryos per explant were obtained
by culturing embryogenic callus on MS with 3% sucrose, 0.24% Phytagel™, and devoid of growth regulators after 8 weeks culture
in darkness. Continuous sub-culturing of embryogenic callus on medium containing 2,4-d yielded only compact callus. Desiccation of embryos for 3 days in darkness at 25 ± 2°C followed by cold storage at 4°C in
darkness for 8 weeks favored embryo germination and development of plantlets. Cotyledon-stage embryos subjected to desiccation
and chilling treatment cultured on MS with 3% sucrose, 0.24 Phytagel™, 0.44 μM 6-benzylaminopurine (BA), and 0.29 μM gibberellic
acid germinated at a higher frequency (61%) than with 0.44 μM BA alone and control cultures. Germinated plantlets developed
a shoot and root, were acclimatized successfully, and maintained in a growth room for plantlet development. 相似文献
8.
A highly reproducible system for efficient plant regeneration from protoplast via somatic embryogenesis was developed in cotton (Gossypium hirsutum L.) cultivar ZDM-3. Embryogenic callus, somatic embryos and suspension culture cells were used as explants. Callus-forming
frequency (82.86 %) was obtained in protoplast cultures from suspension culture cells in KM8P medium with 0.45 μM 2,4-dichlorophenoxyacetic acid (2,4-D), 0.93 μM kinetin (KIN), 1.5 % glucose and 1.5 % maltose. Protocolonies
formed in two months with plating efficiency of 14 %. However, the callus-forming efficiencies from other two explants were
low. The calli from protoplast culture were transferred to somatic embryo induction medium and 12.7 % of normal plantlets
were obtained on medium contained 3 % maltose or 1 % of each sucrose + maltose + glucose, 2.46 μM indole-3-butyric acid (IBA)
and 0.93 μM KIN. Over 100 plantlets were obtained from protoplasts derived from three explants. The regenerated plants were
transferred to the soil and the highest survival rate (95 %) was observed in transplanting via a new method. 相似文献
9.
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
10.
M. Barghchi 《Plant Cell, Tissue and Organ Culture》1988,15(3):233-244
Procedures were developed for micropropagation of Alnus cordata through in vitro axillary shoot multiplication of axillary bud explants cultured in Murashige & Skoog (MS) medium. Establishment of cultures from plants grown in the field was very difficult due to bacterial contamination and phenolic oxidation in explants causing severe browning. Explants were first cultured on an MS medium containing 4.4 M 6-benzyladenine and 87.6 mM sucrose (initiation medium) for 7 days and then transferred to an MS medium containing 1.1 M 6-benzyladenine and 333 mM glucose (multiplication medium) for a further 20–25 days. It was necessary to transfer cultures from initiation medium to multiplication medium after 7 days to minimize excessive callus growth, abnormally thick and brittle leaves, inhibition of shoot elongation, and senescence. Shoot multiplication comparable to the above method was achieved by culture of axillary bud explants in MS medium supplemented with 1.1–4.4 M 6-benzyladenine and 333 mM glucose 4–5 weeks after culture. Shoots rooted in MS medium (1/2 x macro-nutrients) supplemented with 1.2–4.9 M indolebutyric acid. Also, 98% rooting was achieved when cultures were treated with 625 mgl-1 indolebutyric acid for 24 h at the end of the shoot production stage and rooted in vivo as mini-cuttings. Plantlets established well in soil. 相似文献
11.
M. C. San-José E. Corredoira M. T. Martínez N. Vidal S. Valladares R. Mallón A. M. Vieitez 《Plant cell reports》2010,29(6):661-671
A procedure for inducing somatic embryos in shoot apex explants (2 mm) excised from shoot proliferation cultures established
from adult oak trees (Quercus robur) was investigated. Embryogenesis was induced in shoot tip as well as leaf explants in three out of the five genotypes evaluated.
Somatic embryos were formed by culture in induction medium supplemented with 21.48 μM naphthalene acetic acid and 2.22 μM
benzyladenine for 8 weeks, and successive transfer of explants to expression media with a low concentration of growth regulators
and without them. Both types of explants formed callus tissue from which somatic embryos developed, indicating indirect embryogenesis.
Although the embryogenic frequencies were lower than 12%, it did not prevent the establishment of clonal embryogenic lines
maintained by repetitive embryogenesis. Histological study confirmed an indirect somatic embryogenesis process from shoot
tip explants, in which leaf primordia and the corresponding axial zones were involved in generating callus, whereas the apical
meristem itself did not proliferate. The origin of embryogenic cells appeared to be associated with dedifferentiation of certain
parenchymal cells in callus regions after transfer of explants to expression media without auxin. Division of embryogenic
cells gave rise to proembryo aggregates of unicellular origin, although a multicellular origin from bulging embryogenic areas
would also seem possible. Further development led to the formation of cotyledonary-stage somatic embryos and nodular embryogenic
structures that may be considered as anomalous embryos with no clear bipolarity. Inducement of somatic embryos from explants
isolated from shoot cultures ensures plant material all year round, thus providing a significant advantage over the use of
leaf explants from field-grown trees. 相似文献
12.
