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1.
The evolution of terrestrial plant life was made possible by the establishment of a root system, which enabled plants to migrate from aquatic to terrestrial habitats. During evolution, root organization has gradually progressed from a very simple to a highly hierarchical architecture. Roots are initiated during embryogenesis and branch afterward through lateral root formation. Additionally, adventitious roots can be formed post‐embryonically from aerial organs. Induction of adventitious roots (ARs) forms the basis of the vegetative propagation via cuttings in horticulture, agriculture and forestry. This method, together with somatic embryogenesis, is routinely used to clonally multiply conifers. In addition to being utilized as propagation techniques, adventitious rooting and somatic embryogenesis have emerged as versatile models to study cellular and molecular mechanisms of embryo formation and organogenesis of coniferous species. Both formation of the embryonic root and the AR primordia require the establishment of auxin gradients within cells that coordinate the developmental response. These processes also share key elements of the genetic regulatory networks that, e.g. are triggering cell fate. This minireview gives an overview of the molecular control mechanisms associated with root development in conifers, from initiation in the embryo to post‐embryonic formation in cuttings. 相似文献
2.
Leaf tissues of 38 genotypes, derived from four accessions, of the hexaploid species Helianthus tuberosus (2n=6x=102) responded to growth regulators (BA, NAA) chiefly by forming callus, while aventitious organogenesis or somatic
embryogenesis were induced occasionally. A remarkable regeneration frequency (about 30 %) was achieved only from leaves of
genotype HTPI-15. Explants of many regenerated plants of HTPI-15 subjected to a second culture cycle in vitro displayed a high morphogenetic potential (regeneration frequency > 90 %). White globular structures were initiated on the
adaxial surface of these leaves without a callus phase. Somatic embryogenesis was asynchronous and embryoids, of different
developmental stage, were simultaneously detected on each explant. Although many embryos developed single or malformed cotyledons
or germinated precocciously, without the differentiation of a complete root system, phenotypically normal plants were regenerated
after rooting on regulator-free half-strength MS medium.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
The effect of different genotypes of the ectomycorrhizal fungus Hebeloma cylindrosporum on in vitro rooting of micropropagated cuttings of Prunus avium and P. cerasus was studied in an attempt to determine whether ectomycorrhizal fungi could enhance in vitro adventitious root formation in
plants which form arbuscular endomycorrhizas. The rooting percentage of P. avium cuttings was approximately 16% in the absence of hormonal treatment; it increased up to 30% in the presence of 5.7 μM IAA
which was the most favourable auxin concentration. The rooting percentage of cuttings cultivated in the absence of IAA was
enhanced by all the studied strains of H. cylindrosporum. It ranged from 50 to 60% with the IAA-overproducing mutant D 111 or the wild-type dikaryon D1, to 100% in the presence of
the mutants 331 or D 117. The cuttings of P. cerasus showed a higher rooting ability than those of P. avium since approximately 40% of them were able to root in the absence of hormonal treatment. Except for the mutant D117, their
rooting percentage was not significantly improved by H. cylindrosporum. Fungal inoculation also affected the survival of cuttings at acclimatization: 50% of the uninoculated P. avium cuttings survived whereas the survival percentage of inoculated cuttings ranged from 30 to 100% depending on the fungal genotype.
With P. cerasus, the percentage of survival of uninoculated cuttings ranged from 85 to 100% and fungi either did not significantly improve
it or lowered it. At acclimatization fungal hyphae could be observed in close contact with adventitious roots, but they did
not establish mycorrhizal association. The shoot height of P. avium plantlets obtained from inoculated cuttings was not significantly different from that of plantlets originating from uninoculated
ones. By contrast, fungal inoculation generally depressed the growth of acclimatized P. cerasus plantlets. The possibility of using ectomycorrhizal fungi as a tool to enhance rooting of micropropagated cuttings of plants
which do not form ectomycorrhizas is discussed.
Received: 25 November 1996 / Accepted: 2 June 1997 相似文献
4.
