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1.
Optimal culture conditions for high frequency plant regeneration from excised cotyledons of Tamarindus indica were established. Maximum shoot bud differentiation (100%) occurred when the adaxial surface of the entire cotyledon (excised from 12-d old seedlings) was in contact with MS medium containing 5×10–6M BAP. On MS alone only roots were formed. Shoot or root formation was confined to nodal tissue at the top of the notch present on the adaxial surface at the proximal end of the cotyledon. Thirty-four to 95 shoots were regenerated in a 4 month period from individual cotyledons. Shoots were rooted on MS with 5.7×10–6M IAA. IAA (5.7×10–7M) alone induced complete plant formation. Regenerated plants were established in the soil with 70% success.Abbreviations BAP
6-benzylaminopurine
- KIN
kine-tin
- 2-iP
6-Y-Y-dimethylallyl aminopurine
- AdS
adenine sulphate
- IAA
indole-3-acetic acid
- IBA
indole-3-butyric acid
- NAA
1-naphthalene acetic acid
- MS
Murashige and Skoog (1962) medium 相似文献
2.
Jayanti Sen Sipra Guha-Mukherjee 《In vitro cellular & developmental biology. Plant》1998,34(4):276-280
Summary Cotyledonary nodes, excised cotyledons, and hypocotyl segments of six varieties ofVigna mungo andV. radiata have been tested for their morphogenic potential on media containing a range of hormonal combinations including benzyladenine,
kinetin, thidiazuron (TDZ), and zeatin. Multiple shoots developed on cotyledonary node explants in all varieties tested on
basal medium containing cytokinin. Presence of both the cotyledons, either full or half, resulted in a maximum number of shoots
produced. Shoot bud regeneration was achieved via meristem formation on excised cotyledons on Murashige-skoog basal medium
with B5 vitamins supplemented with TDZ. Mature plants had normal phenotypes.V. mungo var. PS1 andV. radiata var. Pusa 105 were found to be the most responsive varieties for shoot regneration. The histology ofin vitro organogenesis was studied. 相似文献
3.
Histological analysis of somatic embryogenesis induced in leaf explants ofHelianthus smithii Heiser 总被引:2,自引:0,他引:2
Summary According to the hormonal conditions, after one month of culture shoots or somatic embryos could be obtained from leaf explants ofHelianthus smithii. Well-shaped embryos developed on media containing a combination of auxin and cytokinin, while on media containing only cytokinin shoots were observed. The primary leaves of these shoots resembled cotyledons. A detailed histological study of the regeneration process on three media, containing only cytokinin or auxin, or a combination of both, allowed the origin and development of the observed structures to be determined. All three conditions induced somatic embryos, which then developed differently and, within one month, finally gave rise to the two types of structures which were initially observed.Abbrevations BAP
6-benzylaminopurine
- MES
2-(N-morpholino)ethane-sulfonic acid
- MS
medium of Murashige and Skoog
- NAA
1 -naphthaleneacetic acid
- TDZ
thidiazuron 相似文献
4.
Samira R. Mansour 《Protoplasma》1994,183(1-4):126-130
Summary Measurements of auxin and cytokinin activities in extracts ofCasuarina root nodules were made. The nodules were induced either by pure culture ofFrankia strain CgI4 or by crushed nodule inoculum. Levels of cytokinin activity were significantly higher in root nodules induced by pureFrankia culture than in those induced by crushed nodule inoculum. However, the reasons for this are unknown. Seasonal variation in levels of cytokinin activity inCasuarina nodules has also been detected.Dedicated to the memory of Professor John G. Torrey 相似文献
5.
Agrobacterium-mediated transformation of Pinus radiata organogenic tissue using vacuum-infiltration 总被引:2,自引:0,他引:2
Charity J.A. Holland L. Donaldson S.S. Grace L. Walter C. 《Plant Cell, Tissue and Organ Culture》2002,70(1):51-60
An Agrobacterium tumefaciens-mediated transformation protocol was developed for detached cotyledons of Pinus radiata zygotic embryos resulting in up to 55% of cotyledons transiently expressing the reporter gene uidA. Transient expression of uidA was improved when detached cotyledons were pre-cultured on half strength medium containing cytokinin for 7 days, wounded by vortexing and then vacuum-infiltrated in a solution of A. tumefaciens. The transformation protocol was applied both to cotyledons and also to the apical meristematic dome which was the portion of the embryo remaining after cotyledons were detached, and from which the apical shoot and axillary shoots regenerate. Molecular analysis of putatively transformed shoots regenerated either adventitiously from cotyledons or via axillary shoots from apical domes, indicated the presence of uidA and nptII genes by PCR in some of these shoots. Biochemical analysis of putatively transformed shoots using nptII ELISA indicated that they contained the nptII enzyme. However, Southern hybridisation indicated stable integration of nptII only in one shoot which was regenerated from an apical dome. Shoots regenerated from cotyledons appeared to exhibit chimeric expression and were not stably transformed. Based on a comparison of time for regeneration, technical difficulty, molecular and biochemical analysis, apical domes may be more suitable as explants for transformation and subsequent regeneration of transclones than detached cotyledons. 相似文献
6.
