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1.
Light quality influences germination, root growth and hypocotyl elongation in somatic embryos but not in seedlings of norway spruce 总被引:4,自引:0,他引:4
Harald Kvaalen Maigull Appelgren 《In vitro cellular & developmental biology. Plant》1999,35(6):437-441
Summary We studied how light from different light sources influences germination and postgerminative growth of plants from somatic
embryos and seeds of Norway spruce (Picea abies [L.] Karst). Somatic embryos of three spruce genotypes and seeds were subjected to light from commercially available light
sources: Philips TLD Blue 18W/18 (BL), Osram Fluora (FL), Philips Cool White TL 50W/33 (CW), Osram Warm White 18W/30 (WW),
Philips Yellow 36W/16 (YE) and Philips TLD Red 36W/15 (RE), 18 h a day, with a photon flux (PAR) at 30 μmol m−2 s−1. After 6 wk the germination frequencies of the somatic embryo-derived plantlets were 50% under BL and 98% under RE. The corresponding
mean root lengths were 6.7 and 15.4 mm. In somatic embryo-derived plantlets cultured under BL, FL, CW and WW, both roots and
hypocotyls turned brown, presumably due to production of phenolic substances. Browning was less severe in somatic embryo-derived
plantlets cultured under RE and YE. Under RE, the epicotyl elongated in 37% of the plantlets after 6 wk, compared with 70%
under the other light sources. Seed germination and postgerminative seedling growth was modestly influenced by light from
these light sources. RE and WW initially delayed germination as compared with BL, FL and CW, but after 2 wk, more than 90%
of the seeds had germinated under all light sources. In conclusion, germination and postgerminative growth of somatic embryos
of spruce is sensitive to differences in light quality, whereas seed germination and seedling growth is not. 相似文献
2.
Wei Tang Zhongchen Guo Fan Ouyang 《In vitro cellular & developmental biology. Plant》2001,37(5):558-563
Summary Mature zygotic embryos of eight (open-pollinated) families of loblolly pine (Pinus taeda L.) were cultured on eight different basal salt formulations, each supplemented with 36.2 μM 2,4-dichlorophenoxyacetic acid, 17.8 μM 6-benzyladenine, 18.6 μM kinetin, 500 mg l−1 casein hydrolysate, and 500 mg l−1
l-glutamine for 9 wk; embryogenic tissue was formed on cotyledons, hypocotyls, and radieles of mature zygotic embryos. Callus
was subcultured on the callus proliferation medium, the same as the induction medium but with one-fifth concentration of auxin
and cytokinin for 9 wk. On this medium a white to translucent, glossy, mucilaginous embryogenic callus containing embryogenic
suspensor masses (ESMs) was obtained. The highest frequency of explants forming embryogenic tissue, 17%, occurred on a modified
Murashige and Skoog salts basal medium containing the concentration of KNO3, Ca(NO3)2·4H2O, NH4NO3, KCl, ZnSO4·7H2O, and MnSO4·H2O, 720, 1900, 400, 250, 25.8, and 25.35 mg l−1, respectively. Embryogenic suspension cultures were established by culturing embryogenic callus in liquid callus proliferation
medium. Liquid cultures containing ESMs were transferred to medium containing abscisic acid, polyethylene glycols, and activated
charcoal for stimulating the production of cotyledonary somatic embryos. Mature somatic embryos germinated for 4–12 wk on
medium containing indole-butyric acid, gibberellic acid, 6-benzyladenine, activated charcoal, and reduced sucrose concentration
(15 g l−1). Two hundred and ninety-one regenerated plantlets were transferred to a perlite:peatmoss:vermiculite (1∶1∶1) mixture, then
the plants were transplanted to soil in the earth, and 73 plantlets survived in the field. 相似文献
3.
