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1.
Summary In order to establish a protocol for somatic embryogenesis of annatto, Bixa orellana L., seeds (70 d after anthesis) from field-grown orchards had their coats dissected off, and immature zygotic embryos were
excised aseptically from immature seeds collected from field-grown trees and used as explants. Embryos were cultured onto
MS medium supplemented with or without different combinations of plant growth regulators and activated charcoal. Direct somatic
embryogenesis was induced on explants incubated either in Murashige and Skoog (MS), 2,4-dichlorophenoxyacetic acid (2,4-D),
and/or kinetin-supplemented media after 25 d of culture. The highest frequencies of embryogenesis and embryos per explant
were obtained on medium containing 2.26 μM 2.4-D, 4.52μM kinetin, and 1.0 gl−1 activated charcoal. The presence of charcoal was critical in increasing embryos per explant, to reduce the time to obtain
somatic embryos, and mainly to prevent callus proliferation and subsequent indirect somatic embryogenesis. No embryogenic
response was achieved when mature embryos were used. It was also observed that embryogenic response was significantly affected
by genotype. Histological investigations revealed that primary direct somatic embryos differentiated exclusively from the
protodermis or together with the outer ground meristem cell layers of the zygotic embryo axis, and from the protodermis of
zygotic cotyledons. Diverse morphological differences, including malformed embryos, were observed among somatic embryos. In
spite of the high frequencies of histodifferentiation of all embryo stages, a very low conversion frequency to normal plants
from somatic embryos was observed. 相似文献
2.
Ajith Anand Chaluvadi Srinivasa Rao 《In vitro cellular & developmental biology. Plant》2000,36(1):61-64
Summary A protocol is described for rapid multiplication of Piper barberi Gamble (Piperaceae) through shoot tip and nodal explant cultures. Nodal explants with a single axillary meristem showed three
times better response with respect to shoot proliferation when compared to shoot tip explants. The best shoot proliferation
response of nodal explants was observed with a cytokinin combination of N6-benzyladenine (4.43 μM) and kinetin (2.32 μM), with 88% bud break. The number of shoot initials (2.4) produced per nodal explant was twice the number of shoot initials
(1.2) per shoot tip. An average of 6.9±0.58 adventitious shoots were observed from the proximal end of the internodal explants
on Mursashige and Skoog (1962) (Ms) basal medium supplemented with N6-benzyladenine (2.22 μM) and kinetin (0.46 μM). A multiplication rate of 82 shoots per explant could be achieved after 9 wk of subculturing. The in vitro shoots were rooted on one-half and one-quarter MS basal medium. The shoots rooted on one-quarter MS in the dark produced
eight roots with an average root length of 3.36 cm and 98% survival. These plants were transferred to the field with a survival
rate of 75%. 相似文献
3.
Summary Somatic embryo (bipolar) or shoot (monopolar) morphogenesis in mesophyll cells of Euphorbia nivulia Buch.-Ham in vitro was dependent on the type of auxin supplementing Murashige and Skoog (MS) medium containing benzyladenine. Direct in vitro morphogenesis, i.e., organogenesis, and somatic embryogenesis were significantly influenced by seasonal growth of the donor
plant, explant position (proximal, mid, and distal), and light. Explants collected in march/April were superior to July/August
material. Proximal explants underwent morphogenesis more readily than mid- and tip-derived explants. Incubation in the light
favored morphogenesis while darkness was inhibitory. Kinetin (Kn) was also inhibitory to morphogenesis. MS medium enriched
with different levels of N6-benzyladenine (BA) alone, or in combination with α-naphthaleneacetic acid (NAA) or indole-3-acetic acid (IAA), induced adventitious
shoots directly. Explants collected in March/April cultured on medium with 13.3 μM BA and 2.69 μM NAA developed the highest number of shoots, a mean of 15.2 shoots per proximal explant. Developed shoots rooted the best
on half-strength MS medium with 2.46 μM indole-3-butyric acid, which developed a mean of 5.2 roots per shoot. Rooted healthy shoots could be transplanted to small
pots, with an 80% survival rate. Addition of 2,4-dichlorophenoxyacetic acid (2.4-D) to BA-supplemented medium was obligatory
to develop somatic embryos. MS medium containing 2.26 μM 2,4-D and 4.44 μM BA induced a mean of 44.8 somatic embryos per proximal explant. The embryos passed through distinct stages of embryogenesis,
namely globular, heart, torpedo, and early cotyledonary. The embryos (88%) underwent maturation on half-strength MS medium
with 2.89 μM gibberellic acid (GA3), and its subsequent transfer on half-strength MS basal medium in light conditions facilitated 80% conversion of embryos
to plantlets. Direct shoots or embryos were originated from the mesophyll cells. Somatic embryo development was concurrent
with the independent origin of vasculature in the bulbous basal portion. The survival rate of embryo-derived plants was 90%. 相似文献
4.
