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1.
Suspension cultures of Oryza sativa L. var IR 20 grew in Murashigeand Skoog medium (MS) supplemented with 2,4-D and kinetin ina density-dependant manner with a critical minimum inoculation-densityof 10,000 cells ml1. Conditioned medium obtained fromthese cultures and added to MS+2,4-D+kinetin induced the growthof cultures at 1,000 cells ml1. Growth stimulation byconditioned medium was mimicked by spermidine but not by otherpolyamines viz. putrescine and spermine. This is the first reportof a polyamine substituting for conditioned medium in cultures.
2 Present address: Vice-Chancellor, Pondicherry University,Pondicherry 605 014, India. 相似文献
2.
Callus of sainfoin (Onobrychis viciifolia Scop.) was initiatedfrom stem and root explants which were obtained from seedlingsgrowing in vitro, on Linsmaier Skoog (LS) medium supplementedwith 1 mg l1 2, 4-D and 1 mg l1 BA or only 1 mgl1 BA, and the Vacin and Went medium without hormones.Somatic embryos were formed on LS medium containing 1 m l1BA. Embryos developed into complete plants on filter paper saturatedwith hormone-free LS medium. Onobrychis viciifolia, somatic embryogenesis, callus culture, plant regeneration 相似文献
3.
Somatic Embryogenesis from Clonal Leaf Tissues of Cassava 总被引:3,自引:0,他引:3
Leaf lobes were isolated from palmate leaves of clonal cassava(Manihot esculenta Crantz) material growing in vitro or in glasshouseconditions and subjected to a two-stage culture procedure involvingincubation on Murashige and Skoog (MS2) basal medium supplementedwith 212 mg l1 2,4-D for 20 d (Stage I) beforetransfer to MS2 basal medium supplemented with 0.01 mg l12,4-D and 0.1 mg l1 6-benzylamino purine (BAP) (StageII medium). Embryogenetic tissues, foliose structures and somatic embryosdeveloped from leaf lobes at all Stage I 2,4-D concentrations,except on those explants isolated from shoot-tip cultures incubatedon MS2 basal medium supplemented with 0.1 mg l1 NAA and1.0 mg l1 BAP. Leaf lobes isolated directly from glasshouse plants showed optimalembryogenetic competence when subjected to a Stage I cultureperiod of 17 d, although foliose structure initiation was optimalwith shorter Stage I durations. Leaf lobes of 24 mm lengthand those isolated from phyllotaxic leaf numbers 4 and 5 showedthe greatest embryogenetic competence. Manihot esculenta, cassava, somatic embryogenesis, tissue culture, morphogenetic competence 相似文献
4.
Somatic Embryogenesis in Cassava: The Anatomy and Morphology of the Regeneration Process 总被引:2,自引:0,他引:2
Anatomical and morphological studies demonstrated that somaticembryos developed similarly on mature seed and clonal leaf explantsof cassava (Manihot esculenta Crantz) cultured for 2024d on Murashige and Skoog (MS2) basal medium supplemented with4.0 mg l1 2,4-D (Stage 1) before transfer to MS2 basalmedium supplemented with 001 mg l1 2,4-D and 01mg l1 6-benzylaminopurine (Stage II medium). Within 7d of inoculation onto Stage I medium, cell divisions occurredin the adaxial tissues of cotyledon-piece and leaf-lobe explants,and associated with this was the development of embryogeneticprotusions and ridges on the adaxial surface. Foliose structuresand somatic embryo initials developed from these tissues oncotyledon, embryonic axis and leaf-lobe explants and, when cultureswere transferred to Stage II medium, further somatic embryodevelopment occurred. Somatic embryos apparently originatedfrom groups of cells and were identified by the presence ofa closed root axis, a shoot axis and cotyledons of similar shapeand venation to those of zygotic embryos. Somatic embryos hadno vascular connection with parental cultures. Manihot esculenta, cassava, somatic embryogenesis, tissue culture, anatomy, morphology, morphogenesis 相似文献
5.
Embryogenic callus cultures were initiated from mature embryosof Lasiurus scindicus on Murashige and Skoog's medium supplementedwith 6 mg l1 2,4-Dichlorophenoxyacetic acid (2,4-D).These cultures were maintained on 2 mg l1 2,4-D. Plantletswere regenerated via somatic embryogenesis when the calli weretransferred onto hormone-free MS basal medium. Young plantswere successfully transplanted to pots and grown to maturityin a greenhouse. Grass, Lasiurus scindicus, Thar Desert, drought tolerant, somatic embryogenesis, plant regeneration 相似文献
6.