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
13.
Cotyledon explants of Panax ginseng produced somatic embryos directly on solid hormone-free MS medium containing 3% (w/v) sucrose while high concentration of NH4NO3 (60 mM) induced embryogenic callus. Ten subcultures of the embryogenic callus on hormone-free MS medium with 40 mM NH4NO3 gave hormone-independent proliferation of callus, which exhibited proliferation potential even on MS medium with a standard level of NH4NO3 (20 mM). Pulse treatment of callus with exogenous auxin or cytokinin (1.0 mg 1–1 2,4-D, 1.0 mg 1–1 kinetin) resulted in the loss of the hormone-independent characteristic and caused the callus to brown. For the suspension culture, embryogenic callus was transferred to MS liquid medium containing 3% (w/v) sucrose in an 500 ml Erlenmyer flask. Embryogenic cell clumps in full-strength MS liquid medium discharged toxic substances, resulting in strong suppression of cell growth. In 1/3-strength MS medium, exudation of toxic material did not occur. Embryogenic cell clumps were mass-grown on a large-scale in a bioreactor (20-1), showing a 7.1 increase of fresh weight in 1/3-strength MS medium with 3% (w/ v) sucrose after 5 weeks of culture. Total ginsenoside content of cultured embryogenic cell clumps was low and 6 times below naturally-cultivated ginseng roots. 相似文献
14.
Q. C. Liu H. Zhai Y. Wang D. P. Zhang 《In vitro cellular & developmental biology. Plant》2001,37(5):564-567
Summary Using 15 Chinese and Japanese cultivars of sweetpotato, Ipomoea batatas (L.) Lam., we succeeded in developing an efficient plant regeneration system from embryogenic suspension cultures. The embryogenic
callus derived from shoot apices of the 15 cultivars was used to initiate embryogenic suspension cultures in Murashige and
Skoog (MS) medium containing 9.05 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Rapidly proliferating and well-dispersed embryogenic suspension cultures were established.
Cell aggregates 0.7–1.1 mm in size from embryogenic suspension cultures were transferred to solid MS medium supplemented with
9.05 μM of 2,4-D and formed embryogenic callus with somatic embryos. The embryogenic callus with somatic embryos was further transferred
to MS medium supplemented with 3.78 μM of abscisic acid, resulting in the germination of somatic embryos. Within 20 wk after the initiation, the frequencies of
cell aggregates forming plantlets reached approximately 100% for the 15 tested cultivars. These plantlets, when transferred
to soil, showed 100% survival. No morphological variations were observed. 相似文献
15.
Regeneration from Phylloclade Explants and Callus Cultures of Schlumbergera and Rhipsalidopsis 总被引:1,自引:0,他引:1
Phylloclade explants of Schlumbergera and Rhipsalidopsis were cultured in vitro to produce axillary and adventitious shoots. The explants of both species, taken from greenhouse-grown plants, produced only
axillary shoots. There was a pronounced improvement in adventitious shoot formation in phylloclade explants of cultivar CB4
of Rhipsalidopsis by increasing numbers of subcultures of axillary shoots used as donor plants. The axillary shoots generated from the explants
were either subcultured to produce successive generations of axillary shoot cultures or made into phylloclade explants and
tested for adventitious shoot formation at each subculture. The duration of each subculture varied from 6 to 12 weeks. After
the first subculture, sporadic adventitious shoot formation began, and after the third subculture 87% explants of cultivar
CB4 produced adventitious shoots at a frequency of about 12 shoots per explant. In contrast, there was no improvement in regenerative
ability in explants of cultivar Thor-Olga of Schlumbergera up to third subculture. Adventitious shoots could be produced by callus culture too. Cultivar CB4 was highly regenerative,
producing as many as 10 adventitious shoots per square cm of callus. In vitro grown plantlets, when transferred to pots continued to show prolific growth. 相似文献
16.
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
17.
