共查询到20条相似文献,搜索用时 15 毫秒
1.
Siela N. Maximova Ann Young Sharon Pishak Mark J. Guiltinan 《In vitro cellular & developmental biology. Plant》2008,44(6):487-493
Somatic embryogenesis is an in vitro clonal propagation method with potential to contribute to the improvement of cacao varieties. Before using this technology
for commercial production, it is essential that somatic embryogenesis-derived plants be tested in field conditions. Therefore,
we established a field test at Union Vale Estate, Saint Lucia. Thirty- to 50-yr-old trees were selected for clonal propagation
as potentially high yielding based on local farmers observations. Clonal plants were propagated in vitro from immature flowers by embryogenesis and micropropagation. Multiple plants from nine genotypes were acclimated to greenhouse
conditions then returned to Saint Lucia and planted in a field. Orthotropic rooted cuttings and locally propagated open pollinated
seedlings were also planted for a total of 214 trees. Growth data were collected every 4–6 mo. including: stem diameter, stem
height, length of the longest jorquette branch, number of jorquette branches, and dates of first flowering and fruiting. At
4.5 yr after planting in the field there were no major differences in all growth parameters among the propagation methods
evaluated with exception of the orthotropic rooted cuttings. Trees grown from seeds were slightly taller then trees propagated
by the other methods. Trees propagated as orthotropic rooted cuttings exhibited smaller average stem diameters, shorter stem
heights to the jorquette, and shorter jorquette branches. We concluded that somatic embryo-derived plants demonstrated normal
phenotypes in field conditions and have growth parameters similar to plants propagated by traditional methods. 相似文献
2.
Summary A micropropagation protocol was developed using cacao somatic embryo-derived plant as a source for nodal and apical stem explants,
and apical microcuttings. Microcuttings were efficiently rooted and developed into plantlets. Axillary meristems within the
remaining decapitated plantlets subsequently developed and were used for production of additional microcuttings, with an average
2.4 growing shoots per decapitated stem. The remaining plantelts were maintained as microcutting stock plants. When nodal
stem explants were cultured on thidiazuron medium, axillary buds proliferated and developed into shoots, which were excised
and rooted. However, the efficiency of this method is lower than rooting of apical microcuttings harvested directly from stock
plants. During root induction, short treatment with indole-3-butyric acid (IBA) increased the total percentage of rooted microcuttings
up to 89%. Longer exposures to IBA increased the average number of roots per microcutting (from 1.7 to 5.2). Plant acclimatization
after rooting was achieved with an average success of 87%. During several months of growth in the greenhouse, the micropropagated
plants developed functional taproots. Currently, cocoa plants produced by this micropropagation method have been successfully
acclimated to field conditions in Ivory Coast, Ghana, and Saint Lucia. 相似文献
3.
Summary High-frequency somatic embryogenesis and plant regeneration was achieved on callus derived from leaf (petiole and lamina)
and internode explants of Centella asiatica L. Growth regulators significantly influenced the frequency of somatic embryogenesis and plant regeneration. Calluses developed
on Murashige and Skoog (MS) medium fortified with 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D) or 5.37 μM α-naphthaleneacetic acid (NAA), both with 2.32 μM kinetin (Kn), were superior for somatic embryogenesis. Callus developed on NAA and Kn-supplemented medium favored induction
and maturation of embryos earlier compared to that on 2,4-D and Kn. Embryogenic callus transferred from NAA and Kn-supplemented
medium to suspension cultures of half-strength MS medium with NAA (2.69 μM) and Kn (1.16 μM) developed a mean of 204.3 somatic embryos per 100 mg of callus. Embryogenic callus transferred from 2,4-D and Kn subsequently
to suspension cultures of half-strength MS medium with 2,4-D (0.45 μM) and Kn (1.16 μM) developed a mean of 303.1 embryos per 100 mg of callus. Eighty-eight percent of the embryos underwent maturation and conversion
to plantlets upon transfer to half-strength MS semisolid medium having 0.054 μM NAA with either 0.044 μM BA or 0.046 μM Kn. Embryo-derived plantlets established in field conditions displayed morphological characters identical to those of the
parent plant. 相似文献
4.