Summary
In vitro propagation of Quassia amara L. (Simaroubaceae) was attempted using mature and juvenile explants. Attempts to establish in vitro culture using leaf and internode explants from a plant more than 15yr old were unsuccessful due to severe phenolic exudation.
Plant regeneration through direct and indirect somatic embryogenesis was established from cotyledon explants. Murashige and
Skoog (MS) medium with 8.9 μM N6-benzyladenine (BA) and 11.7 μM silver nitrate induced the highest number (mean of 32.4 embryos per cotyledon) of somatic embryos. Direct somatic embryogenesis
as well as callus formation was observed on medium with BA (8.9–13.3 μM). Semi-mature pale green cotyledons were superior for the induction of somatic embryos. Embryos developed from the adaxial
side as well as from the point of excision of the embryonic axis. More embryos were developed on the proximal end compared
to mid and distal regions of the cotyledons. Subculture of callus (developed along with the somatic embryos on medium with
BA alone) onto medium containing 8.9 μM BA and 11.7 μM silver nitrate produced a mean of 17.1 somatic embryos. Primary somatic embryos cultured on MS medium with 8.9 μM BA and 11.7μM silver nitrate produced a mean of 9.4 secondary somatic embryos. Most of the embryos developed up to early cotyledonary stage.
Reduced concentration of BA (2.2 or 4.4 μM) improved maturation and conversion of embryos to plantlets. Ninety percent of the embryos converted to plantlets. The optimized
protocol facilitated recovery of 30 plantlets per cotyledon explant within 80d. Plantlets transferred to small cups were subsequently
transferred to field conditions with a survival rate of 90%. 相似文献
5.
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
6.
Maurizio Lambardi Kiran K. Sharma Trevor A. Thorpe 《In vitro cellular & developmental biology. Plant》1993,29(4):189-199
Summary Studies were undertaken to optimize tissue culture conditions for micropropagation of Aleppo pine (Pinus halepensis Mill.) from mature embryos and various explants of the embryo. Over 90% of the embryo explants gave rise to adventitious
buds within 4 wk. Intact embryos were the most suitable explants for shoot bud induction. Both isolated cotyledons and hypocotyls
produced adventitious buds, but these developed slowly and failed to elongate. N6-Benzyladenine (BA) alone at 5.0μM was the most effective cytokinin when added to gelled to gelled von Arnold and Eriksson’s (AE) medium containing 3% sucrose.
Adventitious bud development was achieved on hormone-free AE medium, and shoot elongation was optimum on three quarter-strength
Bornman’s MCM medium, with 0.1% conifer-derived activated charcoal. Shoots were multiplied on three-quarter strength MCM medium,
containing 5μM BA. To induce adventitious roots on the elongated shoots, pulse treatment with 1 mM IBA for 6 h, followed by the transfer of the shoots to sterile peat:vermiculite (1:1) mixture, was beneficial. After acclimatization
for 3 to 4 wk under mist, almost all the rooted shoots could be transplanted successfully to the greenhouse, where the plants
exhibited normal growth habit. Histologic studies on the ontogeny of adventitious shoot formation from mature embryo explants
revealed temporal structural changes in different parts of the explant. Induction of mitotic divisions on the shoot-forming
medium resulted in the formation of meristemoids in the epidermal and subepidermal layers of the explant, located initially
at both the tips of the cotyledons and the axils of adjacent cotyledons. Shoot buds arising in the axils of adjacent cotyledons
were due to new cell division and not to any preexisting meristem. 相似文献
7.
Perera PI Hocher V Verdeil JL Doulbeau S Yakandawala DM Weerakoon LK 《Plant cell reports》2007,26(1):21-28
Unfertilized ovaries isolated from immature female flowers of coconut (Cocos nucifera L.) were tested as a source of explants for callogenesis and somatic embryogenesis. The correct developmental stage of ovary explants and suitable in vitro culture conditions for consistent callus production were identified. The concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) and activated charcoal was found to be critical for callogenesis. When cultured in a medium containing 100 μM 2,4-D and 0.1% activated charcoal, ovary explants gave rise to 41% callusing. Embryogenic calli were sub-cultured into somatic embryogenesis induction medium containing 5 μM abscisic acid, followed by plant regeneration medium (with 5 μM 6-benzylaminopurine). Many of the somatic embryos formed were complete with shoot and root poles and upon germination they gave rise to normal shoots. However, some abnormal developments were also observed. Flow cytometric analysis revealed that all the calli tested were diploid. Through histological studies, it was possible to study the sequence of the events that take place during somatic embryogenesis including orientation, polarization and elongation of the embryos. 相似文献
8.