A system for rapid plant regeneration through somatic embryogenesis from shoot tip explants of sorghum [Sorghum bicolor (L.) Moench] is described. Somatic embryogenesis was observed after incubation of explants in dark for 6–7 weeks through
a friable embryogenic callus phase. Linsmaier and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid (2 mg l−1) and kinetin (0.1 mg l −1) was used for induction of friable embryogenic calli and somatic embryos. Germination of somatic embryos was achieved about
5 weeks after transfer onto Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (2 mg l−1) and indole-3-acetic acid (0.5 mg l −1) under light. Seeds from in vitro-regenerated plants produced a normal crop in a field trial, and were comparable to the crop grown with the seeds of the mother
plant used to initiate tissue culture. The simplicity of the protocol and possible advantages of the system for transformation
over other protocols using different explants are discussed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
4.
Plant regeneration from protoplast culture of Crocus cancellatus was investigated using regenerable embryogenic calli obtained from shoot meristem culture on LS (Linsmaier and Skoog, 1965)
medium containing 4 mg l−1 kinetin and 1 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D). Protoplasts were isolated directly from embryogenic calli. The best protoplast growth
was found on those embedded in Ca-alginate beads and cultured with nurse cells in MS (Murashige and Skoog, 1962) medium supplemented
with 2 mg l−1 kinetin, 1 mg l−1 2,4-D and 100 mg l−1 ascorbic acid at 25 °C in darkness. After 4–5 weeks of culture, microcalli appeared on the surface of the Ca-alginate beads,
but the protoplasts without immobilization in Ca-alginate beads showed very low cell division. Growth of the microcalli in
the medium with nurse cells was much better than in the medium without nurse cells. Transferring beads onto half strength
MS medium supplemented with 0.2 mg l−1 kinetin and 0.1 mg l−1 2,4-D, increased the growth of embryogenic calli. Somatic embryo development was observed either on half strength MS medium
growth regulator free or with 1 mg l−1 abscisic acid. Matured embryos germinated on half strength MS medium containing 25 mg l−1 of gibberelic acid. Plantlet formation was obtained on half strength MS medium containing 1 mg l−1 6-benzyladenine and 1 mg l−1 α-naphthaleneacetic acid at 20 °C in a 16/8 h light/dark cycle.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
5.
Embryogenic tissue was induced from developing immature zygotic embryos in Bunge’s pine (Pinus bungeana Zucc. ex Endl.). Induction rate reached 84.4% with our best treatment. Zygotic embryos were dissected from megagametophytes
and inoculated on different induction media, DCR1 (Gupta PK, Durzan DJ (1985) Plant Cell Rep 4:177–179), BM1 (Gupta PK, Pullman G (1991) U.S. Patent No. 5,036,00) and MSG (Becwar MR, et al. (1988) Somatic cell genetic of woody plants.
Kluwer Academic Publishers, Dordrecht, pp. 1–18), supplemented with 2,4-dichlorophenoxyacetic acid (2, 4-D) and 6-benzylaminopurine
(BA). DCR1 was the best medium for initiating embryogenic tissue. Induction rates were affected significantly by developmental stages
of explants. The highest induction rate was obtained with embryos collected on either June 20 or June 30 with 10 mg l−1 2, 4-D and 4 mg l−1 BA. Embryogenic tissue was subcultured monthly on DCR1 medium supplemented with 0.3 mg l−1 2, 4-D and 0.2 mg l−1
α-naphthaleneacetic acid. In order to enhance embryo maturation, embryogenic tissue was transferred onto DCR1 medium for two weeks, in which 1,000 mg l−1 myo-inositol was included and all plant growth regulators were eliminated. This pretreated tissue was then transferred onto
a maturation medium that was DCR1 medium containing 50 g l−1 sucrose and 0.1 mg l−1 indolebutyric acid. In this study, benefits of embryo maturation were not observed when abscisic acid and polyethylene glycol
were applied in the culture. 相似文献
6.