Maurizio Lambardi Kiran K. Sharma Trevor A. Thorpe 《In vitro cellular & developmental biology. Plant》1993,29(4):189-199
Summary Studies were undertaken to optimize tissue culture conditions for micropropagation of Aleppo pine (Pinus halepensis Mill.) from mature embryos and various explants of the embryo. Over 90% of the embryo explants gave rise to adventitious
buds within 4 wk. Intact embryos were the most suitable explants for shoot bud induction. Both isolated cotyledons and hypocotyls
produced adventitious buds, but these developed slowly and failed to elongate. N6-Benzyladenine (BA) alone at 5.0μM was the most effective cytokinin when added to gelled to gelled von Arnold and Eriksson’s (AE) medium containing 3% sucrose.
Adventitious bud development was achieved on hormone-free AE medium, and shoot elongation was optimum on three quarter-strength
Bornman’s MCM medium, with 0.1% conifer-derived activated charcoal. Shoots were multiplied on three-quarter strength MCM medium,
containing 5μM BA. To induce adventitious roots on the elongated shoots, pulse treatment with 1 mM IBA for 6 h, followed by the transfer of the shoots to sterile peat:vermiculite (1:1) mixture, was beneficial. After acclimatization
for 3 to 4 wk under mist, almost all the rooted shoots could be transplanted successfully to the greenhouse, where the plants
exhibited normal growth habit. Histologic studies on the ontogeny of adventitious shoot formation from mature embryo explants
revealed temporal structural changes in different parts of the explant. Induction of mitotic divisions on the shoot-forming
medium resulted in the formation of meristemoids in the epidermal and subepidermal layers of the explant, located initially
at both the tips of the cotyledons and the axils of adjacent cotyledons. Shoot buds arising in the axils of adjacent cotyledons
were due to new cell division and not to any preexisting meristem. 相似文献
7.
8.
Waltraud Rücker 《Protoplasma》1982,113(2):103-109
Summary The influence of a morphactin, chlorflurenol-methylester (CFM), on the growth, the morphogenesis and the isoelectric peroxidase pattern was investigated in both callus cultures (two different tissue culture strains) and multiple bud cultures ofNicotiana tabacum var.Wisconsin. CFM (range of concentration between 10–6g/ml and 10–4g/ml) was applied singly, or in combination with a cytokinin, benzylaminopurine (BAP), or with an auxin, indoleacetic acid (IAA), or with IAA plus BAP.In general, the callus growth was inhibited under the influence of CFM. In some of the experiments carried out in hormone-free media, growth stimulation was observed. Even minimal inhibition or stimulation of the callus growth was always accompanied by characteristic changes in the peroxidase patterns.The following results show the influence of the morphactin CFM on cytokinin effects (endogenous cytokinin or equally the exogenously applied cytokinin, BAP). (1) In the multiple bud cultures, BAP and CFM (both substances combined with IAA) similarly caused inhibition of root formation and stimulation of bud formation. The bands in the peroxidase patterns, characteristic of cytokinin action, were accentuated also of those bud cultures which had been treated with BAP or with CFM. (2) In the callus cultures, the cytokinin characteristics appeared under CFM influence in the peroxidase patterns of one of the tissue culture strains only when CFM was applied in combination with BAP and not in combinations of CFM with IAA.The observed morphactin-induced increase in the cytokinin effects could occur via changes in the hormone level of the tissue. 相似文献
9.