Synthetic seed technology requires the inexpensive production of large numbers of high-quality somatic embryos. Proliferating embryogenic cultures from conifers consist of immature embryos, which undergo synchronous maturation in the presence of abscisic acid and elevated osmoticum. Improvements in conifer somatic embryo quality have been achieved by identifying the conditions in vitro that resemble the conditions during in ovulo development of zygotic embryos. One normal aspect of zygotic embryo development for conifers is maturation drying, which allows seeds to be stored and promotes normal germination. Conditions of culture are described that yield mature conifer somatic embryos that possess normal storage proteins and fatty acids and which survive either partial drying, or full drying to moisture contents similar to those achieved by mature dehydrated zygotic embryos. Large numbers of quiescent somatic embryos can be produced throughout the year and stored for germination in the spring, which simplifies production and provides plants of uniform size. This review focuses on recent advances in conifer somatic embryogenesis and synthetic seed technology, particularly in areas of embryo development, maturation drying, encapsulation and germination. Comparisons of conifer embryogeny are made with other gymnosperms and angiosperms.Abbreviations ABA
abscisic acid
- LEA
late embryogenesis abundant
- PEG
polyethylene glycol
- PGR
plant growth regulator
- RH
relative humidity
- TAG
triacylglycerol 相似文献
5.
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
6.
Sood Anil Ahuja P.S. Sharma Madhu Sharma O.P. Godbole Savita 《Plant Cell, Tissue and Organ Culture》2002,71(1):55-63
Seedling raised elites of Dendrocalamus hamiltoniiNees et Arn. Ex Munro were chosen as the source of nodal explants from precocious branches. While axillary bud break was accomplished in hormone free 1/2MS medium containing sucrose (3%, w/v), BA supplementation was required for shoot proliferation. A variety of hormonal combinations induced rooting in clumps of shoots. Somatic embryogenesis was also obtained in callus cultures raised in 2,4-D supplemented MS medium and plantlets derived from somatic embryos were hardened for field transfer. Comparative growth performances of plants raised from nodal cuttings of field-grown plants, those from single node cuttings of precocious branches and from somatic embryos indicated that growth performance of the tissue culture raised plants was relatively better than those from nodal cuttings. Improved protocols for efficient micropropagation are visualized to provide an impetus to raising of bamboo nurseries of elite genotypes in bamboo growing areas of western Himalayas. 相似文献
7.
Summary This is the first report of simultaneous organogenesis and somatic embryogenesis in Arnebia euchroma, a highly valued, critically endangered medicinal plant of the Himalaya. Root-derived callus showed only rhizogenesis, whereas
leaf-derived callus showed simutaneous organogenesis and somatic embryogenesis. Organogenesis was optimal (12.2 shoots per
culture) in 1 μM indole-3-butyric acid combined with 2.5 μM 6-benzyladenine and induction of somatic embryogenesis (16.3 embryos per culture) occurred in 2.5 μM indole-3-butyric acid combined with 2.5 μM 6-benzyladenine. Shoots rooted (100%) best in half-strength Murashige and Skoog (MS) medium supplemented with 2.0 μM indole-3-butyric acid. Early cotyledonary-stage embryos encapsulated with 3% sodium alginate and calcium nitrate (100 mM for 25 min) showed 60.6% germination in MS medium. Rooted shoots transferred to a mixture of sterile soil, sand, and peat
(1∶1∶1 by volume) showed 72% survival ex vitro. Application of these protocols would be helpful in reducing pressure in natural populations, in genetic transformation studies,
and in long-term storage of elite genotypes through synthetic seed production. 相似文献
8.
Laurent Bonneau Nicole Beranger-Novat Jeannine Monin Josette Martin-Tanguy 《Plant Growth Regulation》1967,16(1):5-10
In vitro formation of roots and somatic embryos is obtained from cotyledon explants of a Spindle tree (Euonymus europaeus L.) cultured on two different media: a medium inducing callus formation and the production of roots, and a medium inducing callus formation, root and somatic embryo production. We studied the effects of -difluoromethylornithine (DFMO), a specific, irreversible inhibitor of ornithine decarboxylase (ODC) on root and somatic embryo production, growth and titers of putrescine in Euonymus explants and explant-derived calli. Early changes in putrescine levels were detected in both cultures before the visible emergence of roots or somatic embryos. DFMO rapidly inhibited putrescine accumulation and growth in non-embryogenic calli and highly stimulated rooting activity. DFMO partially inhibited putrescine accumulation in embryogenic calli. This inhibition had no effects on callus growth but significantly reduced the time of emergence of roots and highly stimulated somatic embryo production. The relationship among putrescine, putrescine metabolism, growth, root and somatic embryo formation is discussed. 相似文献
9.