The turf-type bermudagrasses are genetically variable and do not respond uniformly to tissue culture and plant regeneration
protocols. We evaluated the callus induction response of two explant types, young inflorescences and nodes, from multiple
genotypes including triploid TifSport, TifEagle, and Tift97-4 and tetraploid Tift93-132, Tift93-135, Tift93-156 and Tift93-157
on MS medium supplemented with 1–1.5 mg l−1 2,4-D + 0.01 mg l−1 BA + 1.16 g l−1 proline. Four types of callus were observed. Type I was fluffy, soft, and white non-embryogenic callus, common to all cultures.
Type II was globular, transparent, and hard, but sticky callus, which was pre-embryogenic and could be selected for subculture.
Type III callus was transparent, compact, and embryogenic. Type IV callus was opaque white and compact. Both Type III and
Type IV calluses were embryogenic and regenerative. A combination of gelling agents in the medium (2 g l−1 Gelrite and 5 g l−1 agar) improved callus quality and increased the rate of compact callus formation during subculture. Embryogenesis from compact
callus was observed in TifEagle, TifSport and Tift93-132, and shoots were regenerated on MS medium with 0.1 mg l−1 2,4-D + 0.5–4.0 mg l−1 BA. Low intensity light treatment (30 μmol m−2 s−1 of cool white fluorescence) to callus before regeneration greatly enhanced regeneration frequency from 6.7% to 40% in recalcitrant
TifSport. 相似文献
7.
The effects of UVB on the kinetics of stem elongation of wild type (WT) and photomorphogenic mutants of tomato were studied
by using linear voltage transducers connected to a computer. Twenty-one or twenty-six-day-old plants, grown in 12 h white
light (150 μmol m−2 s−1 PAR)/12 h dark cycles, were first transferred to 200 μmol m−2 s−1 monochromatic yellow light for 12 h, then irradiated with 0.1 or 4.5 μmol m−2 s−1 UVB for 12 h and finally kept in darkness for another 24 h. The measurements of the kinetics of stem elongation started after
4 h under yellow light. Significant differences in stem growth during the irradiation with yellow light, as well as during
the dark period, were found between the genotypes. In darkness, the magnitude of stem growth followed the order: tri > AC = fri > MMau > hp1. Two factors determined the large differences of growth in darkness: 1) the different stem elongation rate (SER) and 2) the
different duration of the growing phase among the genotypes. In darkness the stem growth of au and hp1 mutants lasted for about 18 h, whereas it continued for the whole experimental period (36 h) in the other genotypes. UVB
irradiation substantially reduced elongation growth of all genotypes (4.5 μmol m−2 s−1 being more effective than 0.1 μmol m−2 s−1). Both fluence rates of UVB induced a detectable reduction of SER already after 15 min of irradiation. Red light inhibited,
while far red light promoted stem growth of all the genotypes tested. fri (phyA null), tri (phyB1 null), hp1 (exhibiting exaggerated phytochrome responses) mutants and WT tomato showed similar levels of UVB–induced inhibition of growth,
while the aurea mutant showed the largest growth inhibition during the 12 h of irradiation. These results indicate that phytochrome is not
directly involved in UVB control of stem elongation. The results of dichromatic irradiations UVB + red or UVB + far red indicate
the presence of distinct and additive action of UVB photoreceptor and of the phytochrome system in the photoregulation of
stem growth.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
8.
