共查询到20条相似文献,搜索用时 750 毫秒
1.
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
2.
M. A. K. Azad S. Yokota F. Begum N. Yoshizawa 《In vitro cellular & developmental biology. Plant》2009,45(4):441-449
Somatic embryogenesis and subsequent plant regeneration were established from hypocotyl and internode explants collected from
in vitro-grown seedlings and in vitro-proliferated shoots, respectively. Somatic embryogenesis was significantly influenced by the types of auxin and cytokinin.
Friable calluses with somatic embryos developed well in Murashige and Skoog basal (MS) medium supplemented with 0.8–8.8 μM
6-benzylaminopurine (BA) and 2.0–8.0 μM 2,4-dichlorophexoxyacetic acid (2,4-D) or α-naphthaleneacetic acid (NAA). The maximal
frequency of embryogenic callus and somatic embryo formation were obtained when the MS medium was amended with 8.8 μM BA and
4.0 μM 2,4-D. The best embryo germination occurred in a hormone-free 1/2-MS medium. The highest percentage of shoot proliferation
was observed in embryogenic calluses in MS medium containing 2.0 μM BA and 1.0 μM NAA. In vitro-grown shoots were rooted in MS medium with 0.5–2.0 μM indole-3-butyric acid. Regenerants were transferred to vermiculite and
successfully established under an ex vitro environment in garden soil. 相似文献
3.
Shyamkumar Barampuram Byung Yeoup Chung Seung Sik Lee Byung Chull An Eun Mi Lee Jae-Young Cho 《In vitro cellular & developmental biology. Plant》2009,45(2):155-161
The present study demonstrates the establishment of embryogenic tissue from seeds and (seedling-derived hypocotyls) shoot
base explants derived from seedlings of Eremochloa ophiuroides. The highest percentage of callus induction obtained from seed and young shoot base explants was 52.0% and 66.6% on Murashige
and Skoog (MS) basal media supplemented with 9.0 μM and 18.1 μM 2,4-dichlorophenoxyacetic acid (2,4-D), respectively. The
type of callus obtained from both types of explants was off-white to yellow in color and non-friable and shiny in texture.
Excised callus from the explants was subcultured onto fresh media of the same recipe for further proliferation. After 10–12 d
of subculture, a yellow, globular, friable embryogenic callus was obtained from the initial callus. The highest percentage
of embryogenic calli obtained at 40.0% was observed on media containing 2.2 μM 2,4-D. The highest regeneration rate of 46.6%
was observed on MS media supplemented with 0.4 μM 2,4-D and 2.2 μM benzylaminopurine (BA). Regenerated shoots were rooted
in MS basal medium. Plants with well-developed roots were transferred to pots containing a soil mix and acclimatized in greenhouse
conditions. Four weeks post-transfer, acclimatized plants showed 100% survival and remained healthy and green. This is the
first report of a successful method for induction of somatic embryogenesis with subsequent plant regeneration in centipede
grass and demonstrates the establishment of embryogenic callus and efficient plant regeneration with potential application
in the development of genetic transformation systems for centipede grass. 相似文献
4.