A. Tirajoh T. S. Kyung Z. K. Punja 《In vitro cellular & developmental biology. Plant》1998,34(3):203-211
Summary Somatic embryogenesis in American ginseng (Panax quinquefolium L.) was investigated from three explant sources (root, leaf and epicotyl) with Murashige and Skoog (MS) medium containing
different growth regulators. Mature roots and leaves obtained from 3- to 5-yr-old field-grown plants, and seedling leaves
and epicotyls from plantlets grownin vitro, were evaluated. From root and epicotyl explants, callus development was optimal with 3,6-dichloro-o-anisic acid (dicamba)
(9.0 μM) and kinetin (KN) (5.0 μM) as the growth regulators. When these calluses were transferred after 3 mo. to dicamba alone (9.0 μM), somatic embryo formation was observed at an average frequency of 15.6% in root explants after an additional 3 mo., and
2% in epicotyl explants after an additional 6 mo. No plantlets were recovered because the embryos germinated to form shoots
with no roots. From leaf explants, callus growth was optimal with α-naphthaleneacetic acid (NAA) at 10.0 μM and 2,4-dichlorophenoxyacetic acid (2,4-D) at 9.0 μM. Somatic embryos developed on this medium, with the highest frequency (40%) obtained after 3 mo. from seedling-leaf explants.
Calluses on mature leaves formed somatic embryos after 7 mo. with NAA/2,4-D at an average frequency of 30%. Transfer of these
somatic embryos to 6-benzyladenine/gibberellic acid (4.4/2.9 μM) promoted shoot development but no roots were observed. Up to 100% of germination was observed within 6 wk on half-strength
MS salts containing activated charcoal (1%) and on NAA/2,4-D (5.0/4.5 μM) with charcoal (1%). On the latter medium, somatic embryos enlarged and frequently gave rise to new somatic embryos after
a brief callusing phase. The embryos germinated through a two-stage process, involving the elongation of the root followed
by the formation of a shoot. The highest recovery of ginseng plantlets from germinated embryos was 61.0%. Following transfer
to potting medium and maintenance under conditions of high humidity and low light intensity, the plantlets elongated and developed
new leaves. A high percentage (50%) of these plants have been acclimatized to soil. 相似文献
9.
Summary The embryogenic potential of different Echinacea purpurea tissues, viz. leaf, cotyledon, and root, was investigated. Maximum embryo-induction was achieved from leaf dises cultured
on Murashige and Skoog medium supplemented with benzylaminopurine (5.0 μM) and indolebutyric acid (2.5 μM) where 95% of the explants responded, yielding an average of 83 embryos per explant within 4 wk of culture. Incubation of
cultures in the dark for an initial period of 14 d significantly increased the frequency of somatic embryogenesis (6–8-fold
in leaf explants). Exposure of the abaxial surface of leaves to the medium significantly increased the number of embryos.
Transfer of somatic embryos to a medium devoid of growth regulators resulted in 80% germination within 7 d. Over 73% of the
somatic embryos developed roots within 28 d of culture on a medium containing naphthaleneacetic acid (10 μM) with a maximum root number of 9.8 per plantlet. Transplanting ex vitro and acclimatization for a period of 7 d were sufficient to promote establishment of plants in the greenhouse, and more than
90% of the regenerated plants survived. 相似文献
10.