Cotyledon explants of ginseng (Panax ginseng C. A. Meyer) produced somatic embryos directly on medium without growth regulators, with 89% of the explants forming somatic
embryos. Cytokinin treatment greatly suppressed somatic embryo formation but stimulated the direct formation of adventitious
buds. BAP treatment was more effective than the kinetin treatment for adventitious bud formation. Auxin (0.05 mg/l IBA) in
combination with cytokinin enhanced adventitious bud formation, with the highest frequency, 40%, at 0.05 mg/l IBA and 5 mg/l
BAP. Adventitious buds were mainly formed near the distal portion of the cotyledons, while somatic embryos were formed near
the proximal excised margins. Shoots were developed from adventitious buds after transfer to MS medium with 10 mg/l GA3. Root formation from the shoots was obtained after the shoots were transferred to half-strength MS medium with auxin (IAA).
When the plants derived from adventitious buds were transferred to greenhouse soil, 36% were successfully acclimatized.
Received: 7 November 1997 / Revision received: 12 January 1998 / Accepted: 7 February 1998 相似文献
10.
CULTURE OF MATURE ECOTYLEDONOUS EMBRYOS OF PHASEOLUS VULGARIS AND THE NUTRITIONAL ROLE OF COTYLEDONS
Michel Monnier 《American journal of botany》1982,69(6):896-903
Embryos of Phaseolus vulgaris L. were excised from seeds and cultured with cotyledons removed to determine the actions of various cultural conditions upon embryo development. Four media were tested, but ecotyledonized embryos did not grow as rapidly on any of them as did embryos with intact cotyledons on agar-water media. Comparisons of growth of ecotyledonized embryos with embryos bearing fractions of cotyledons indicated ecotyledonized embryos cultured on nutrient media grew about as well as embryos bearing cotyledons from which 97% of the volume had been removed surgically. The final weight of ecotyledonized embryos was greater when detached cotyledons were placed near them and was even greater when extracts of detached and incubated cotyledons were employed in the nutrient medium. Benzyladenine, kinetin, gibberellic acid, indole-acetic acid, presence of sucrose, and light or dark culture failed to enhance the ability of incubated cotyledons to stimulate growth of embryos. 相似文献
11.
Joseph A. Fiola Mahmoud A. Hassan Harry Jan Swartz Robert H. Bors Ronnie McNicols 《Plant Cell, Tissue and Organ Culture》1990,20(3):223-228
The relationship between genotype, tissue age and endogenous cytokinin levels on adventitious bud formation on Lachenalia leaf tissue were investigated. The genotypes studied, showed a variation in bud formation. The hybrid explants responded differently to factorial combinations of BA and NAA. The growth regulators could not substitute for the regeneration potential of the genotype. Tissue age had a pronounced effect on regeneration potential. Young tissue formed the largest number of buds. An interaction between tissue age and genotype was detected. Cytokinin levels in young leaf tissue were higher than in older tissue. In young tissue no relationship was observed between the cytokinin level and the number of buds formed. However, in older tissue it appears as if a relatively low endogenous cytokinin level enhanced bud formation.Abbreviations BA
benzyladenine
- NAA
naphthalene-1-acetic acid
- Z
zeatin
- ZR
ribosylzeatin 相似文献
12.
Factors affecting adventitious bud induction in Pinus elliottii (Engelm.) embryos cultured in vitro 总被引:4,自引:0,他引:4
Embryos of slash pine (Pinus elliottii Engelm.) were induced to form adventitious buds when placed in culture on nutrient media supplemented with cytokinin. Buds were induced on media containing Risser & White major salts. The high content in nitrogen of Murashige & Skoog formulation seems to be deleterious for this in vitro system, since morphogenic responses were only promoted when nitrogen concentration was drastically reduced in the macronutrient formulation. Factors such as concentration of cytokinin (6-benzyladenine) and time and method of exposure (liquid or solid induction medium) strongly influenced bud formation and development. The greatest number of buds and shoots were obtained from 22.0 M cytokinin, but these shoots showed less and slower development than those induced with low dosages of cytokinin. The presence of naphthaleneacetic acid in combination with cytokinin in the induction medium decreased the frequency of bud formation.Abbreviations (BA)
6-benzyladenine
- (NAA)
1-naphthaleneacetic acid 相似文献
13.
