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1.
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
2.
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
3.
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
4.
Chun-Lai Zhang Dong-Fang Chen Malcolm C. Elliott Adrian Slater 《In vitro cellular & developmental biology. Plant》2001,37(2):305-310
Summary Improved in vitro tissue culture systems are needed to facilitate the application of recombinant DNA technology to the improvement of sugar
beet germplasm. The effects of N
6-benzyladenine (BA) and thidiazuron (TDZ) pretreatment on adventitious shoot and somatic embryogenesis regeneration were evaluated
in a range of sugar beet breeding lines and commercial varieties. Petiole explants showed higher frequencies of direct adventitious
shoot formation and produced more shoots per explant than leaf lamina explants. TDZ was more effective than BA for the promotion
of shoot formation. The optimal TDZ concentrations were 2.3–4.6 μM for the induction of adventitious shoot regeneration. Direct somatic embryogenesis from intact seedlings could be induced
by either BA or TDZ. TDZ-induced somatic embryogenesis occurred on the lower surface of cotyledons at concentrations of 0.5–2μM and was less genotype-dependent than with Ba. A high frequency of callus induction could be obtained from seedlings and leaf
explants, but only a few of the calluses derived from leaf explants could regenerate to plants via indirect somatic embryogenesis. These results demonstrated that TDZ could prove to be a more effective cytokinin for in vitro culture of sugar beet than BA. Rapid and efficient regeneration of plants using TDZ may provide a route for the production
of transgenic sugar beet following Agrobacterium-mediated transformation. 相似文献
5.
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
6.
Murugesan Dhandapani Doo Hwan Kim Seung-Beom Hong 《In vitro cellular & developmental biology. Plant》2008,44(1):18-25
High-frequency plant regeneration of C. roseus cv. ‘little bright eye’ via somatic embryogenesis and organogenesis from five out of six explants was standardized. Two factors
were found to be important for regeneration: (1) the type of explants, and (2) the combination and concentrations of plant
growth regulators. The highest regeneration percentage through somatic embryogenesis was obtained from mature zygotic embryo
in MS medium supplemented with 7.5 μM of thidiazuron (TDZ). The mature embryo also regenerated efficiently via organogenesis
in MS medium supplemented with either 2.5 μM TDZ or 5.3 μM α-naphthalene acetic acid (NAA) and 2.2 μM 6-benzylaminopurine
(BA). Hypocotyl and cotyledon did not induce somatic embryogenesis and organogenesis in TDZ-containing medium but gave a maximum
percentage of shoots in MS medium supplemented with 5.3 μM NAA and 2.2 μM BA. Stem nodes and meristem tips showed better regeneration
via organogenesis in the medium supplemented with NAA and BA and in lower concentrations of TDZ. 相似文献
7.
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
8.
Jenks Matthew A. Kane Michael E. McConnell Dennis B. 《Plant Cell, Tissue and Organ Culture》2000,61(1):1-8
A protocol for rapid shoot organogenesis from petiole explants of the ornamental aquatic plantNymphoides indica L. Thwaites O. Kuntze was developed for use in future mutation breeding and cultivar selection studies. Optimum culture conditions
for shoot organogenesis were determined. Effects of factorial combinations of 2-iP, BA or kinetin (0–25 μM) in factorial combination
with IAA or NAA (0–25 μM) were examined. On the basis of regeneration frequency (80%) and adventitious shoot number (11.5
shoots per explant), most efficient shoot organogenesis occurred on petiole explants cultured on a basal medium consisting
of full-strength MS inorganic salts, 0.56 mM myo-inositol, 1.2 μM thiamine-HCl, 116.8 mM sucrose supplemented with 10 μM BA
and 20 μM IAA and solidified with 0.8% TC agar. Formation of adventitious shoots by direct and indirect shoot organogenesis
from the same explant was verified by histological sectioning. With the exception of variegated leaf production on a single
adventitious shoot produced in the presence of 25 μM kinetin and 15 μM NAA, no visible phenotypic abnormalities were observedin vitro in any of the shoots generated. Solid achlorophyllous adventitious shoots were recovered following culture of this variegated
leaf tissue. Plantlets were easily acclimatized toex vitro conditions.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
9.