Summary The effects of nodal explants collected at different plastochrones, use of various benzyladenine (BA) concentrations, sources
of carbohydrates, and phases of the culture medium on shoot establishment and proliferation ofRosa hybrida L. andR. chinensis minima were evaluated. Higher numbers of shoots per explant were obtained fromR. hybrida cv. Carefree Beauty explants proximal to the apical meristem than those from distal nodes. However, proliferating shoots
derived from plastochrones proximal to the apical meristem had a lower number of leaves/explant and were shorter than those
derived from other distal plastochrones. Although shoot proliferation increased with higher BA concentration in the medium,
a concentration of 4.4 μM BA was found optimum for axillary bud-break and shoot development forR. hybrida cvs. Adelaide Hoodless and Cuthert Grant. A higher shoot proliferation rate was observed forR. hybrida cv. Carefree Beauty explants grown on a medium containing 55.5 mM fructose than 58.4 mM sucrose. However, no differences were observed forR. hybrida cv. Cuthert Grant grown on a medium containing either fructose or sucrose. The mean number of shoots/explant was higher forR. chinensis minima cv. Red Sunblaze explants grown on a liquid (4.5) than on a solid medium (1.7) for the first reculture; while no significant
differences between the two phases of the medium were observed for the second reculture. However, a higher mean number of
shoots/explant was observed on solid-phase (4.0) than liquid-phase medium (3.4) for the third reculture. A higher mean number
of leaves/shoot was obtained on a solidified medium rather than liquid medium in the first two consecutive recultures, while
no differences were observed for the third reculture. Although a significant effect of BA concentration on mean number of
shoots/explant was observed for Red Sunblaze nodal explants, the influence of BA concentration decreased in the two consecutive
cultures for both phases of the medium. Hyperhydricity was observed on Red Sunblaze shoots grown on the liquid-phase medium. 相似文献
11.
P. Giridhar Vinod Kumar G. A. Ravishankar 《In vitro cellular & developmental biology. Plant》2004,40(6):567-571
Summary A novel protocol has been developed for inducing somatic embryogenesis from leaf cultures of Decalepis hamiltonii. Callus was obtained from leaf sections in Murashige and Skoog (MS) medium supplemented with α-naphthaleneacetic acid (NAA)+N6-benzyladenine (BA) or 2,4-dichlorophenoxyacetic acid (2,4-D)+BA. Nodular embryogenic callus developed from the cut end of
explants on media containing 2,4-D and BA, whereas compact callus developed on media containing NAA and BA. Upon subsequent
transfer of explants with primary callus onto MS media containing zeatin and/or gibberellic acid (GA3) and BA, treatment with zeatin (13.68μM) and BA (10.65 μM) resulted in the induction of the highest number of somatic embryos directly from nodular tissue. The maturation of embryos
took place along with the induction on the same medium. Embryogenic calluses with somatic embryos were subcultured onto MS
basal medium supplemented with 4.56μM zeatin+10.65 μM BA. After 4wk, more extensive differentiation of somatic embryos was observed. The mature embryos developed into complete
plantlets on growth regulator-free MS medium. A distinct feature of this study is the induction of somatic embryogenesis from
leaf explants of Decalepis hamiltonii, which has not been reported previously. By using this protocol, complete plantlets could be regenerated through indirect
somatic embryogenesis or organogenesis from leaf explants in 12–16 wk. 相似文献
12.
Marie-Claire D'Souza Madhuri Sharon 《In vitro cellular & developmental biology. Plant》2001,37(2):168-172
Summary A protocol for in vitro propagation of Bixa orellana is described. Plants were regenerated from shoot apex and nodal explants on B5 medium supplemented with 4.9 μM 2-isopentenyl adenine. The multiplication factor of shoot apex explants was higher (nine shoots per explant) than that of
the nodal explants (five shoots per explant). Regardless of the position of the nodes, all the nodal explants gave similar
responses. However, the size of the nodal explant was an important factor in producing multiple shoots: 0.5 cm nodal explants
produced the maximum multiple shoots. Regenerated shoots from shoot apex explants rooted best on MS medium supplemented with
0.05 μM α-naphthalene acetic acid (NAA). whereas shoots regenerated from nodal explants needed 2.7 μM NAA for rooting. Eighty per cent survival of in vivo transferred plants occurred on the best potting substrate, coco peat. Since the multiplication factor was nine per explant,
this protocol can be use for commercial microprogation. However, the regeneration capacity declined after 10 subcultures.
Approximately, 3350 rooted plants could be generated in 10 mo. after eight subcultures, from one shoot with a shoot apex and
four nodes. 相似文献
13.
Summary Micropropagation of Scabiosa caucasica cv. Caucasica Blue was achieved by culturing, separating axillary and adventitious shoots, or node sectioning on Murashige
and Skoog (MS) medium supplemented with benzyladenine (BA). The highest frequency of adventitious shoots regenerated from
nodal or internodal explants and leaf blade (with or without petiole) appeared to occur on MS medium with 4.4 and 18 μM BA, respectively. Addition of 0.19 or 1.9 μM α-naphthaleneacetic acid to the BA-containing medium promoted callus formation and reduced shoot organogenesis. During micropropagation,
shoot nodal explants derived from in vitro shoots cultured on MS medium supplemented with 4.4 μM BA yielded 8.9 shoots per explant within 40 d after culture initiation. 相似文献
14.