Anwar A. Abdullah Michael M. Yeoman John Grace 《Plant Cell, Tissue and Organ Culture》1985,5(1):35-44
Adventitious buds were induced when isolated whole embryos, and excised cotyledons from treated seeds of Calabrian pine (Pinus brutia Ten.) were cultured on a cytokinin-supplemented medium. The adventitious buds formed directly from the cotyledons. The highest number of bud primordia were formed, with both embryos and excised cotyledons, after 6 weeks on a BAP — supplemented Schenk and Hildebrandt medium under a 16 h photoperiod. The buds, when separated and maintained individually on a full-strength medium without growth regulators, developed into well-formed shoots within 4 weeks. The average number of harvested shoots obtained (>1 cm in height) per seed over 24 weeks was 55; however, a maximum number of 152 shoots was obtained from one individual over the same period. The shoot forming capacity of the meristematic tissue was not lost after seven harvests. 相似文献
14.
Summary. Abaxial epidermal cells of developing faba bean (Vicia faba) cotyledons are modified to a transfer cell morphology and function. In contrast, the adaxial epidermal cells do not form
transfer cells but can be induced to do so when excised cotyledons are cultured on an agar medium. The first fenestrated layer
of wall ingrowths is apparent within 24 h of cotyledon exposure to culture medium. The time course of wall ingrowth formation
was examined further. By 2 h following cotyledon excision, a 350 nm thick wall was deposited evenly over the outer periclinal
walls of adaxial epidermal cells and densities of cytoplasmic vesicles increased. After 3 h in culture, 10% of epidermal cells
contained small projections of wall material on their outer periclinal walls. Thereafter, this percentage rose sharply and
reached a maximum of 90% by 15 h. Continuous culture of cotyledons on a medium containing 6-methyl purine (an inhibitor of
RNA synthesis) completely blocked wall ingrowth formation. In contrast, if exposure to 6-methyl purine was delayed for 1 h
at the start of the culture period, the adaxial epidermal cells were found to contain small wall ingrowths. Treating cotyledons
for 1 h with 6-methyl purine at 15 h following cotyledon excision halted further wall ingrowth development. We conclude that
transfer cell induction is rapid and that signalling and early events leading to wall ingrowth formation depend upon gene
expression. In addition, these gene products have a high turnover rate.
Correspondence and reprints: School of Environmental and Life Sciences, Biology Building, University of Newcastle, Callaghan,
NSW 2308, Australia. 相似文献
15.
Light-cytokinin interaction in shoot formation in cultured cotyledon explants of radiata pine 总被引:1,自引:0,他引:1
Previous studies utilizing cotyledon explants of radiata pine ( Pinus radiata D. Don) revealed that cytokinin was required for shoot formation. This was confirmed and extended in the present study, which also showed that light was required. As little as three days of exposure to 16 h photoperiod light at a photon fluence rate of ca 80 μmol m−2 s−1 was sufficient to give some meristematic tissue formation. Longer exposure to light increased this formation. While cytokinin must be present during the first three days in culture for shoot formation, the exposure of the cotyledons to light could be delayed at least until day 10, but after 21 days in darkness, transfer to light did not permit shoot formation. Anatomical examination of the cotyledons confirmed the morphogenetic interactions of light and cytokinin in shoot formation. The data suggest that cytokinin is directly involved in the induction of shoot initiation and both light and cytokinin are required for the development of meristematic tissue and subsequent shoot formation. 相似文献
16.
We have investigated the changes in membrane-associated calcium that occur during cytokinin induced bud formation in Funaria hygrometrica Hedw. using the fluorescent Ca2+-chelate probe chlorotetracycline (CTC). In the target caulonema cells a localization of CTC fluorescent material becomes evident at the presumptive bud site 12 h after cytokinin treatment. By the time of the initial asymmetric division this region is four times as fluorescent as the entire caulonema cell. Bright CTC fluorescence remains localized in the dividing cells of the bud. To relate the changes in CTC fluorescence to changes in Ca2+ as opposed to membrane-density changes we employed the general membrane marker N-phenyl-1-naphthylamine (NPN). NPN fluorescence increases only 1.5 times in the initial bud cell. We conclude that the relative amount of Ca2+ per quantity of membrane increases in this localized area and is maintained throughout bud formation. We suggest that these increases in membrane-associated Ca2+ indicate a localized rise in intracellular free Ca2+ concentration brought about by cytokinin action.Abbreviations BA
6-benzyladenine
- CTC
chlorotetracycline
- ER
endoplasmic reticulum
- NPN
N-phenyl-1-naphthylamine 相似文献
17.