Wheat Callus Culture: the Initiation, Growth and Organogenesis of Callus Derived from Various Explant Sources 总被引:2,自引:0,他引:2
Callus was obtained from mature excised embryos of wheat, fromnodal and internodal stem segments and from rachis segmentsusing the medium of Murashige and Skoog(1962)(M medium), containing1-0mg l1 2,4-D, and from immature embryos using the mediumof Green and Phillips (1975) containing 2 mg l1 2,4-D.Callus yield from mature embryos depended upon the cultivarused. No callus could be obtained from leaf segments. Callusderived from mature embryos and nodal stem segments was successfullymaintained by serial sub-culture on the M medium containing2,4-D for up to 3 years although its growth rate declined toa lower level as culture proceeded. Such cultures consistently produced roots when transferred toa medium containing a low level of 2,4-D or no 2,4-D. The presenceof the auxin was essential for continued proliferation of thecallus tissue. Shoot initiation was infrequent, did not occurafter the first few sub-cultures and could not be enhanced byvarious auxin and cytokinin additions to the medium. Callusderived from immature embryos did not have an enhanced potentialfor shoot initiation. Triticum aestivum, wheat, callus culture, organogenesis 相似文献
7.
Somatic Embryogenesis and Analysis of Peroxidase in Cultured Lettuce (Lactuca sativa L.) Cotyledons 总被引:1,自引:0,他引:1
Somatic embryos were induced in lettuce cotyledons culturedon Murashige and Skoog's (MS) medium containing either 2 mgl1 6-benzylaminopurine (BA) and 0.2 mg l1 naphthaleneaceticacid (NAA) or 0.2 mg l1 BA and 2 mg l1 NAA. Bothcombinations induced a frequency of over 70%. The explants culturedonly in the presence of 2,4-dichlorphenoxyacetic acid (2,4-D)did not produce somatic embryos. The development of the embryoidswas studied histologically and by scanning electron microscopy.Peroxidase activity was assayed and the isoenzyme pattern ofcalluses was determined by polyacrylamide gel electrophoresis.Callus from an embryogenic line showed a much higher peroxidaseactivity than that from a non-embryogenic line, one extra peroxidaseisozyme band being present and typical of the embryogenic callus.No qualitative differences were detectable between the embryogeniccalluses. Lactuca sativa L, lettuce, somatic embryogenesis, peroxidases, isoenzymes 相似文献
8.
Bud production was investigated using algal-free cultures ofthe aquatic weed, Hydrilla verticillata. Vegetative dormantbud production in hydrilla is stimulated by a shortened photoperiodand is not temperature-dependent between 15 and 30 C. The phytochromesystem appears to be involved in this process and ABA stimulatesbud production. Artificial illumination throughout the nightprevented dormant bud production. Ethylene, applied as ethephon,reduced bud production in greenhouse cultures by 80 per centwhen applied at a level of 0.1 mgl1 ethephon at 2-d intervals. Hydrilla verticillata, aquatic plants, dormant buds, ethephon, ethylene, abscisic acid 相似文献
9.
An 18-h treatment of synchronously-grown Chlorella pyrenoidosawith 2,4-D did not significantly alter the size, dry weight,degree of synchrony, or pigment content of the cells, nor weredetectable quantities of ethylene produced. When Chlorella pyrenoidosawas treated with 5?104 M 2,4-D, there was a statisticallysignificant stimulation of both net oxygen uptake and productionwhile 5?10 M 2,4-D inhibited both processes. When Chlorellapyrenoidosa was treated with 5?104 M and 5?103M 2,4-D, significantly greater amounts of glycollate were presentin the culture medium, even though an assay for glycollate dehydrogenaseshowed that the activity of this enzyme from 2,4-D-treated Chlorellapyrenoidosa was three times greater than in control cells. Looselybound 2,4-D was partitioned from a nonaqueously isolated chloroplastfraction, while other cell fractions failed to show detectablequantities of 2,4-D. It is postulated that in Chlorella pyrenoidosathe chloroplast is a target for 2,4-D action and that interferencein photorespiratory processes may underlie the observed responses. 相似文献
10.
