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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.
4.
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
5.
6.
Three pumpkin embryogenic lines were initiated on wounded zygotic embryos cultured on medium with or without 2,4-dichlorophenoxyacetic acid (2,4-D). Somatic embryo development was controlled by the availability of various compounds in the medium: presence/absence of 2,4-D, nitrogen sources. The highest rate of DNA methylation was in the early embryo stages, predominantly on MSC medium with 2,4-D and on auxin-free medium supplemented with 1.0 mM NH4Cl. DNA methylation was correlated with early embryo development in a manner that was not exclusively dependent on the presence/absence of exogenous auxin. DNA methylation decreased during embryo maturation on auxin-free MSC medium and on auxin-free MSC supplemented with 12.3 M 5-azacytidine (5-azaC). The embryogenic features of the pumpkin tissue were preserved, even after a 2-month treatment with 5-azaC.Abbreviations 5-azaC
5-Azacytidine
- CRED-RA
Coupled restriction enzyme digestion and random amplification
- 2,4-D
2,4-Dichlorophenoxyacetic acid
- DNMRT
Duncans new multiple range test
- IAA
Indole-3-acetic acid
- 5-mC
5-Methylcytosine 相似文献
7.
Summary The development of efficient tissue culture systems for cacao holds the potential to contribute to the improvement of this
tropical erop by providing a rapid and efficient vegetative propagation system for multiplication of elite genotypes. It may
also find application in facilitation of germplasm movement across quarantine borders, enhancement of germplasm conservation
via cryo-preservation, and development of genetic transformation systems. Somatic embryogenesis using floral tissue explants
was previously the only tissue culture procedure for regeneration of cacao. We report the development of a secondary embryogenesis
system utilizing primary somatic embryo cotyledon explants, which results in up to a 30-fold increase in somatic embryo production
compared to primary somatic embryogenesis. The influence of genotype on the efficiency of the system was evaluated. To understand
the cellular origins and developmental pathways operative in this system, we investigated the morphological changes occurring
over time using light and scanning electron microscopy. While primary embryos arise from clusters of cells forming embryonic
nodules, secondary embryos arise predominantly from the division of single cells, in a pathway reminiscent of zygotic embryogenesis.
These results have important significance to the application of tissue culture to cacao improvement programs. 相似文献
8.
Selection of international molecular standards for DNA fingerprinting of <Emphasis Type="Italic">Theobroma cacao</Emphasis> 总被引:1,自引:0,他引:1
Saunders JA Mischke S Leamy EA Hemeida AA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,110(1):41-47
A collaborative international program was initiated to identify and describe the genetic diversity of living germplasm collections of Theobroma cacao genotypes that are maintained in several international collections scattered throughout tropical cacao growing countries of the world. Simple sequence repeat (SSR) DNA analysis was identified as the most appropriate molecular tool for DNA fingerprinting these collections during an international forum representing academic, government and industry scientists in the cacao community. Twenty-five SSR primers, which had been previously described, were evaluated as potential candidates to define an efficient, standardized, molecular fingerprinting protocol for T. cacao accessions. These primers have been evaluated for reliability, widespread distribution across the cacao genome, number of alleles produced by the SSR primers in cacao and their ability to discriminate between cacao accessions. Approximately 690 cacao accessions were used to evaluate the utility of these SSR primers as international molecular standards, and a small number of test samples of T. cacao were sent to two other independent laboratories for verification. DNA fragments were selectively amplified by PCR, using the SSR primers labeled with fluorescent dyes, and separated by capillary electrophoresis. Based on this study, the 15 SSR primers that had the highest reproducibility and consistency within a common genotype, while allowing the differentiation of separate divergent genotypes, were selected as international molecular standards for DNA fingerprinting of T. cacao. 相似文献
9.
Patrícia Monah Cunha Bartos Hugo Teixeira Gomes Sueli Maria Gomes Sebastião Carvalho Vasconcelos Filho João Batista Teixeira Jonny Everson Scherwinski-Pereira 《Biologia》2018,73(12):1255-1265
The objective of this study was to characterize the histodifferentiation of somatic embryogenesis obtained from leaf explants of C. arabica. Therefore, we histologically analyzed the respective stages of the process: leaf segments at 0, 4, 7, 15 and 30 days of cultivation, Type 1 primary calli (primary calli with embryogenic competence) and 2 (primary calli with no embryogenic competence), embryogenic calli, globular, torpedo and cotyledonary embryos, and mature zygotic embryos. Callus formation occurred after seven days of culture, with successive divisions of procambium cell. In this cultivation phase, it was found that Type 1 primary calli are basically formed by parenchymal cells with reduced intercellular spacing, whereas Type 2 primary calli are predominantly composed of parenchymal cells with ample intercellular spaces and embryogenic calli composed entirely of meristematic cells. After 330 days, it was evident from the differentiation of somatic embryogenesis that there was formation of globular somatic embryos, consisting of a characteristic protoderm surrounding the fundamental meristem. With the maturation of these propagules after 360 days, torpedo-stage somatic embryos arose, in which tissue polarization and early differentiation of procambial strands were verified. After 390 days, cotyledonary somatic embryos were obtained, where the onset of vessel elements differentiation was verified, a characteristic also observed in mature zygotic embryos. We concluded that somatic embryogenesis obtained from C. arabica leaves initiates from procambium cell divisions that, in the course of cultivation, produce mature somatic embryos suitable for regenerating whole plants. 相似文献
10.