Cyclic somatic embryogenesis and efficient plant regeneration from callus of safflower 总被引:2,自引:1,他引:1
Efficient plant regeneration through somatic embryogenesis was established for safflower (Carthamus tinctorius L.) cv. NARI-6. Embryogenic calli were induced from 10 to 17-d-old cotyledon and leaf explants from in vitro seedlings. High frequency (94.3 %) embryogenic callus was obtained from cotyledon explants cultured on Murashige and Skoog’s
germination (MSG) basal medium supplemented with thidiazuron, 2-isopentenyladenine and indole-3-butyric acid. Primary, secondary
and cyclic somatic embryos were formed from embryogenic calli in a different media free of plant growth regulators, however,
100 % cyclic somatic embryogenesis was obtained from cotyledon derived embryogenic calli cultured on MSG. Somatic embryos
matured and germinated in quarter-strength MSG medium supplemented with gibberellic acid. Cotyledons with root poles or non
root poles were converted to normal plantlets and produced adventitious roots in rooting medium. Rooted plants were acclimatized
and successfully transferred to the field. 相似文献
10.
我国木兰科(Magnoliaceae)植物栽培历史悠久且种类丰富,具有很高的科研价值、观赏价值、生态价值与经济价值。但是,生境的破坏和自身繁殖能力的限制,使木兰科许多种的生存受到威胁。由于传统繁殖方式繁殖效率低下,而组织培养技术是推进木兰科种质资源保存及开发利用的有效途径,因此组织培养技术可以应用于濒危资源保护、育种和无性系苗木的商业化生产。木兰科植物的组织培养中无菌短枝扦插途径研究较多,体系已相对完善,一些种类的木兰科植物可以通过此途径得到生根苗; 而关于器官发生途径的研究相对较少,愈伤组织诱导困难及不定芽分化困难的问题仍没有得到有效解决,并且体细胞胚发生途径在国内鲜有研究。该文从无菌短枝扦插、器官发生、体细胞胚发生等不同再生途径出发,分析了外植体类型、培养基类型、生长调节剂浓度、培养条件等方面对离体生长的影响,归纳了组培过程中生根困难与褐化等技术问题与解决措施,展望了木兰科植物组织培养技术未来的研究方向,以期为木兰科植物的组培快繁技术研究提供理论依据和技术参考。 相似文献
11.
Increased endogenous indole-3-acetic acid:abscisic acid ratio is a reliable marker of Pinus massoniana rejuvenation 总被引:2,自引:0,他引:2
Y. Wang 《Biotechnic & histochemistry》2013,88(7):546-553
ABSTRACTPinus massoniana is a recalcitrant tree species for rooting in vitro. We rejuvenated 26-year-old P. massoniana trees by successive grafting. Rooting rates of rejuvenated shoots were > 83.1% after rooting induction. We compared endogenous levels of indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellins (GAs) and zeatin-riboside (ZR), and the rhizogenesis ability of axillary shoots of mature and rejuvenated materials in vitro, i.e., somaplants and grafts. Enhancement of the rooting ability of mature materials in vitro following somatic embryogenesis or repeated grafting onto juvenile rootstocks was accompanied by increased IAA and GAs levels, and by decreased ABA levels in scions used as starting material for micropropagation in vitro. Successive subcultures did not influence the rooting ability of shoots from untreated mature material. Rooting ability of shoots in vitro, however, gradually increased with subculture frequency during repeated subculturing in grafting materials. The IAA:ABA ratio in shoots in vitro after grafting five times, and consequently capable of root organogenesis, was higher than in shoots of untreated mature material incapable of root organogenesis in vitro. A high IAA:ABA ratio was detected in scions of somaplants that were capable of rooting in vitro despite subculture times. We found that the endogenous IAA:ABA ratio is a reliable marker for the recovery of root organogenesis in vitro after rejuvenating treatments for mature P. massoniana trees. 相似文献
12.