The Growth, Anatomy and Morphogenetic Potential of Callus and Cell Suspension Cultures of Hevea brasiliensis 总被引:1,自引:0,他引:1
Callus cultures have been initiated from stem explants of youngplants of Hevea brasiliensis and maintained over long periodsat 30 ?C by serial subculture in Murashige and Skoog mediumcontaining 2 mg 11 2,4-D and 0.5 mg 11 kinetin.Newly-initiated cultures spontaneously initiated roots but,on serial subculture, this property was lost and the culturesbecame heterogeneous (consisting of proliferating light segmentsand darker compact non-growing segments). Serially propagatedcultures continued to differentiate a few scattered latex vesselscontaining particulate material similar to that in the rootlaticifers. This callus (O callus) did not yield a growing cellsuspension when transferred to agitated liquid medium. However,the large cell aggregates which could be recovered after twopassages in liquid medium, when again grown on solid mediumyielded a highly friable light-coloured fast-growing homogeneouscallus (R callus) which retained its distinctive character onsubculture. This callus when transferred back to agitated liquidmedium yielded a fine rapidly growing cell suspension culturewhich could be serially propagated at 30 ?C in the same mediumas that used for callus culture. Both the O and R cultures were2,4-D dependent, but differed in their responses to 2,4-D. Bothretained their diploid character when serially propagated. Serially-propagatedsuspensions came to contain a proportion of polyploid cells.When the suspensions were maintained for several months withoutsubculture the larger cell aggregates which developed gave riseto embryo-like structures. Attempts to promote the further developmentof these embryo-like structures into plantlets were unsuccessful. 相似文献
11.
Callus cultures of Ipomoea pes-caprae and I. batatas were establishedon MS medium containing 105 M 2,4-D and 108 Mbenzyladenine. Ipomoea pes-caprae calli exhibited green pigmentationand grew better in the light than in darkness. Callus tissuesof I. batatas showed a pale-yellow colouration and they grewat the same rate in light as in dark conditions. I. pes-capraeand I. batatas callus cultures were sensitive to the presenceof 60 mM NaCl in the culture medium, the growth of the formerbeing more sensitive in light than in darkness. The significanceof the responses of I. pes-caprae callus cultures in relationto the mechanism of salt tolerance is discussed. Ipomoea batatas, Ipomoea pes-caprae, sweet potato, railroad vine, callus cultures, salinity, light 相似文献
12.
Ethylene production from leaf discs of dwarf bean (Phaseolausvulgaris L.) was less than 02 nl g1 h1 at 5 Cbut rapidly increased tenfold on transfer to 25 C. The lowethylene production at 5 C and the potential for overshootproduction on transfer to 25C were not associated with accumulationof the ethylene synthesis intermediate 1-aminocyclopropane-1-carboxylicacid (ACC). Addition of exogenous ACC to leaf discs incubatedat 5C increased ethylene production, while similarly incubatedleaf discs did not synthesize increasing amounts of endogenousACC until they were transferred to 25 C. The basis for theovershoot in ethylene production when leafdiscs were transferredfrom 5 to 25 C appears to reside in changes to the pathwayleading to the synthesis of ACC or an earlier intermediate inthe pathway of ethylene biosynthesis. Ethylene, 1-aminocyclopropane-l-carboxylic acid, Phuseolru vulgaris L., dwarf bean, temperature 相似文献
13.
KARGIOLAKI HARIKLIA; OSBORNE DAPHNE J.; THOMPSON FRANK B. 《Journal of experimental botany》1991,42(9):1189-1198
Differences in premature leaf abscission and in visible steminjury in genetic lines of poplar followed continuous fumigationswith air pollutant levels of SO2 (90100 nl l1)and O3 (7080 nl l1) either separately or together.The clones used were: Populus deltoides var. missiouriensisMarsh., P. nigra cv. italicd L., and the hybridsP. nigra cv. italica xP. deltoides (He-X/3) andP. nigra cv.italica x P. nigra cv. Serres(He-K/7). While most leaf abscission occurred within 20 d fromthe start of fumigation, stem lesions (intumescences), appearedonly after 72 d. Their anatomical characteristics include theformation of lysigenous aerenchyma in the lower parts of theintumescence, the sloughing of superficial cells from the injuredarea, and the development of crystalline formations on the surfaceof the lesions. P. deltoides exhibited the least morphologicalresponse to the gases. Ethylene released from fumigated leaves was determined at thesame gas concentration of SO2 (100 nl l1), O3 (75 nll1) and their mixture. Leaves of P. deltoides consistentlyshowed the lowest ethylene production after the gas treatments.P. italica production was higher but was littlealtered by the treatments. The two hybrids He-X/3 and He-K/7showed the greatest increases in ethylene evolution with time.With He-K/7 exposed to the gas mixture the production of ethylenedecreased after the initial sharp rise during days 12,and reflected the considerable leaf damage observed after day3. The results suggest that sensitivity to air pollution, (as shownby leaf abscission and the formation of stem intumescences)can be correlated with the level of pollutant-induced ethyleneevolution from leaves. Initially high levels could induce abscission,whilst prolonged production could be responsible for intumescenceinitiation. The discussion proposes a series of events fromSO2 and/or O3 entry into the leaf and the physiological reasonsfor the clonal differences. Key words: Sulphur dioxide, ozone, ethylene, poplar, leaf abscission, stem lesions 相似文献
14.