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
5.
Summary A highly reproducible method for regeneration of Coffea arabica and C. canephora plants via direct somatic embryogenesis from cultured leaf and stem segments of regenerated plants was developed. Embryogenesis
was influenced by the presence of triacontanol (TRIA) in the medium. TRIA incorporated at 4.55 and 11.38 μM in half-strength MS basal medium containing 1.1 μM 6-benzyladenine (BA) and 2.28 μM indole-3-acetic acid (IAA) induced direct somatic embryogenesis in both species. A maximum of 260±31.8 and 59.2±12.8 somatic
embryos per culture were induced from in vitro leaf explants of C. arabica and C. canephora, respectively. TRIA also induced embryo formation from in vitro stem segment callus tissues along with multiplication of primary embryos into secondary embryos. By using TRIA, it was possible
to obtain somatic embryogenesis in C. arabica and C. canephora. 相似文献
6.
A new method was established for somatic embryogenesis and plant regeneration from callus cultures of Dioscorea zingiberensis C.H. Wright. Primary callus was induced by culturing stems, leaves and petioles on Murashige and Skoog (MS) medium supplemented with 0.5–2.0 mg l–1 N6-benzyladenine (BA) and 0–2.0 mg l–1 -naphthaleneacetic acid (NAA) or 2,4-dichlorophenoxyacetic acid (2,4-D) for 1 month. The highest frequency (87%) of callus formation was achieved from stem explants treated with 0.5 mg l–1 BA and 2.0 mg l–1 2,4-D. Somatic embryos were obtained by subculturing embryogenic calli derived from stem explants on MS medium supplemented with 2.0–4.0 mg l–1 BA and 0–0.4 mg l–1 NAA or 2,4-D for 3 weeks. The optimum combination of 4.0 mg l–1 BA and 0.2 mg l–1 NAA promoted embryo formation on one-third of the calli. After a further month of subculture on the same medium, mature embryos were transferred to MS medium supplemented with 0–4.0 mg l–1 BA, NAA or indole-3-butyric acid (IBA) for further development of plantlets and tuber formation. Plant growth regulators had a negative effect on the development of mature embryos. 相似文献
7.
8.
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
9.
Summary
Kalopanax pictus (Thunb.) Nakai is a tall tree, and its wood has been used in making furniture, while its stem bark is used for medicinal
purposes. Here, we report on the micropropagation of Kalopanax pictus via somatic embryogenesis. Embryogenic callus was induced from immature zygotic embryos. The frequency embryogenic callus
induction is influenced by days of seed harvest. Callus formation was primarily observed along the radicle tips of zygotic
embryos incubated on Murashige and Skoog (MS) medium with 4.4 μM 2,4-dichlorophenoxyacctic acid (2,4-D). Somatic embryogenesis was observed following transfer of embryogenic callus to MS
medium lacking 2,4-D. Somatic embryos at the cotyledonary stage were obtained after 6 wk following culture. Frequency of conversion
of somatic embryos into plantlets was low (35%) on a hormone-free MS basal medium, but it increased to 61% when the medium
was supplemented with 0.05% charcoal. Gibberellic acid (GA3) treatment markedly enhanced the germination frequency of embryos up to 83%. All plantlets obtained showed 98% survival on
moist peat soil (TKS2) artificial soil matrix. About 30 000 Kalopanax pictus plants were propagated via somatic embryogenesis and grown to 3-yr-old plants. These results indicate that production of
woody medicinal Kalopanax pictus plantlets through somatic embryogenesis can be practically applicable for propagation. 相似文献
10.