Pretreatment in thidiazuron improves the in vitro shoot induction from leaves in Curculigo orchioides Gaertn., an endangered medicinal plant 总被引:1,自引:0,他引:1
T. Dennis Thomas 《Acta Physiologiae Plantarum》2007,29(5):455-461
Leaf regeneration via direct induction of adventitious shoots obtained from an endangered medicinal plant, Curculigo orchioides Gaertn. by pretreating with thidiazuron. C. orchioides is an endangered medicinal herb belonging to the family Hypoxidaceae. Direct inoculation of leaf pieces on MS medium supplemented
with various concentrations of BAP (2–8 μM) or TDZ (2–8 μM) alone or in combination with NAA (0.5 and 1.0 μM) produced low
shoot induction both in terms of % response and number of shoots per explant. Hence, leaf explants were pretreated with 15,
25 or 50 μM thidiazuron (TDZ), for 6, 24 or 48 h with the aim of improving shoot regeneration from cultured explants. After
pretreatment, explants were transferred to an agar solidified MS medium that was supplemented with BAP (4 μM), TDZ (6 μM),
BAP (4 μM) + NAA (1.0 μM), TDZ (6 μM) + NAA (0.5 μM). Control explants were incubated directly on the medium without any pretreatment.
The pretreatment of explants with 15 μM TDZ for 24 h significantly promoted the formation of adventitious shoots and the maximum
response was observed on MS medium supplemented with 6 μM TDZ. In this medium, 96 % cultures responded with an average number
of 16.2 adventitious shoots per explant. The percentage of leaf explants producing shoots and the average number of shoots
per explant were significantly improved when TDZ pretreated leaves were cultured onto MS medium supplemented with BAP or TDZ
alone or in combination with NAA. The rooted plantlets were successfully transplanted to soil with 90% success. The present
investigation indicated the stimulatory role of TDZ pretreatment in regulating shoot regeneration from leaf explants of C. orchioides. 相似文献
10.
Summary Protocols for both axillary bud proliferation and shoot organogenesis of Euphorbia pulchurrima Winter RoseTM were developed using terminal buds and leaf tissues. Greenhouse-grown terminal buds were placed on Murashige-Skoog (MS) basal
medium supplemented with various concentrations of either benzlyaminopurine (BA) or thidiazuron (TDZ). Explants produced the
greatest number of axillary buds on media containing between 2.2 and 8.8 μM BA. The number of explants that produced axillary buds increased with increasing BA concentration. TDZ at concentrations
between 2.3 and 23.0 μM caused hyperhydricity of shoots and were not effective in promoting shoot proliferation. The most calluses and shoots were
produced from leaf midvein sections from in vitro grown plants placed on the medium containing 8.8–13.3 μM BA and 17.1 μM indole-3-acetic acid (IAA) for 1 mo. before transferring to the medium containing only BA. Adventitious buds were produced
only from red-pigmented callus, and explants that produced callus continued to produce adventitious shoots in the presence
of IAA. Five-mo.-old shoots derived from shoot culture or organogenesis rooted readily in artificial soil with or without
treatment with indolebutyric acid, and were acclimatized in the greenhouse. 相似文献
11.
Summary Adventitious shoot induction and elongation was compared between root and petiole explants of Kentucky coffeetree (Gymnocladus dioicus L.) explants treated with a factorial combination of benzylaminopurine (BA) and thidiazuron (TDZ). Petiole explants initiated
more adventitious shoots compared to root explants. Up to 83% of petiole explants initiated shoots compared to 67% of root
explants. Maximal shoot induction was approximately 12 or five shoots per responding explant for petiole and root explants,
respectively. For both explant types, TDZ was more effective than BA for shoot induction. There was an interaction between
BA and TDZ on shoot induction in petiole explants, with the greatest percentage of explants forming shoots and the highest
number of shoots initiated on the combination of 0.5 μM TDZ plus 10μM BA and 1.0μM TDZ plus 5 or 10 μM BA. In contrast, increasing concentrations of BA inhibited shoot initiation in root explants with and without TDZ. While
BA inhibited shoot initiation in root explants, it promoted shoot initiation in petiole explants. In contrast, TDZ was equally
effective at inducing shoots in root and petiole explants. This suggests that root and petiole explants of Kentucky coffeetree
could be a useful model system for studying the differences, in apparent mode of action between TDZ and BA on adventitious
shoot initiation. 相似文献
12.