Taro callus maintained on Knop's medium with 2, 0·2 or0·02 mg l1 2,4,5-trichiorophenoxyacetic acid (2,4,5-T)or Linsmaier-Skoog (LS) containing 1 mgl1 of the cytokininadenine-N-benzyl-9-tetrahydro-2H- pyran-2-yl (SD8339) or 6 dimethylaininopurineand 0·1 mgl1 -naphthaleneacetic acid underwenta transition to a stable organized growth form which is referredto as a calloid. On transfer to LS medium th 0·2 mgl12,4,5-T in the absence of cytokinin the calloid reverts backto callus. Colocasia esculenta(L.)Schott, taro, callus, calloid, in vitro selection, histology, micropropagation, tissue culture, cytokinin 相似文献
15.
Ontogenesis, Differentiation and Precocious Germination in Anther-derived Somatic Embryos of Grapevine (Vitis vinifera L.): Proembryogenesis 总被引:1,自引:0,他引:1
Histological steps of callogenesis and proembryogenesis in anthercultures ofVitis vinifera L. Grenache noir aredescribed. Embryogenic calli were obtained on Nitsch and Nitschmedium supplemented with 1mgl-12,4-dichlorophenoxyacetic acid(2,4-D) and 0.25mgl-1benzylaminopurine (BAP). Calli were initiatedfrom anther connective cells only and no division of microsporesoccurred. The embryos were hence of somatic origin. Proembryosdeveloped either directly (i.e. without intervening callus)from the endothecium, or indirectly from the connective-derivedcallus. In both cases, proembryos originated from single cells.They developed from starchy differentiated cells of a predeterminedtype. The polarity of the somatic proembryo was establishedfrom the first divisions and it was marked by precocious developmentof an easily recognizable suspensor. Other analogies with thedevelopment of the zygote are also emphasised. Vitis vinifera L.; grapevine; somatic embryogenesis; proembryogenesis; histology 相似文献
16.
Growth kinetics of Datura innoxia batch suspension cultureswen monitored by a Klett-turbidimetric technique. While cultured. wt varied linearly with Klett units, f. wt and packed cellvolume did not. Turbidimetrically determined doubling timeswere highly reproducible. The method proved to be useful inthe determination of acutely lethal conantrations of a seriesof anti-metabolites. In certain circumstances, aggregate dissociation in batch suspensioncultures of D. innoxia was found to be coupled to growth rate.Suspensions maintained with 105 M 2,4-D exhibited a relativelyslow growth rate with a high degree of aggregate dissociation:104 M 2,4-D promoted a maximum growth rate, but dramaticallysuppressed aggregate dissociation. At 105 M 2,4-D, themitotic index of smaller-aggregate fractions was greater thanthe mitotic index of the large-aggregate fraction. At 105M 2,4-D the converse was observed. Supraoptimal 2,4-D concentrationsthus enhanced both aggregate dissociation and the growth ofsmaller aggregates. When present in concentrations promoting optimal growth. malicand succinic acids caused a decrease in aggregate dissociation.Casein hydrolysate dramatically enhanced growth, but did notaffect aggregate dissociation to the same degree as 2,4-D orthe Krebs cycle organic acids. Suggestions are made concerningmedium composition to be used in future mutant selection schemesusing D. innoxia. Datura innoxia (Miller), suspension culture, growth kinetics, mitotic index, 2,4-dichorophenoxy acetic acid 相似文献
17.