Jin Cui Jianjun Chen Richard J. Henny 《In vitro cellular & developmental biology. Plant》2009,45(1):34-43
Plant regeneration through direct somatic embryogenesis in Aeschynanthus radicans ‘Mona Lisa’ was achieved in this study. Globular somatic embryos were formed directly from cut edges of leaf explants and
cut ends or on the surface of stem explants 4 wk after culture on Murashige and Skoog (MS) medium supplemented with N-phenyl-N′-1, 2, 3-thiadiazol-5-ylurea (TDZ) with α-naphthalene acetic acid (NAA), TDZ with 2,4-dichlorophenoxyacetic acid (2,4-D),
or 6-benzylaminopurine (BA) or kintin (KN) with 2,4-D. MS medium containing 9.08 μM TDZ and 2.68 μM 2,4-D resulted in 71%
of stem explants producing somatic embryos. In contrast, 40% of leaf explants produced somatic embryos when induced in medium
containing 6.81 μM TDZ and 2.68 μM 2,4-D. Somatic embryos matured, and some germinated into small plants on the initial induction
medium. Up to 64% of stem explants cultured on medium supplemented with 9.08 μM TDZ + 2.68 μM 2,4-D, 36% of leaf explants
cultured on medium containing 6.81 μM TDZ and 2.68 μM 2,4-D had somatic embryo germination before or after transferring onto
MS medium containing 8.88 μM BA and 1.07 μM NAA. Shoots elongated better and roots developed well on MS medium without growth
regulators. Approximately 30–50 plantlets were regenerated from each stem or leaf explant. The regenerated plants grew vigorously
after transplanting to a soil-less substrate in a shaded greenhouse with more than a 98% survival rate. Three months after
their establishment in the shaded greenhouse, 500 plants regenerated from stem explants were morphologically evaluated, from
which five types of variants that had large, orbicular, elliptic, small, and lanceolate leaves were identified. Flow cytometry
analysis of the variants along with the parent showed that they all had one identical peak, indicating that the variant lines,
like the parent, were diploid. The mean nuclear DNA contents of the variant lines and their parent ranged from 4.90 to 4.99 pg
2C−1, which were not significantly different statistically. The results suggest that the regenerated plants have a stable ploidy
level, and the regeneration method established in this study can be used for rapid propagation of ploidy-stable Aeschynanthus radicans. 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.
Jonny E. Scherwinski-Pereira Rodrigo S. da Guedes Paulo César P. FerminoJr Tatiane L. Silva Frederico Henrique S. Costa 《In vitro cellular & developmental biology. Plant》2010,46(4):378-385
An efficient procedure has been developed for inducing somatic embryogenesis and regeneration of plants from tissue cultures
of oil palm (Elaeis guineensis Jacq.). Thin transverse sections (thin cell layer explants) of different position in the shoot apex and leaf sheath of oil
palm were cultivated in Murashige and Skoog (MS) (Physiol Plant 15:473–497, 1962) medium supplemented with 0–450 μM picloram and 2,4-D with 3.0% sucrose, 500 mg L−1 glutamine, and 0.3 g L−1 activated charcoal and gelled with 2.5 g L−1 Phytagel. Embryogenic calluses were evaluated 12 wk after inoculation. Picloram (450 μM) was effective in inducing embryogenic
calluses in 41.5% of the basal explants. Embryogenic calluses were maintained on a maturation medium composed of basal media,
plus 0.6 μM NAA and 12.30 μM 2iP, 0.3 g L−1 activated charcoal, and 500 mg L−1 glutamine, with subcultures at 4-wk intervals. Somatic embryos were converted to plants on MS medium with macro- and micronutrients
at half-strength, 2% sucrose, and 1.0 g L−1 activated charcoal and gelled with 2.5 g L−1 Phytagel. 相似文献
7.
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
8.
Rishi K. Tyagi Rajni Goswami Rajkumari Sanayaima Rakesh Singh Rajesh Tandon Anuradha Agrawal 《In vitro cellular & developmental biology. Plant》2009,45(6):721-729
Cardamom (Elettaria cardamomum Maton) has great commercial value as a spice crop in India. A one-step protocol for direct regeneration of plants and in vitro conservation by slow growth method has been developed. A maximum of 6.5 shoots/culture were obtained in 2 mo or 15.1 shoots/culture
in 4 mo on Murashige and Skoog (Physiol Plant 15:473–497, 1962) medium (MS) + 5 μM benzylaminopurine gelled with 0.7% agar (micropropagation medium). Rooting also occurred simultaneously
on the same medium. Using one shoot tip or nodal explant, about 30,375 plants can be regenerated in a year on the micropropagation
medium. In vitro conservation by slow growth method was achieved on 1/2 MS (major salts) + 5 μM BAP + 0.7% agar (conservation medium); about
70% of the cultures survived up to 18 mo at 25 ± 2°C. Successful regrowth of plants on micropropagation medium was obtained
by culturing nodal explants excised from 18-mo-old conserved plants. Some 96% of the plants survived the hardening treatment
and grew normally in a greenhouse. If 24 cultures are conserved on the conservation medium, it is possible to regenerate at
least 750 plants by using explants derived from 70% of the surviving shoots and culturing the same in micropropagation medium
for 4 mo. These plants may be used for planting or as a source of explants for the next conservation cycle. On the basis of
20 random amplified polymorphic DNA and 13 inter-simple sequence repeat primers analyses, no significant reproducible variation
was detected among the in vitro-conserved plants compared with the mother plants. 相似文献
9.