Treatment with 6-benzylaminopurine (6-BAP; 10−5 g/ml) accelerates the growth of detached cucumber cotyledons (Cucumis sativas L.), primarily through an increased water uptake by the tissues. A comparative study of pigment composition and ultrastructure in 6-BAP treated and untreated cotyledons shows that cytokinin, in the presence of light, accelerates the transformation of etioplasts into chloroplasts. 6-BAP also enhances the synthesis of membrane precursors as indicated by the formation of a dense prolamellar body and by the persistence of a pseudo-cristalline structure in 6-BAP treated material. Stimulation of biosynthetic activity by cytokinin leads simultaneously to an increase in the rate of the pigment synthesis and to an acceleration in the building of the lamellar system. Furthermore, chloroplasts of 6-BAP treated cotyledons show abnormal features such as a striking increase in the number of thylacoids per granum and a poor development of the intergranal system. 相似文献
18.
Barry Goldfarb Glenn T. Howe Libby M. Bailey Steven H. Strauss Joe B. Zaerr 《Plant cell reports》1991,10(3):156-160
Summary The effects of high-concentration, 2-h liquid pulses of N6-benzylaminopurine (BA) and thidiazuron (TD) on adventitious bud and shoot formation were tested in cotyledons of Douglas-fir (Pseudotsuga menziesii). Seedling age proved important; on average, cotyledons from the youngest seedlings formed 10-fold more buds than cotyledons from the oldest seedlings. Optimal cytokinin concentrations for the youngest cotyledons were 400 and 800 M BA, and 100 and 200 M TD. Shoots developed best from buds induced with 300, 400, and 800 M BA. Four gelling agents were tested; BRL agarose yielded more than three times the number of buds, and Gelrite nearly twice the number of buds, as either Sigma agar or Difco Bacto-Agar. One of the best treatments (400 M BA, agarose) yielded more cotyledons with buds, and more buds per cotyledon, than when cytokinins were incorporated into the growth medium.Abbreviations BA
N6-benzylaminopurine
- TD
thidiazuron
- SH
Schenk and Hildebrandt (1972)
- NAA
1-naphthaleneacetic acid
Paper 2691 of the Forest Research Laboratory, Oregon State University, Corvallis. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the authors or Oregon State University. 相似文献
19.
K. Yamada H. Matsumoto K. Ishizuka K. Miyamoto S. Kosemura S. Yamamura K. Hasegawa 《Journal of Plant Growth Regulation》1998,17(4):215-219
The effect of disaccharide lepidimoide on light-induced chlorophyll accumulation was studied in cotyledons of sunflower (Helianthus annuus L.) seedlings and detached cucumber (Cucumis sativus L.) cotyledons. From studies on the structure-activity relationships of lepidimoide, its analogs, and sucrose with respect
to light-induced chlorophyll accumulation in the cotyledons of sunflower seedlings, both lepidimoide and the free carboxylic
acid of lepidimoide (lepidimoic acid) showed the highest promoting activity, whereas the hydrogenated lepidimoide, which lacks
a double bond in the C4, 5 position in uronic acid, showed lower activity than lepidimoide; however, sucrose exhibited very
weak activity. These results suggest that lepidimoide acts as a new type of plant growth regulator, not simply as a carbon
source providing energy. Lepidimoide promoted not only light-induced chlorophyll accumulation in sunflower cotyledons but
also light-induced 5-aminolevulinic acid content, which is considered to be a rate-limiting step in chlorophyll biosynthesis.
Lepidimoide with cytokinin stimulated the accumulation of chlorophyll and 5-aminolevulinic acid additively. In detached cucumber
cotyledons, lepidimoide also promoted light-induced chlorophyll accumulation. These results indicate that lepidimoide, in
cooperation with cytokinin, causes light-induced chlorophyll accumulation in the cotyledons of several dicot plant species
by affecting the level of 5-aminolevulinic acid.
Received April 4, 1997; accepted September 28, 1998 相似文献
20.
Increase of cytokinin activity in detached etiolated cotyledons of squash after illumination 总被引:2,自引:0,他引:2
Cytokinins nullified the lag period of the formation of chlorophyllin detached etiolated cotyledons of squash (Cucurbita moschataDuch. var. melonaeformis Makino cv. Tokyo). One hour after illumination,cytokinin activity in detached cotyledons rapidly increasedand maintained a certain level for another hour.
1 Present address: Department of Enviromental Studies, Collegeof Integrated Arts and Sciences, Hiroshima University, Hiroshima730, Japan. (Received November 25, 1976; ) 相似文献