Significant amounts of ethylene was produced by Pseudomonassolanacearum (all strains), P. syringae pv. phaseolicola (Kudzustrains isolated from Pueraria lobata) and Erwinia rhapontici(2 strains out of 22) out of 24 species, 3 subspecies and 38pathovars of plant pathogenic bacteria tested in yeast extract-peptonebroth. The bean strains of P. syringae pv. phaseolicola causinghalo blight in kindney bean plants did not produce ethylene.The Kudzu strains produced ethylene at a rate of 7 to 100?109nl cell1 h1, which was 500 to 1,000 times higherthan that of P. solanacearum and several times higher than thatof Penicillium digitatum, the most potent ethylene producerknown among microorganisms. The presence of living cells was essential for ethylene productionby the Kudzu strains. The bacterium effectively produced ethylenefrom amino acids such as glutamate, aspartate and their amides.Although glucose and succinate were also good substrates forethylene biosynthesis, the rate of ethylene production was significantlysmaller than that with glutamate. Methionine, which is knownas the precursor of ethylene in plants, had no effect on ethyleneproduction by the bacterium. 1-Aminocyclopropane-1-carboxylicacid (ACC) also had no effect on ethylene production, and therewas not enough ACC in the bacterial cells to account for thehigh rate of ethylene production. Ethylene production from glutamatewas inhibited by n-propylgallate and EDTA, but not by aminoethoxyvinylglycine.These results indicate that ACC is not involved as an intermediatein the process of ethylene biosynthesis by the bacterium, suggestingthe presence of a pathway different from that of plant tissues. (Received September 4, 1984; Accepted October 27, 1984) 相似文献
18.
Somatic Embryogenesis and Plant Regeneration from Cultured Leaf Explants of Zea mays 总被引:4,自引:0,他引:4
Young leaf segments of Zea mays L. seedlings were cultured onMurashige and Skoog's basal nutrient medium supplemented with2 mg l1 2, 4-D and sub-cultured on medium containing8 mg l1 2,4-D. Two types of callus tissues appearedembryogenicand non-embryogenic. The embryogenic callus tissue producednumerous somatic embryos which on transfer to media containinglow amounts of 2,4-D or ABA produced plantlets. Callus tissuesexhibited embryogenic potential for more than 1 year. Zea mays L. cv. Ageti-76, Zea mays L. cv. N-L-D-Comp., maize, leaf, callus, somatic embryogenesis, regeneration 相似文献
19.
HORNER M.; McCOMB J. A.; MoCOMB A. J.; STREET H. E. 《Journal of experimental botany》1977,28(6):1365-1372
Anthers of Nicotiana tabacum produce ethylene when culturedfor plantlet production. The rate is at a maximum 12weeks after the onset of culture. Charcoal in the medium increasesthe proportion of androgenic anthers in N. tabacum and severalother Nicotiana species. The level of ethylene in culture vesselsis reduced by charcoal. However, complete removal of ethylenedoes not significantly alter the incidence of androgenesis,nor does continuous flushing of cultures with air. It is concludedthat although charcoal reduces ethylene in the gas phase ofthe cultures its effect on androgenesis is exerted through someother mechanism. 相似文献
20.
Embryogenic cell suspension cultures were established from calliderived from young leaves of sugarcane (Saccharum officinarumL.) by placing them in liquid medium containing 5 per cent coconutwater (CW), 23 mg 11 2, 4-D and 500 mg 11casein hydrolysate (CH). The cultures were maintained by transferring2.55.0 ml of the suspension to 35 ml of fresh mediumevery 45 days. Organized structures resembling the earlystages of embryogeny were formed when 2, 4-D in the medium waslowered (0.11.0 mg 11) but these did not developbeyond the globular or early scutellar stages. High levels ofsucrose (610 per cent) promoted the formation of proembryoids.Plating of the suspension on MS agar medium supplemented with0.252.0 mg 11 2, 4-D, 5 per cent CW, 500 mg 11CH, with or without activated charcoal, resulted in the formationof embryogenic calli. A large number of embryoids were formedin media containing lower 2, 4-D concentrations. Transfer ofembryoids to half-strength MS medium with 6 per cent sucroseestablished plantlets which were successfully transferred tosoil. Saccharum officinarumL, sugarcane, suspension culture, embryogenesis, regeneration 相似文献