An efficient micropropagation system via direct shoot organogenesis from hypocotyl segments of Embelia ribes Burm F. was developed. A high frequency (84%) of adventitious shoot induction was obtained on Murashige and Skoog (MS) medium
supplemented with additives (283.85 μM ascorbic acid [AA], 118.96 μM citric acid [CA], 142.33 μM cysteine, and 684.22 μM glutamine)
and 1.13 μM of thidiazuron (TDZ) after 4 weeks following culture. Further development of shoot primordia into well-grown shoots
of 4–5 cm in length was achieved by sub-culturing explants along with shoot primordia on MS medium supplemented with 0.44 μM
benzyl adenine (BA) and 0.49 μM indole butyric acid (IBA) for three sub-culture periods with an interval of 15 days between
them. The highest shoot multiplication was obtained when explants were incubated on MS medium supplemented with 2.2 μM BA
and 0.49 μM IBA in 4 weeks. All in vitro developed shoots, 3–4 cm in length, rooted when grown on half-strength MS basal medium
along with 2.47 μM IBA within 4 weeks. Moreover, 100% of shoots developed roots when these were treated with 4.93 μM IBA for
20 min and then transferred to pots containing soilrite mix and grown in the greenhouse. In vitro and ex vitro rooted plants
showed a survival of 85 and 95% respectively, during hardening in the greenhouse for a 6-week period. 相似文献
13.
Attempts were made to study the effect of thidiazuron (TDZ) on adventitious shoot induction and plant development in Paulownia tomentosa explants derived from mature trees. Media with different concentrations of TDZ in combination with an auxin were used to
induce adventitious shoot-buds in two explant types: basal leaf halves with the petiole attached (leaf explant) and intact
petioles. Optimal shoot regeneration was obtained in leaf explants cultured on induction medium containing TDZ (22.7 or 27.3 μM)
in combination with 2.9 μM indole-3-acetic acid (IAA) for 2 weeks, and subsequent culture in TDZ-free shoot development medium
including 0.44 μM BA for a further 4-week period. The addition of IAA to the TDZ induction medium enhanced the shoot-forming
capacity of explants. The caulogenic response varied significantly with the position of the explant along the shoot axis.
The highest regeneration potential (85–87%) and shoot number (up to 17.6 shoots/explant) were obtained in leaf explants harvested
from the most apical node exhibiting unfolded leaves (node 1). An analogous trend was also observed in intact petiole explants,
although shoot regeneration ability was considerably lower, with values ranging from 15% for petioles isolated from node 1
to 5% for those of nodes 2 and 3. Shoot formation capacity was influenced by the genotype, with regeneration frequencies ranging
from 50% to 70%. It was possible to root elongated shoots (20 mm) in basal medium without growth regulators; however, rooting
frequency was significantly increased up to 90% by a 7-day treatment with 0.5 μM indole-3-butyric acid, regardless of the
previous culture period in shoot development medium (4 or 8 weeks). Shoot quality of rooted plantlets was improved not only
by IBA treatment but also by using material derived from the 4-week culture period. Regenerated plantlets were successfully
acclimatized in the greenhouse 8 weeks after transplanting. 相似文献
14.
Burma reed (Neyraudia arundinacea Henr.) is a C4 grass native to Southeast Asia and Indomalaya that grows quickly, exhibits strong resistance to environmental stresses, and
is extremely adaptable. It can be widely utilized as a bioenergy crop for biomass conversion. In vitro multiple shoots were
first established from axillary buds and then subcultured on propagation medium containing 10 μM 6-benzylaminopurine (BA)
and 2.0 μM naphthaleneacetic acid (NAA). Multishoot clumps were used as explants to induce somatic embryogenesis and adventitious
shoot formation. The results showed that auxin 2,4-dichlorophenoxyacetic acid or NAA play a key role for the induction of
somatic embryogenesis and adventitious shoot formation, whereas cytokinin BA or kineatin enhance shoot proliferation and plant
regeneration from callus and somatic embryos. Efficient somatic embryogenesis, mass propagation, and plant regeneration systems
in Burma reed were established. 相似文献
15.
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
16.
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
17.
Xiuli Shen Michael E. Kane Jianjun Chen 《In vitro cellular & developmental biology. Plant》2008,44(4):282-288
The capacity for indirect shoot organogenesis of leaf and root explants of four Dieffenbachia cultivars were examined on a modified Murashige and Skoog (MS; Physiol Plant 15:473–495, 1962) medium supplemented with different plant growth regulators in 112 combinations. Callus formation was only observed from
leaf explants on MS supplemented with 1–10 μM thidiazuron (TDZ) and 0.5–1.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D) regardless
of cultivars. The combination of 5 μM TDZ and 1 μM 2,4-D resulted in the greatest callus formation frequency among the four
cultivars tested. Significant differences in callus and shoot formation from leaf explants were also observed among cultivars.
Cultivars Camouflage, Camille, Octopus, and Star Bright produced green nodular, brown nodular, yellow friable, and green compact
calli with corresponding maximum callus formation frequencies of 96%, 62%, 54%, and 52%, respectively. A maximum of 6.7 shoots/callus
was observed in cv. Camouflage, followed by cvs. Camille and Star Bright at 3.7 and 3.5, respectively. Calli of cv. Octopus
displayed no capacity for shoot organogenesis. Regardless of cultivar, callus formation was not observed on root explants.