Summary St John’s wort (Hypericum perforatum) is a valuable plant used as a herbal remedy or in phytopharmaceutical drugs to treat a variety of physical ailments. Much
research has been performed to study the biochemical production of secondary metabolites of in vitro cultured plants or organs. However, all of these studies have looked at the regeneration of plants from explants in only
one genotype. In addition, no study has revealed the mechanism of plant regeneration in H. perforatum, i.e. organogenesis or somatic embryogenesis. We found that different genotypes Helos, Topas, Elixir, and Numi responded
similarly to regeneration medium. The regeneration responses (i.e. callus, root, or shool production) of identical explants
from different genotypes were similar. However, the source of explant material (leaves, hypocotyls, and roots) from the same
genotype had significant effects on the response to media and plant regeneration frequency. Using scanning electron microscopy
and light microscopy, the progress of organogenesis and embryogenesis under similar culture conditions was recorded. Root
segments were the most responsive explants, producing the maximum number of shoots per explant of all the genotypes. 相似文献
13.
Jean C. Cardoso Maisa Curtolo Rodrigo R. Latado Adriana P. Martinelli 《In vitro cellular & developmental biology. Plant》2017,53(6):619-623
Somatic embryogenesis is an important in vitro technique used to obtain Citrus sinensis (L.) Osbeck (sweet orange) plantlets for conservation, sanitation, propagation, and breeding. The induction of somatic embryogenesis from adult tissues of sweet orange could be an alternative to in vitro organogenesis from epicotyl segments, especially in seedless cultivars, where the latter is not feasible. The aim of this study was to obtain plantlets from ovary-derived somatic embryos of sweet orange cv. ‘Washington Navel’, an important seedless cultivar for citrus fresh fruit production. The explants used were pistils from flower buds, pre-anthesis, from 20-y-old plants cultivated in the field. Forty plantlets from 47 somatic embryos were obtained, in vitro-grafted, and acclimatized in greenhouse conditions. Ploidy evaluation through flow cytometric analysis, as well as the results of target region amplification polymorphism (TRAP) molecular markers confirmed the somatic origin of embryos as genetically similar to donor plants. This technique could be used for obtaining embryogenic cell suspension cultures or regenerated plants from mature tissues other than seed-derived tissues, especially for seedless genotypes. 相似文献
14.
Culture of Papaver somniferum in vitro was used for a characterisation of cell surface structures and mode of cell adhesion and cell separation during cell differentiation
and plant regeneration in somatic embryogenesis and shoot organogenesis. In early stages of somatic embryogenesis, cell type-specific
and developmentally regulated change of cell morphogenesis was demonstrated. Cell wall of separated embryonic cells were self-covered
with external tubular network, whereas morphogenetic co-ordination of adhered cells of somatic proembryos was supported by
fine and fibrillar external cell wall continuum of peripheral cells, interconnecting also local sites of cell separation.
Such type of cell contacts disappeared during histogenesis, when the protodermis formation took place. Tight cell adhesion
of activated cells with polar cell wall thickening, and production of extent mucilage on the periphery were the crucial aspects
of meristemoids. Fine amorphous layer covered developing shoot primordia, but we have not observed such comparable external
fibrillar network. On the contrary intercellular separation of differentiated cells in regenerated organs, and accepting distinct
developmental system of somatic embryogenesis and shoot organogenesis, cell adhesion in early stages and ultrastructural changes
associated with tissue disorganisation, and the subsequent reorganisation into either embryos or shoots appear to be regulatory
morphogenetical events of plant regeneration in vitro. 相似文献
15.
Comparative studies on rooting and growth performance of cuttings raised from in vitro and in vivo grown plants of Rosa damascena are described. Cuttings were treated with different auxins and upon transfer to soil their growth performance was recorded. Overall, the auxin treated cuttings of in vitro raised plants responded better than the cuttings of in vivo raised plants. Optimal response for percentage of rooting, root number, root length and bottom breaks was observed at 100 mg dm–3 IBA. The cuttings derived from in vitro raised plants showed a significantly better response for percent rooting, root number, root length and bottom buds in control treatments. 相似文献
16.
17.