Several plant growth regulators BA, TDZ, 2,4- and Kn were tested alone or in combination for their capacity to induce indirect somatic embryogenesis from leaf and internode explants of Paulownia elongata. Calli were produced when leaf explants were cultured on Murashige and Skoog (MS) medium containing 3 % sucrose, 0.4 % phytagel, 4 mg l-1 TDZ and 0.1 mg l-1 Kn after 3 weeks and the initiation rate was 54.1%. After subculturing on the same medium, embryos at various developmental stages (globular, heart and torpedo shaped) were transferred for maturation onto MS medium supplemented with 3 % sucrose, 0.4 % phytagel, 0.1 mg l-1 TDZ, 1 mg l-1 Kn and 2 mM glutamine. An average of 50.7 somatic embryos were obtained from 100 mg of embryogenic callus after 4 weeks at high frequency (64.7 %). Afterward, mature somatic embryos were isolated and cultured on hormone-free MS medium for germination (80 %) and development into plantlets. Plantlets were transferred to pots with a mixture of peat and perlite in a 3:1 ratio and showed a survival rate of 70–80 %. Plantlets regenerated by this procedure were morphologically identical to the donor material and developed normally in the greenhouse. 相似文献
18.
D. H. Tejavathi M. D. Rajanna R. Sowmya K. Gayathramma 《In vitro cellular & developmental biology. Plant》2007,43(5):423-428
Somatic embryogenesis from cultures of shoot apices, cotyledon and young leaves of in vitro shoots of Agave vera-cruz Mill. was studied. Embryogenic callus was obtained when explants were cultured on Murashige and Skoog’s (MS) medium (1962)
supplemented with L2 vitamins, 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-d) or 5.37 μM ∝-naphthalene acetic acid (NAA). Somatic embryos differentiated from this embryogenic callus upon subculture
to maturation/conversion medium containing cytokinin either alone or with auxin and l-glutamine. The best combination of growth regulators for development of somatic embryos was found to be 5.37 μM naphthalene
acetic acid plus 0.91 μM zeatin and 40 g/l sucrose. The conversion frequency of somatic embryos to plantlets varied from 46–50%.
Rooted plantlets were transferred directly to pots containing a soil, sand, and manure mixture without any hardening phase
with 96–98% survival of the plantlets. Based on the histological observations, the potential origin of the somatic embryo
is discussed. 相似文献
19.
Mistianne Feeney Basdeo Bhagwat Jeremy S. Mitchell W. David Lane 《Plant Cell, Tissue and Organ Culture》2007,90(2):201-214
A complete method to regenerate adventitious shoots and to produce field-ready trees from three commercial cultivars of sweet
cherry (Prunus avium L.) is described. The effects of explant types, pre-treatments, basal media, and phloroglucinol on cultivars Bing, Sweetheart,
and Lapins were investigated. Callus developed on four explant types: apical shoot tips isolated from orchard trees; and punctured
shoot tips, stem sections, and shoot bases of in vitro shoot cultures. Callus formed on Bing (5%), Sweetheart (8%), and Lapins
(20%) shoot tips from orchard trees after 4 months on Murashige and Skoog medium (MS) at half-strength with 3 μM benzylaminopurine
(BA). In vitro-derived explants formed callus after 3 months on Woody Plant Medium with 3 μM BA (W3B): punctured shoot tips
(Sweetheart and Lapins 67%), stem sections (Sweetheart 31%, Lapins 27%), and shoot bases (Sweetheart 10%, Lapins 17%). Pre-treatment
of shoot cultures on MS with 3 μM BA and 1 mM phloroglucinol increased callus formation three-fold on shoot base explants.
Callus was separated from parental explants and maintained on MS with 3 μM BA. Shooting was induced by transferring callus
to W3B. At 2 weeks, shoot development approached 100%. By 4 weeks, 7–17 shoots had formed on each explant. Callus was maintained
for 1.5 years with no decrease in shoot production. Shoots were grafted onto Mazzard (P. avium) rootstocks with 54% (Sweetheart), 57% (Lapins), and 21% (Bing) success after 5 weeks. 相似文献
20.
Nodal sections of Clematis integrifolia × C. viticellawere cultured at 24 °C in darkness on a medium containing the salts and vitamins of Murashige and Skoog (1962) supplemented
with sucrose (30 g l−1), 2 μM 6-benzylaminopurine (BAP) and 0.5 μM 4-indole-3-yl-butyric acid (IBA). These explants produced a white friable callus
on their surfaces. Somatic embryos were first observed on the surface of the callus after eighteen months in culture. Thereafter,
pieces (125 mm3) of the embryogenic mass were subcultured every 4 weeks and continued to produce somatic embryos over the two-year period
of observation. A mean (± SE) of 64±4 cotyledonary stage embryos were observed per 125 mm3 callus four weeks after transfer to fresh medium. Comparison of the effect of growth regulators on conversion showed that
the highest frequency of unipolar and bipolar conversions occurred on medium containing 10 μM kinetin and 1 μM BAP. Shoots
were excised from embryos and inserted in Sorbarods saturated with liquid medium containing 0.05 μM IBA and 0.05 μM 1-naphthalenacetic
acid. After four weeks 88% had formed root and survived transfer to compost in a greenhouse.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献