The induction of somatic embryogenesis from shoot apices and leaf explants of shoot cultures derived from 6- to 7-year-old
white oak (Quercus alba L.) trees is reported in this study. Embryogenic response was obtained in two out of the three genotypes evaluated with embryo
induction frequencies up to 50.7% for WOQ-1 and 3.4% for WOQ-5 genotypes. The embryogenic explants formed translucent nodular
structures and cotyledonary-stage somatic embryos, which developed from callus tissue, indicating an indirect embryogenesis
process. An efficient procedure was developed for WOQ-1 material on the basis of the most appropriate leaf developmental stage.
Growing leaves excised from two nodes below the shoot apex showed the highest embryogenic induction index. These leaves contain
cells in an undifferentiated state, as shown by the presence of precursor cells of stomata, absence of intercellular spaces
and low starch content in the mesophyll cells. Nodular structures and/or somatic embryos began to arise 7–8 weeks after culture
initiation, although most emerged after 9–12 weeks in culture. The sequence of application of media for somatic embryo induction
was optimized with a two-step procedure consisting of culturing the explants in medium supplemented with 21.48 μM NAA and
2.22 μM BA for 8 weeks and transfer of explants into plant growth regulator-free medium for another 12 weeks. Clonal embryogenic
lines were established and maintained by secondary embryogenesis. Embryo germination (30%) and plantlet conversion (16.6%)
were achieved after cold storage for 2 months. 相似文献
10.
Guohua Ma Jinfeng Lü Jaime A. Teixeira da Silva Xinhua Zhang Jietang Zhao 《Plant Cell, Tissue and Organ Culture》2011,104(2):157-162
Ochna integerrima is a medicinal and ornamental plant in Southeastern Asia. It has been listed as a rare and endangered species in China. Here
we studied the effects of plant growth regulators and their concentrations on the induction of somatic embryogenesis and shoot
organogenesis from leaf and shoot explants of O. integerrima for the first time. Cytokinins played a crucial role in somatic embryogenesis and shoot organogenesis. Among them, a higher
concentration of thidiazuron (10.0–15.0 μM TDZ) could induce both somatic embryogenesis and adventitious shoot formation whereas
low concentrations of TDZ (5.0 μM) could only induce adventitious shoots. However, 6-benzyladenine (BA at 5–15 μM) could only
induce adventitious shoots. Shoot explants induced more adventitious shoots and somatic embryos than leaf explants when cultured
on medium with the same concentration (5–15 μM) of TDZ or 15 μM BA. Medium containing 0.5 μM α-naphthaleneacetic acid and
8 μM indole-3-butyric acid and 0.1% activated charcoal could induce adventitious roots within 1 month. An efficient mass propagation
and regeneration system has been established. 相似文献
11.
This is the first report where shoot regeneration in strawberry cultivar Chandler has been achieved simultaneously through
both somatic embryogenesis and shoot bud formation. Direct somatic embryogenesis was observed in leaf discs which were cultured
on medium containing MS salts + B5 vitamins + 2% glucose + 18.16 μM thidiazuron (TDZ) and given both chilling and dark treatment for 2 wk at 4 ± 2°C followed
by incubation at 25 ± 2°C under 16-h photoperiod for third wk. After 3 wk, these explants were then subcultured on medium
containing MS salts + B5 vitamins + 2% glucose and incubated under 16-h photoperiod at 25 ± 2°C for further growth and development. Direct regeneration
via de novo shoot bud formation was observed in leaf disks which were given dark treatment and were cultured on medium containing MS
salts + B5 vitamins + 2% glucose supplemented with 9.08 μM TDZ. There was a synergistic effect of photoperiod, dark, and chilling treatments
on somatic embryogenesis, whereas chilling treatment had an inhibitory effect on shoot organogenesis. 相似文献
12.