Regenerated shoots were successfully acclimatized in a shaded greenhouse condition with 100% survival. 相似文献
18.
The macadamia tree, an Australian native, is highly valued for its nuts. Macadamia improvement programs so far have relied on conventional breeding and selection. The production of improved cultivars required to meet future demands could be accelerated by the application of modern biotechnological techniques, but this requires an efficient and reproducible regeneration system that has not yet been established for macadamia. We report here shoot regeneration from immature cotyledon explants of macadamia. Adventitious buds were induced on the cotyledon explants from fruits collected at 140 and 190 days after full bloom (DAFB) on MS medium supplemented with either 10 or 15 μM TDZ. The addition of 2% coconut milk (CM) to 10 μM TDZ containing media resulted in enhanced adventitious bud induction from 190 DAFB explants. Further shoot development from the induced buds was depressed in media containing TDZ + CM; the addition of 0.001 μM IAA to this combination doubled shoot development, from 1.9–3.9 shoots per explant. The transfer of bud clumps to media supplemented with 8.8 μM BA alone or in combination with either 0.14 μM GA3 or 0.001 μM IAA significantly increased shoot production from the previously induced explants by 1.5–2 times of that observed in TDZ + CM medium. Histological examinations revealed that shoot regeneration was primarily by organogenesis originating from cells on or just below the cut surfaces of explants. 相似文献
19.
Veena Agrawal Pratima Rani Sardar 《In vitro cellular & developmental biology. Plant》2007,43(6):585-592
In vitro regeneration through somatic embryogenesis as well as organogenesis using cotyledon of a woody medicinal legume, Cassia angustifolia is reported. The cotyledons dissected from semi-mature seeds, if inoculated on Murashige and Skoog’s medium (MS) supplemented
with auxin alone or in combination with cytokinin, produced direct and indirect somatic embryos. A maximum of 14.36 ± 2.26
somatic embryos per 20 mg of explants including callus were produced in 70% cultures on MS medium with 2.5 μM benzyladenine
(BA) + 10 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Although the percentage of embryogenic cultures was higher (83.33%) at
10 μM 2,4-D + 1 μM BA, the average number of somatic embryos was much less (7.6 ± 0.85) at this level, whereas at 2.5 μM BA
and 5 μM 2,4-D, there was a simultaneous formation of both somatic embryos and shoots. The somatic embryos, although started
germinating on the same medium, developed into full plantlets only if transferred to MS basal with 2% sucrose. Cytokinins
alone did not induce somatic embryogenesis, but formed multiple shoots. Five micromolar BA proved optimum for recurrently
inducing shoots in the competent callus with a maximum average of 12.04 ± 2.10 shoots and shoot length of 2.26 ± 0.03 cm.
Nearly 91.6% shoots (2–2.5 cm in size) organized an average of 5.12 ± 0.58 roots on half strength MS + 10 μM indole-3-butyric
acid. All the plantlets have been transferred successfully to soil. Types of auxin and its interaction with cytokinin significantly
influenced somatic embryogenesis. 相似文献
20.
Muthu Thiruvengadam K. T. Rekha Chang-Hsien Yang Narayanasamypillai Jayabalan Ill-Min Chung 《Plant biotechnology reports》2010,4(4):321-328
An efficient protocol for in vitro organogenesis was achieved from callus-derived immature and mature leaf explants of Momordica charantia, a very important vegetable and medicinal plant. Calluses were induced from immature leaf explants excised from in vitro
(15-day-old seedlings) mature leaf explants of vivo plants (45 days old). The explants were grown on Murashige and Skoog (MS)
medium with Gamborg (B5) vitamins containing 30 g l−1 sucrose, 2.2 g l−1 Gelrite, and 7.7 μM naphthalene acetic acid (NAA) with 2.2 μM thidiazuron (TDZ). Regeneration of adventitious shoots from
callus (30–40 shoots per explant) was achieved on MS medium containing 5.5 μM TDZ, 2.2 μM NAA, and 3.3 μM silver nitrate (AgNO3). The shoots (1.0 cm length) were excised from callus and elongated in MS medium fortified with 3.5 μM gibberellic acid (GA3). The elongated shoots were rooted in MS medium supplemented with 4.0 μM indole 3-butyric acid (IBA). Rooted plants were
acclimatized in the greenhouse and subsequently established in soil with a survival rate of 90%. This protocol yielded an
average of 40 plants per leaf explant with a culture period of 98 days. 相似文献