A reproducible protocol for somatic embryogenesis (SE) induction in Eucalyptus globulus from mature zygotic embryos is available since 2002. However, for the use of SE in tree breeding programs, the frequency of SE initiation needs to be improved and controlled, and this was investigated in 13 open-pollinated (OP) families over three consecutive years. A diallel mating design with five parent trees was used to study genetic control of SE induction. Results showed that SE induction varies across E. globulus families and over the years of seed production tested. Somatic embryogenesis was initiated on explants from 84% of the OP families tested in 2002 and 100% of the families tested in 2003 and 2004. The year 2003 gave best results for percentage of induction and total number of somatic embryos produced. Results concerning genetic control showed that SE induction is under the control of additive genetic effects, as 22.0% of variation in SE initiation was due to general combining ability (GCA) effect, whereas 6.4% was due to maternal effects. Neither specific combining ability (SCA) nor reciprocal effects were significant. 相似文献
11.
David N. Kuhn Antonio Figueira Uilson Lopes Juan Carlos Motamayor Alan W. Meerow Kathleen Cariaga Barbie Freeman Donald S. LivingstoneIII Raymond J. Schnell 《Tree Genetics & Genomes》2010,6(5):783-792
The seeds of Theobroma cacao (cacao) are the source of cocoa, the raw material for the multi-billion dollar chocolate industry. Cacao’s two most important
traits are its unique seed storage triglyceride (cocoa butter) and the flavor of its fermented beans (chocolate). The genome
of T. cacao is being sequenced, and to expand the utility of the genome sequence to the improvement of cacao, we are evaluating Theobroma grandiflorum, the closest economically important species of Theobroma for its potential use in a comparative genomic study. T. grandiflorum differs from cacao in important agronomic traits such as flavor of the fermented beans, disease resistance to witches’ broom
and abscission of mature fruits. By comparing genomic sequences and analyzing viable inter-specific hybrids, we hope to identify
the key genes that regulate cacao’s most important traits. We have investigated the utility in T. grandiflorum of three types of markers (microsatellite markers, single-strand conformational polymorphism markers and single nucleotide
polymorphism (SNP) markers) developed in cacao. Through sequencing of amplicons of 12 diverse individuals of both cacao and
T. grandiflorum, we have identified new intra- and inter-specific SNPs. Two markers which had no overlap of alleles between the species were
used to genotype putative inter-specific hybrid seedlings. Sequence conservation was significant and species-specific differences
numerous enough to suggest that comparative genomics of T. grandiflorum and T. cacao will be useful in elucidating the genetic differences that lead to a variety of important agronomic trait differences. 相似文献
12.
The mechanisms that reduce the viability of plant somatic embryos following cryopreservation are not known. The objective
of the present study was to evaluate the sensitivity of cocoa (Theobroma cacao L.) somatic embryos at different stages of an encapsulation–dehydration protocol using stress-related volatile hydrocarbons
as markers of injury and recovery. The plant stress hormone ethylene and volatile hydrocarbons derived from hydroxyl radicals
(methane) and lipid peroxidation (ethane) were determined using gas chromatography headspace analysis. Ethylene and methane
were the only volatiles detected, with both being produced after each step of the cryogenic protocol. Ethylene production
was significantly reduced following exposure to liquid nitrogen, but then increased in parallel with embryo recovery. In contrast,
the production of methane was cyclic during recovery, with the first cycle occurring earlier for embryos recovered from liquid
nitrogen and desiccation than those recovered from earlier steps in the protocol. These results suggest that loss of somatic
embryo viability during cryopreservation may be related to the oxidative status of the tissue, and its capacity to produce
ethylene. This study has demonstrated that headspace volatile analysis provides a robust non-destructive analytical approach
for assessing the survival and recovery of plant somatic embryos following cryopreservation. 相似文献
13.
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
14.
15.