A simple and efficient system was developed for rapid somatic embryogenesis from leaf explants of Merwilla plumbea, a traditional but threatened medicinal plant in South Africa. Friable embryogenic callus (FEC) was obtained from leaf explants
on embryogenic callus induction medium containing agar-solidified Murashige and Skoog (MS) salts and vitamins, 8.3 μM picloram,
2.3 μM thidiazuron (TDZ) and 20 μM glutamine. FEC was subsequently incubated in embryogenic callus proliferation medium containing
4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.1 μM picloram for 7 days before it was transferred to liquid somatic embryo
medium (SEML) containing MS medium supplemented with 0.4 μM picloram and 0.9 μM TDZ. In SEML supplemented with 150 mg L−1 haemoglobin, 5.4–35.6 somatic embryos per settled cell volume of 500 mg FEC were obtained. These embryos were at globular
to cotyledonary developmental stages. Embryo maturation, germination and plant formation rate was 94.4% following transfer
of SEs to half-strength MS medium supplemented with 1.4 μM gibberellic acid. Plantlets transferred into soil acclimatized
in the misthouse and established successfully in the greenhouse (100%). This is the first report on induction of Merwilla plumbea somatic embryogenesis. The protocol developed offers controlled vegetative propagation by alleviating extinction threats,
ensures germplasm conservation and provides a system for physiological, biochemical, molecular and cellular studies of embryo
development. 相似文献
13.
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
14.
Iyyakkannu Sivanesan Mi Young Lim Byoung Ryong Jeong 《Plant Cell, Tissue and Organ Culture》2011,107(2):365-369
A simple and efficient protocol was developed for somatic embryogenesis from leaf and petiole explants of Campanula punctata Lam. var. rubriflora Makino. Somatic embryos (SE) were obtained with greater frequency from petiole explants than from leaf explants when cultured
on Murashige and Skoog (MS) medium supplemented with 2.0 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg L−1 6-benzyladenine (BA). On this medium, a mean number of 19.5 and 31.2 SE were developed per leaf and petiole explants, respectively.
Embryos were induced both light and dark conditions but culturing the explants 2 weeks in the dark followed by 3 weeks under
light resulted in high frequency of embryo formation. Globular embryos germinated best on MS medium supplemented with 0.3%
(w/v) activated charcoal (AC) and 1.0 mg L−1 GA3. The germinated plantlets grew further on MS medium containing 0.3% AC. Plantlets were successfully acclimatized in the greenhouse
with 94% survival rate. This is the first report on induction of somatic embryogenesis in this genus and also has implications
for genetic transformation, and mass clonal propagation. 相似文献
15.
Plant regeneration through somatic embryogenesis was achieved using immature zygotic embryos (ZE) of Sorbus pohuashanensis as explants. Over 50% of immature ZEs from immature seed collected at 30 days after pollination produced direct somatic embryos
(SEs) on Murashige and Skoog (MS) medium supplemented with 0–0.44 μM 6-benzyladenine (BA) in combination with 5.73 μM naphthaleneacetic
acid (NAA) or with 0.91–2.26 μM 2,4-dichlorophenoxyacetic acid (2,4-D) alone. Fourteen to 23 SEs per explant were regenerated
on MS medium supplemented with BA 0.44 μM in combination with NAA 5.73 μM. SE formation decreased when sucrose concentrations
were higher than 40 g L−1. Repetitive embryogenesis occurred following culture on solid MS medium containing 12 μM abscisic acid, 75 g L−1 polyethylene glycol, and 20 g L−1 sucrose at 25 ± 1°C under a 16-h photoperiod with a light intensity of 40 μmol m−2 s−1. Over 40% of the mature SEs germinated on solid MS medium under light condition described previously. Up to 40% of the regenerated
plantlets were successfully acclimatized under greenhouse conditions. Plantlets derived from SEs grew vigorously with similar
morphology as those germinated from ZEs. Histological studies of explants at various developmental stages of somatic embryogenesis
revealed that SEs passed through globular, heart, torpedo, and mature stages. Similar to ZE suspensors, similar structures
of SE degenerated in later stages of embryo development. ZE and SE are a effective means of regenerating tissue culture plantlets
for S. pohuashanesis. 相似文献
16.