Solange Faria Lua Figueiredo Norma Albarello Vera Regina Campos Viana 《In vitro cellular & developmental biology. Plant》2001,37(4):471-475
Summary A protocol for in vitro propagation of Rollinia mucosa, an important medicinal plant, was developed. The presence of 500 mg l−1 polyvinylpyrrolidone (PVP) during explant excision was important to avoid browning. Axillary buds, adventitious buds, and
shoot cluster proliferation were achieved from epicotyl and hypocotyl explants from nursery-grown seedlings. The highest direct
organogenesis percentage from hypocotyl explants was obtained upon culture of explants on Murashige and Skoog medium supplemented
with 2.2 μM benzyladenine (BA) plus 2.32 μM kinetin. Epicotyl explants display highest regeneration frequency on a medium containing 8.8 μM BA and 0.54 μM naphthaleneacetic acid. Gibberellic acid was necessary for shoot elongation. Root induction was observed when shoots were
pretreated with activated charcoal for 7 d in the dark before culture on Woody Plant Medium supplemented with 49.21 μM indolebutyric acid for 10 d. Root development was observed when 20 g l−1 sucrose was used. Rooted plantlets were acclimatized and grown in the greenhouse. 相似文献
15.
Zhijian Li Abdoulaye Traore Siela Maximova Mark J. Guiltinan 《In vitro cellular & developmental biology. Plant》1998,34(4):293-299
Summary A procedure for the regeneration of cacao (Theobroma cacao) plants from staminode explants via somatic embryogenesis was developed. Rapidly growing calli were induced by culturing
staminode explants on a DKW salts-based primary callus growth (PCG) medium supplemented with 20 g glucose per L, 9 μM 2,4-D, and thidiazuron (TDZ) at various concentrations. Calli were subcultured onto a WPM salts-based secondary callus growth
medium supplemented with 20 g glucose per L, 9 μM 2,4-D, and 1.4 nM kinetin. Somatic embryos were formed from embryogenic calli following transfer to a hormone-free DKW salts-based embryo development
medium containing sucrose. The concentration of TDZ used in PCG medium significantly affected the rate of callus growth, the
frequency of embryogenesis, and the number of somatic embryos produced from each responsive explant. A TDZ concentration of
22.7 nM was found to be the optimal concentration for effective induction of somatic embryos from various cacao genotypes. Using
this procedure, we recovered somatic embryos from all 19 tested cacao genotypes, representing three major genetic group types.
However, among these genotypes, a wide range of variation was observed in both the frequency of embryogenesis, which ranged
from 1 to 100%, and the average number of somatic embryos produced from each responsive explant, which ranged from 2 to 46.
Two types of somatic embryos were identified on the basis of their visual appearance and growth behavior. A large number of
cacao plants have been regenerated from somatic embryos and established in soil in a greenhouse. Plants showed morphological
and growth characteristics similar to those of seed-derived plants. The described procedure may allow for the practical use
of somatic embryogenesis for clonal propagation of elite cacao clones and other applications that require the production of
a large number of plants from limited source materials. 相似文献
16.
Summary
In vitro propagation of Andrographis paniculata (Burm. f.) Wallich ex Nees through somatic embryogenesis, and influence of 2,4-dichlorophenoxyacetic acid (2,4-1) on induction, maturation, and
conversion of somatic embryos were investigated. The concentration of 2,4-D in callus induction medium determined the induction,
efficacy of somatic embryogenesis, embryo maturation, and conversion. Friable callus initiated from leaf and internode explants
grown on Murashige and Skoog (MS) medium supplemented with 2.26, 4.52, 6.78, and 9.05μM 2,4-D started to form embryos at 135, 105, 150, and 185d, respectively, after explant establishment. Callus initiated at
13.56μM 2,4-D did not induce embryos even after 240 d, whereas those initiated on MS medium with 4.52μM 2,4-D was most favorable for the formation and maturation of somatic embryos. Callus subcultured on the medium with reduced
concentration of 2,4-D (2.26μM) became embryogenic. This embryogenic callus gave rise to the highest number of embryos (mean of 312 embryos) after being
transferred to half-strength MS basal liquid medium. The embryos were grown only up to the torpedo stage. A higher frequency
of embryos developed from callus initiated on 2.26 or 4.52 μM 2,4-D underwent maturation compared to that initiated on higher concentrations of 2.4-D. The addition of 11.7μM silver nitrate to half-strength MS liquid medium resulted in 71% of embryos undergoing maturation, while 83% of embryos developed
into plantlets after being transferred to agar inedium with 0.44 μMN6-benzyladenine and 1.44 μM gibberellic acid. Most plantlets (88%) survived under field conditions and were morphologically identical to the parent plant. 相似文献
17.