Liliana Alexandra Pila Quinga Hugo Pacheco de Freitas Fraga Leila do Nascimento Vieira Miguel Pedro Guerra 《Plant Cell, Tissue and Organ Culture》2017,131(2):295-305
In Theobroma cacao L., declined embryogenic potential was observed in regenerated somatic embryos from long-term secondary somatic embryogenesis (SE). In order to explore the relationship between DNA methylation and the long-term secondary SE, the embryogenic potential and global DNA methylation levels in young (12 months-old), aged (36 months-old) and extra somatic embryogenesis (39 months-old) subjected to different 5-Azacytidine (5-azaC) treatments were comparatively assessed. Global DNA methylation levels increased in aged somatic embryos with long-term in vitro culture, but 5-azaC-supplemented treatments resulted in unaltered levels. In addition, DNA methylation pattern during SE was not affected by 5-azaC. DNA methylation increased during SE expression. Interestingly, the extra SE induction showed that aged somatic embryos can recovery the embryogenic potential in treatment supplemented with 5-azaC at specific concentration. The outcome of this study suggested that the long-term SE in cacao induced the decline on embryogenic potential, which can be reversible trough 5-azaC supplementation. Besides, increased DNA methylation levels might be a response to the stress conditions that plant cells were exposed to during SE. 相似文献
16.
Summary A protocol was developed for high frequency somatic embryogenesis and plant regeneration from cotyledon and hypocotyl explants
of Eruca sativa. Explants grown on Murashige and Skoog (MS) medium supplemented with 4.52 μM 2,4-D formed embryogenic callus after 4 wk of culture. Secondary somatic embryos were also produced from primary somatic
embryos on MS medium containing 0.56 μM 2,4-D. Somatic embryos developed into mature embryos on MS medium in the presence of 45 gl−1 polyethylene glycol. After desiccation, somatic embryos developed into plantlets by culturing the mature somatic embryos
on 1/2 x MS medium containing 0.24 μM indole-3-butyric acid. 相似文献
17.
Ranjana Bhattacharjee Maria Kolesnikova-Allen Peter Aikpokpodion Sunday Taiwo Ivan Ingelbrecht 《Plant Molecular Biology Reporter》2004,22(4):435-436
DNA extraction is a time-consuming and expensive component of molecular marker analysis, constituting about 30–60% of the
total time required for sample processing. Furthermore, the procedure for extracting high-quality DNA from tree species such
as cocoa differs from extraction protocols suitable for other crop plants. This is accompanied by problems in collecting leaf
tissues from field-grown cocoa trees, where storage facilities are not available and where transporting samples to laboratory
for immediate refrigeration is usually impossible. We preserved cocoa leaf tissues in the field in an NaCl-CTAB-azide solution
(as described in Rogstad, 1992), which did not require immediate refrigeration. This method also allowed preservation of leaf
tissues for a few days during transportation and protected leaf tissues from bacterial and fungal attacks. Once transported
to the laboratory, the samples were stored at 4°C for almost 1 y. To isolate good-quality DNA from stored leaf tissues, a
rapid semiautomated and relatively high-throughput protocol was established. The procedure followed a modified CTAB/β-mercaptoethanol
method of DNA extraction in a 96-well plate, and an automated system (i.e., GenoGrinder 2000) was used to grind the leaf tissues.
The quality of DNA was not affected by long storage, and the quantity obtained per sample was adequate for about 1000 PCR
reactions. Thus, this method allowed isolation of about 200 samples per day at a cost of $0.60 per sample and is a relatively
high-throughput, low-cost extraction compared with conventional methods that use manual grinding and/or expensive kits. 相似文献
18.
Summary Axillary and terminal buds from suckers of Ananas comosus cv. Phuket were established on Murashige and Tucker-based (MT) medium with 2.0 mgl−1 (9.8 μM) indolebutyric acid, 2.0 mgl−1 (10.74 μM) naphthaleneacetic acid, and 2.0 mgl−1 (9.29 μM) kinetin, followed by multiplication on Murashige and Skoog-based (MS) medium containing 2.0 mgl−1 (8.87 μM) benzyladenine (BA) to provide a continuous supply of axenic shoots. Leaves, excised from such cultured shoots, produced
adventitious shoots from their bases when these explants were cultured on MS medium containing 0.5 mgl−1 (2.26 μM) 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.0 mgl−1 (8.87 μM) BA. Embryogenic callus was produced when leaf explants were cultured on MS medium with 3.0 mgl−1 (12.42 μM) 4-amino-3,5,6-trichloropicolinic acid (picloram). Somatic embryos developed into shoots following transfer of embryogenic
tissues to MS medium with 1.0 mgl−1 (4.44 μM) BA. Cell suspensions, initiated by transfer of embryogenic callus to liquid MS medium with 1.0 mgl−1 (4.14 μM) picloram or 1.0 mgl−1 (4.52 μM) 2,4-D, also regenerated shoots by somatic embryogenesis, on transfer of cells to semisolid MS medium with 1.0 mgl−1 (4.44 μM) BA. All regenerated shoots rooted on growth regulator-free MS medium, prior to ex vitro acclimation and transfer to the glasshouse. These studies provide a baseline for propagation, conservation, and genetic manipulation
of elite pineapple germplasms. 相似文献
19.