The morphogenetic potential of node, internode and leaf explants of Brahmi [Bacopa monniera (L.) Wettst.] was investigated to develop reliable protocols for shoot regeneration and somatic embryogenesis. The explants
were excised from shoots raised from axillary buds of nodal explants cultured on Murashige and Skoog (MS) basal medium. Presence
of 6-benzylaminopurine (BA) or kinetin influenced the degree of callus formation, from which a large number of shoot buds
regenerated. Leaf explants gave the largest number of shoot buds followed by node and internode explants. BA was superior
to kinetin; BA at 1.5 – 2.0 mg/l appeared to be optimum for inducing the maximum number of shoot buds. MS + 0.1 mg/l BA +
0.2 mg/l indole-3-acetic acid was the most suitable for shoot elongation. Elongated shoots were rooted on full- or half-strength
MS medium with or without 0.5 – 1.0 mg/l indole-3-butyric acid or 0.5 – 1.0 mg/l α-naphthaleneacetic acid. The rooted plants were successfully established in soil. Calli derived from nodal explants cultured
on MS medium containing 0.5 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), when subcultured on MS medium containing 0.1 or 0.5
mg/l BA or 0.2 mg/l 2,4-D + 0.1 or 0.5 mg/l kinetin, developed somatic embryos. The somatic embryos germinated either on the
same media or on MS basal medium, and the resulting plantlets were successfully transplanted to soil.
Received: 25 September 1996 / Revision received: 23 October 1997 / Accepted: 12 November 1997 相似文献
17.
Micropropagation has been achieved in a promising larvicidal asteraceous taxon Spilanthes acmella L. using seedling leaf explants. The explants were reared on a variety of growth regulators, namely 2,4-dichlorophenoxyacetic
acid, 1-naphthalene acetic acid, Indole-3-butyric acid, N6-benzyladenine, and kinetin either alone or in combination on Murashige and Skoog’s (MS) medium. The best green and compact
callus was obtained on 1 μM NAA and 10 μM benzyladenine (BA) in 15 d. The callus on subculture to the same but fresh medium
after every 30 d differentiated an average of 12.90 ± 0.32 shoot buds in 50% cultures. Elongation in shoot buds occurred only
if they were transferred to NAA lacking MS+BA medium. An average number of 4.22 ± 0.83 shoots and 15 ± 0.84 shoot buds per
explant were obtained in 70.3% cultures on MS + 10 μM BA in 30 d. One hundred percent excised shoots rooted in MS(1/2) + 0.1 μM
IBA within 2 wk. The plants were gradually hardened and established in soil where they flowered and set viable seeds. The
regenerated plants were morphologically similar to the field grown plants and showed 100% larvicidal activity against malaria
and filarial vectors. 相似文献
18.
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
19.
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
20.
Somatic embryos were obtained from immature zygotic embryos of Cedrela fissilis Well. (Meliaceae), after a culture period of 12 months, with regular subcultures every 6–8 weeks. Callus was developed on explants in 2 months
on Murashige and Skoog (MS) medium containing 2,4 dichlorophenoxyacetic acid (2,4-D) or picloram (PIC). When the calli were
transferred to fresh medium, embryogenic tissue appeared on MS + 45 μM 2,4-D, or 22.5 μM 2,4-D + 0.4 μM 6-benzyladenine (BA),
or 20.7 μM PIC after 6 months. Sub-culture of embryogenic tissue in MS medium supplemented with 4.5 μM 2,4-D resulted in the
differentiation into somatic embryos after further 4 months. Repeated secondary somatic embryogenesis was achieved by regular
subculture on this medium. Maturation and conversion of somatic embryos into plantlets was achieved on MS medium without plant
growth regulators and the conversion frequency was approximately 12.5 %. The plantlets were successfully acclimatized in pots
with soil. Histological studies showed that somatic embryos had no detectable connection with the mother explants and that
somatic embryos in advanced stages were bipolar with shoot and root apical meristems, they contained vascular system and showed
typical characteristics of a somatic dicotyledonous embryo. 相似文献