Ananya Paul Kalyan Mitter Sarmistha Sen Raychaudhuri 《Plant Cell, Tissue and Organ Culture》2009,97(3):303-311
The effects of exogenous polyamines (PAs) on enhancement of somatic embryogenic calli was investigated in Momordica
charantia L. in vitro. Induction of somatic embryogenesis (SE) in leaf explants of M. charantia after 21 days of culture in Murashige and Skoog (MS) medium was determined using scanning electron microscopy. During induction
of SE there were high titers of Putrescine (Put) as compared to Spermidine (Spd) and Spermine (Spm), a prerequisite for cell
division. Addition of PAs to the embryogenic media resulted in an increase in fresh weights and number of somatic embryos
of 21-day old embryogenic calli. Put at a concentration of 1 mM showed maximum increase in fresh weights of embryogenic calli
(5 fold) and number of somatic embryos produced per 0.2 g of callus (2.5 fold). Moreover addition of PAs to the embryogenic
media resulted in lowering of endogenous free PA level of 21-day old embryogenic calli. Thus, when the media was supplemented
with exogenous PAs a positive correlation was found to exist between Somatic Embryogenesis enhancement and decrease in endogenous
free PA levels. 相似文献
11.
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
12.
Protoplasts isolated from wild cotton Gossypium davidsonii were cultured in KM8P medium supplemented with different phytohormones. The most effective combination was 0.45 μM 2,4-dichlorophenoxyacetic acid,
2.68 μM α-naphthaleneacetic acid and 0.93 μM kinetin and the division percentage at the 8th day was 30.78 ± 3.04 %. The density of protoplasts at 2–10 × 105 cm−3 was suitable for protoplast division and calli formation, with a division percentage of 32.21 ± 3.64 % and a plating efficiency
of 9.12 ± 2.61 % at the 40th day. The optimal osmotic potential was achieved using 0.5 M glucose or 0.1 M glucose plus 0.5 M mannitol. Protoplasts were
cultured in three ways, a double-layer culture system, with liquid over solid medium was proved to be the best way. Embryo
induction was further increased by addition of 0.14 μM gibberellic acid. 相似文献
13.
K. P. Martin A. Shahanaz Beegum C.-L. Zhang A. Slater P. V. Madhusoodanan 《Biologia Plantarum》2007,51(4):769-772
In vitro propagation of an anticancerous drug synthesizing plant, Ophiorrhiza prostrata D. Don, was established through indirect somatic embryogenesis. Friable embryogenic calluses were initiated from O. prostrata leaf and internode explants on Murashige and Skoog (MS) media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) either
alone or in combination with N6-benzyladenine (BA) or kinetin (KIN). Somatic embryos were developed after subculture of the friable calluses onto half strength
MS media containing 0.45 or 2.26 μM 2,4-D alone or in combination with BA or KIN. Medium supplemented with 2.26 μM 2,4-D and
2.22 μM BA was optimal, supporting the production of a mean of 5.8 globular embryos. Subculture of globular embryo-bearing
calluses on half strength MS medium without growth regulators produced the highest embryo frequency, and the majority of them
developing to early torpedo stage. Somatic embryos underwent maturation and converted to plantlets at high frequency (90 %)
on half strength MS medium supplemented with 0.44 μM BA. Somatic embryo-derived plantlets with well-developed roots were established
in field conditions with a 90 % survival rate. 相似文献
14.
15.
I. N. Tretyakova M. E. Park A. S. Ivanitskaya N. V. Oreshkova 《Russian Journal of Plant Physiology》2016,63(6):800-810
Morphogenesis and maturation of somatic embryos, ploidy, and genotyping of cell lines (CL) of embryogenic cultures of Larix sibirica Ledeb. in vitro were investigated during 2–6 years. It was revealed that from 2000 to 11103 globular somatic embryos were formed in proliferating CL. However, the ability of somatic embryos to the maturation and germination decreased. Cytogenetic study of embryonal-suspensor masses (ESM) of Larix sibirica demonstrated that cells of long-term cultivated cultures remained diploid. According to microsatellite analysis, proliferating CL of Siberian larch were characterized by weak allelic variability, and cell line 6 and cloned seedlings of this line were genetically stable and corresponded to the donor tree. Embryogenic cell lines composed the collection bank, which will be successfully used for plantation forest growing. 相似文献
16.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献
17.