Dong-Ho Shin Jin Sook Kim In Jeong Kim Jaemo Yang Soo Kyung Oh Gab Chae Chung Kyung-Hwan Han 《In vitro cellular & developmental biology. Plant》2000,36(4):273-278
Summary We describe a protocol, and several experiments that helped lead to its development, for sunflower regeneration. Important
factors for sunflower regeneration were explant age, cytokinin type and concentration, basal medium, and explant source. We
could not induce shoot regeneration from the explants derived from mature tissues including leaf, petiole, and stem. However,
use of juvenile explants such as embryo meristem and primordial leaf tissues allowed routine regeneration of 17 different
sunflower genotypes. High frequency of shoot regeneration was achieved with these explants taken from seedlings up to 5 d
after germination. Explant age was less critical for embryo meristem explants than for primordial leaf tissues. Of the four
basal media tested, MS and B5 media produced higher shoot-regeneration frequencies than did Anderson and woody plant media.
The highest shoot-regeneration frequency was obtained with MS medium supplemented with 2 μM BA and without auxin. Addition of 1 μM naphthalene-acetic acid to the medium significantly reduced both the percentage of explants producing shoots and average
number of shoots per explant. Regenerated shoots were grown to maturity in a greenhouse. 相似文献
18.
Summary Efficient in vitro propagation of Ceropegia candelabrum L. (Asclepidaceae) through somatic embryogenesis was established. Somatic embryogenesis depended on the type of plant growth
regulators in the callus-inducing medium. Friable callus, developed from leaf and internode explants grown on Murashige and
Skoog (MS) medium supplemented with 4.52μM2,4-dichlorophenoxyacetic acid (2,4-D), underwent somatic embryogenesis. Compared to solid media, suspension culture was superior
and gave rise to a higher number of somatic embryos. Transfer of the friable callus developed on MS medium containing 4.52μM 2,4-D to suspension cultures of half- or quarter-strength MS medium with lower levels of 2,4-D (0.23 or 0.45 μM) induced the highest number of somatic embryos, which developed up to the torpedo stage. Somatic embryogenesis was asynchronous
with the dominance of globular embryos. About 100 mg of callus induced more than 500 embryos. Upon transfer to quarter-strength
MS agar medium without growth regulators, 50% of the somatic embryos underwent maturation and developed into plantlets. Plantlets
acclimatized under field conditions with 90% survival. 相似文献
19.
P. G. Golegaonkar A. S. Kantharajah 《In vitro cellular & developmental biology. Plant》2006,42(4):341-344
Summary
In vitro plantlet regeneration was obtained from cultured cotyledon and young leaf explants of five Indian chile pepper cultivars
(Capsicum annuum L. evs. Gujarat-1, Gujarat-2, Guntur-4, Selection-49, and Jwala). Adventitious shoot buds (ASB) were regenerated directly
from cotyledon and young leaf explants in all the five cultivars on media containing benzyladenine (BA) alone or in combination
with 1-naphthaleneacetic acid (NAA). Regeneration frequency was highly influenced by cultivar explant type, media combination
and their interactions, except the interaction between cultivar and explant, for number of ASB per explant. Percent contribution
of individual source suggested that selection of explant type followed by medium combination and cultivars was essential for
obtaining high-frequency ASB induction. Across different cultivars the young leaf explant was found to be the most responsive
explant, while Murashige and Skoog (MS) medium containing BA alone (17.8, 26.6, and 35.5 μM) was found to be the best medium for the production of maximum number of ASB. Between the two explants, shoot elongation
was observed with ASB obtained from young leaf explants on MS medium containing BA (2.2 and 4.4 μM) and gibberellie acid (GA3) (1.4, 2.9, 4.3 and 5.8 μM). The MS medium fortified with 4.4 μM BA+2.9μM GA3 was optimum for shoot elongation. Elongated shoots were rooted on liquid MS medium supplemented with 2.9 μM indole-3-acetic acid (IAA) and successfully established ex vitro. 相似文献
20.
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