A protocol was developed for rapid and efficient production of transgenic celery plants via somatic embryo regeneration from
Agrobacterium tumefaciens- inoculated leaf sections, cotyledons and hypocotyls. These explants were excised from in vitro seedlings of the cvs. XP166
and XP85 and inoculated with A. tumefaciens strain EHA105 containing the binary vector pBISN1. PBISN1 has the neomycin phosphotransferase gene (nptII) and an intron interrupted β-glucuronidase (GUS) reporter gene (gusA). Co-cultivation was carried out for 4 d in the dark on callus induction medium (CIM): Gamborg B5 + 2.79 μM kinetin + 2.26 μM
2,4-dichlorophenoxyacetic acid (2,4-D) supplemented with 100 μM acetosyringone. Embryogenic calluses resistant to kanamycin
(Km) were then recovered on CIM + 25 mg l−1 Km + 250 mg l−1 timentin after 12 weeks. Subsequently, a large number of Km-resistant and GUS-positive transformants, tens to hundreds per
explant were regenerated via somatic embryogenesis on Gamborg B5 + 4.92 μM 6 (γ,γ-dimethylallylamino)-purine (2iP) + 1.93 μM
α-naphthaleneacetic acid (NAA) + 25 mg l−1 Km + 250 mg l−1 timentin after 8 weeks. Using this protocol, the transformation frequency was 5.0% and 5.0% for leaf sections, 17.8% and
18.3% for cotyledons, and 15.9% and 16.7% for hypocotyl explants of cvs. XP85 and XP166, respectively. Stable integration
of the model transgenes with 1–3 copy numbers was confirmed in all ten randomly selected transgenic events by Southern blot
analysis of gusA. Progeny analysis by histochemical GUS assay showed stable Mendelian inheritance of the transgenes. Thus, A. tumefaciens-mediated transformation of cotyledons or hypocotyls provides an effective and reproducible protocol for large-scale production
of transgenic celery plants. 相似文献
20.
M. Capuana G. Petrini A. Di Marco R. Giannini 《In vitro cellular & developmental biology. Plant》2007,43(2):101-110
This is the first report on somatic embryogenesis in common ash (Fraxinus excelsior L.). Experiments on somatic embryogenesis induction were carried out on zygotic embryos at different phases of development
and maturation. The embryo axes were isolated and cultured on media containing different plant growth regulators (PGRs). Embryogenic
tissues were obtained from embryos collected at an incomplete maturation phase and cultured on a modified Murashige and Skoog
medium containing 8.8 μM 2,4-dichlorophenoxyacetic acid and 4.4 μM benzyl-adenine (BA). Embryos isolated from seeds at an
advanced stage of maturation showed only organogenetic phenomena. Embryogenic tissues were successfully subcultured and multiplied
on medium containing a reduced concentration of PGRs. After their isolation, somatic embryos were induced to develop and mature
by transfer to PGR-free medium and subsequent culture on medium containing 0.1 μM BA. Somatic embryos developed completely
and also germinated spontaneously. Embryo germination and conversion were significantly improved when subjected to a period
of storage at 4°C and transplant onto woody plant medium. Plantlets were successfully transferred to soil and acclimatized
in a “misted” greenhouse. 相似文献