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
18.
In the present study, in vitro regeneration system for a recalcitrant woody tree legume, Leucaena leucocephala (cvs. K-8, K-29, K-68 and K-850) from mature tree derived nodal explants as well as seedling derived cotyledonary node explants
was developed. Best shoot initiation and elongation was found on full-strength Murashige and Skoog (MS) medium supplemented
with 3 % (m/v) sucrose, 100 mg dm−3 myoinositol, 100 mg dm−3 glutamine, 20.9 μM N
6-benzylamino-purine (BAP) and 5.37 μM 1-naphthalene acetic acid (NAA). Rooting was induced in half-strength MS medium containing
2 % (m/v) sucrose, 100 mg dm−3 myoinositol, 14.76 μM indole-3-butyric acid (IBA) and 0.23 μM kinetin. The cultivar K-29 gave the best response under in vitro conditions. Rooted plantlets were subjected to hardening and successfully transferred to greenhouse. Further, somatic embryogenesis
from nodal explants of cv. K-29 via an intermittent callus phase was also established. Pronounced callusing was observed on full-strength MS medium containing
3 % (m/v) sucrose, 100 mg dm−3 myoinositol, 40.28 μM NAA and 12.24 μM BAP. These calli were transferred to induction medium and maximum number of globular
shaped somatic embryos was achieved in full-strength MS medium fortified with 3 % (m/v) sucrose, 100 mg dm−3 myoinositol, 15.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D), 5.0 μM BAP and 1.0 mM proline. Moreover, an increase in endogenous
proline content up to 28th day of culture in induction medium was observed. These globular shaped somatic embryos matured in full-strength MS medium
with 3 % (m/v) sucrose, 100 mg dm−3 myoinositol, 10.0 μM BAP, 2.5 to 5.0 μM IBA and 0.5 mM spermidine. 相似文献
19.
Rangan Parimalan Akshatha Venugopalan Parvatam Giridhar G. A. Ravishankar 《Plant Cell, Tissue and Organ Culture》2011,105(3):317-328
Establishment, maintenance, regeneration, and transformation of somatic embryos by both direct and indirect means (callus-mediated)
was achieved for Bixa orellana, a tropical plant whose seeds produce commercially edible ‘annatto pigment,’ which mainly constitutes an apocarotenoid called
bixin. Callus-mediated methodology was found to be efficient in producing a greater number of embryos in a short time. The
maximum of 28 somatic embryos were produced in 16–18 weeks when immature zygotic embryonic stalks were inoculated onto Murashige
and Skoog (MS) medium containing B5 vitamins supplemented with 0.44 μM benzyladenine (BA), 0.054 μM α-naphthaleneacetic acid
(NAA), 2.89 μM gibberellic acid (GA3), 0.02 μM triiodobenzoic acid (TIBA), and 0.011 μM triacontanol (TRIA). Callus initiation from hypocotyl explants was obtained
on MS medium supplemented with 1.07–2.14 μM NAA and 10.2 μM BA. In 3 months, somatic embryos were produced when callus was
inoculated onto MS medium supplemented with 4.44 μM BA, 40 μM AgNO3, and 0.011 μM TRIA. Somatic embryos were efficiently regenerated on MS basal solid and liquid media supplemented with 0.44–4.4 μM
BA, 0.54–2.69 μM NAA, 4.92 μM 2iP, 2.1 μM calcium d-pantothenate, 0.21 μM biotin, 227.7 μM cysteine HCl monohydrate, and 108.6 μM adenine sulfate. Agrobacterium tumefaciens GV 3101 harboring pCAMBIA 1305.2 binary vector-mediated stable transformation of somatic embryos exhibited a transformation
frequency of 2.56%. As somatic embryogenesis in any perennial system is useful in terms of both commercial and scientific
nature, this somatic embryo-based transformation protocol for the commercially important dye-yielding tropical plant B. orellana is useful for its improvement through genetic engineering. 相似文献
20.
Ethylene biosynthesis during different phases of somatic embryogenesis in Medicago sativa L. cv. Rangelander using two regeneration protocols, RPI and RPII, was studied. The highest ethylene production was detected
during callus growth on induction medium in both regeneration protocols. Significantly less ethylene was produced by embryogenic
suspension than by callus (RPII). Developing embryos synthesized higher amounts of ethylene than mature embryos. Production
of ethylene was strongly limited by the availability of 1-aminocyclopropane-1-carboxylic acid and also by ACC-oxidase activity.
However, removal of ethylene from culture vessels’ atmosphere using KMnO4 or HgClO4 had no significant effect on callus growth, somatic embryo induction and development. Reducing of ethylene biosynthesis by
aminoethoxyvinylglycine substantially decreased somatic embryo production and adversely affected their development, indicating
ethylene requirement during proliferation and differentiation but not induction. 相似文献