Tanveer Khan Anil K. Singh R. C. Pant 《In vitro cellular & developmental biology. Plant》2006,42(6):498-501
Summary
In vitro studies related to somatic embryogenesis and organogenesis were performed in different cultivars of cotton. Gossypium hirsutum cultivars SH-131, LH-900, Hybrid H8, Khandwa-2, and Gossypium arboreum cultivars BD-1, BD-6, Sarvottam, and Jawahar Tapti were screened for their ability to regenerate in vitro. Cotyledonary leaves and hypocotyls were used as explants. Vigorous callusing was observed in G. arboreum cultivars. Globular somatic embryos were formed in BD-1, BD-6, Sarvottam, Jawahar Tapti, SH-131, and LH-900. Heart-shaped
and torpedo stages were also observed. Embryos of BD-1 and BD-6 germinated and formed distincts shoot and root poles. 2-Isopentenyladenine
(2iP) was effective in the induction of somatic embryos. Hybrid H8 and Khandwa-2 regenerated by directly forming shoots when
cultured on Murashige and Skoog (MS) medium supplemented with 6-benzyladenine and formed roots on hormone-free MS medium 相似文献
18.
Laurent Bonneau Nicole Beranger-Novat Jeannine Monin Josette Martin-Tanguy 《Plant Growth Regulation》1995,16(1):5-10
In vitro formation of roots and somatic embryos is obtained from cotyledon explants of a Spindle tree (Euonymus europaeus L.) cultured on two different media: a medium inducing callus formation and the production of roots, and a medium inducing callus formation, root and somatic embryo production. We studied the effects of α-difluoromethylornithine (DFMO), a specific, irreversible inhibitor of ornithine decarboxylase (ODC) on root and somatic embryo production, growth and titers of putrescine in Euonymus explants and explant-derived calli. Early changes in putrescine levels were detected in both cultures before the visible emergence of roots or somatic embryos. DFMO rapidly inhibited putrescine accumulation and growth in non-embryogenic calli and highly stimulated rooting activity. DFMO partially inhibited putrescine accumulation in embryogenic calli. This inhibition had no effects on callus growth but significantly reduced the time of emergence of roots and highly stimulated somatic embryo production. The relationship among putrescine, putrescine metabolism, growth, root and somatic embryo formation is discussed. 相似文献
19.
Paula P. Chee 《Plant cell reports》1995,14(12):753-757
Summary Results obtained from using root inducing compounds on Taxus species cuttings suggested that rooting could be significantly enhanced by the presence of thiamine. This observation was verified using a root inducing solution containing a set concentration of IBA (0.2%), NAA (0.1%), and supplemented with various concentrations of thiamine. The best rooting response for Taxus cuspidata stem cuttings was found using this solution supplemented with 0.08% thiamine. Rooted cuttings were easily established and developed into vigorous plants. In addition, Taxus brevifolia shoots obtained from tissue cultures via in vitro organogenesis also responded favorably to this 0.08% thiamine supplemented rooting solution. 相似文献
20.
S. J. Ochatt C. Pontécaille M. Rancillac 《In vitro cellular & developmental biology. Plant》2000,36(3):188-193
Summary The production of whole plants from explants of protein pea (Pisum sativum L.) using an efficient, reliable and rapid strategy, while maintaining trueness to type, will be required before regeneration
can be exploited for genetic transformation. Seeds of the pea genotypes Terese, Solara, Frisson and P64 (a hypernodulating
mutant line of Frisson) were surface-sterilized and imbibed overnight, whereafter embryo axes were dissected and germinated
on hormone-free medium for 7–10 d. Hypocotyl sections lacking pre-existing meristems were harvested and cultured on a range
of media with various concentrations and combinations of growth regulators in order to induce either caulogenesis or somatic
embryogenesis. Differences in responsiveness were apparent between genotypes, but regeneration via caulogenesis was consistently
more reliable than via the induction of somatic embryos. Few explants underwent somatic embryo production and their conversion
into plants has remained elusive so far, irrespective of the genotype studied. Conversely, large numbers of buds were produced
within 10 d by organogenesis, and healthy, rootable shoots were obtained. A clear relationship was observed between the growth
regulators employed for bud regeneration and shoot rooting phases and the subsequent competence of the regenerated plants
for flowering, pod formation and viable seed production. 相似文献