Traud Winkelmann Janine Specht Margrethe Serek 《Plant Cell, Tissue and Organ Culture》2006,86(3):337-347
A protocol for plant regeneration from protoplasts has been developed, and then successfully applied to different genotypes of Cyclamen persicum Mill. Protoplasts were isolated from embryogenic suspension cultures by enzymatic digestion in 2% cellulase R10 and 0.5% macerozyme R10. Yields obtained varied between 1 and 5 × 105 protoplasts per gram fresh mass depending on the genotype. Protoplasts were immobilized in alginate films, which promoted proper cell wall regeneration. The highest cell division frequencies were found in modified Kao and Michayluk (1975, Planta 126:105–110) medium containing the same types and concentrations of plant growth regulators that were applied for suspension culture (2.0 mg l−1 2,4-dichlorophenoxyacetic acid and 0.8 mg l−1 6-(γ,γ-dimethylallylamino)purine). Cell division was recorded for all 11 tested genotypes in frequencies of up to 12% and 18% after 7 and 14 days, respectively. However, cell division frequency varied strongly between different genotypes. After 4–6 weeks calluses were released from the alginate films and further cultured on hormone-containing medium for continued growth or transferred to hormone-free medium for regeneration of somatic embryos. Plant regeneration via somatic embryogenesis succeeded in 9 out of the 11 genotypes under investigation. Up to now protoplast-derived plants from four genotypes have been successfully transferred to soil. 相似文献
9.
Shinjiro Ogita Hamako Sasamoto Edward C. Yeung Trevor A. Thorpe 《In vitro cellular & developmental biology. Plant》2001,37(2):268-273
Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l−1 glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic
and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic
aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation
of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing
(2400 mg l−1) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic
aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level
of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell
masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues. 相似文献
10.
Silvia Karina Vila Hebe Yolanda Rey Luis Amado Mroginski 《Journal of Plant Growth Regulation》2007,26(3):268-277
Factors affecting somatic embryogenesis induction and conversion in paradise tree (Melia azedarach) were evaluated. Somatic embryogenesis was influenced by plant growth regulators, explant stage, carbohydrate source and
concentration, gelling agents, light, and induction times. MS medium with 4.54 μM thidiazuron (TDZ) was optimal for the induction
of embryogenic tissue. Zygotic embryos that were 1-1.5 mm long (torpedo and early cotyledonal stage) had a greater embryogenic
response than smaller or larger embryos and better conversion of somatic embryos into plants. In general, embryos that formed
in medium containing 1% or 5% carbohydrate were hyperhydrics or fused, respectively, whereas those that formed in medium with
a carbohydrate concentration of 3% had better morphology. Raffinose at 3% yielded satisfactory somatic embryo induction with
good morphology and the best values of conversion into plants. Induction and conversion of somatic embryos were superior on
medium solidified with agar A-1296. The explants maintained under 160 μmol m−2 s−1 or 1 week in darkness and later 160 μmol m−2 s−1 produced a significantly higher embryogenic index. Only 4 days of treatment on induction medium, with either raffinose or
sucrose at 3% as a carbohydrate source, were required to induce somatic embryogenesis, but longer exposure, until 18 days,
increased the yield and improved the morphology of somatic embryos. 相似文献
11.
Ganka Chaneva Sevdalina Furnadzhieva Kaledona Minkova Jaromir Lukavsky 《Journal of applied phycology》2007,19(5):537-544
The effect of light intensity (50–300 μmol photons m−2 s−1) and temperature (15–50°C) on chlorophyll a, carotenoid and phycobiliprotein content in Arthronema africanum biomass was studied. Maximum growth rate was measured at 300 μmol photons m−2 s−1 and 36°C after 96 h of cultivation. The chlorophyll a content increased along with the increase in light intensity and temperature and reached 2.4% of dry weight at 150 μmol photons
m−2 s−1 and 36°C, but it decreased at higher temperatures. The level of carotenoids did not change significantly under temperature
changes at illumination of 50 and 100 μmol photons m−2 s−1. Carotenoids were about 1% of the dry weight at higher light intensities: 150 and 300 μmol photons m−2 s−1. Arthronema africanum contained C-phycocyanin and allophycocyanin but no phycoerythrin. The total phycobiliprotein content was extremely high,
more than 30% of the dry algal biomass, thus the cyanobacterium could be deemed an alternative producer of C-phycocyanin.
A highest total of phycobiliproteins was reached at light intensity of 150 μmol photons m−2 s−1 and temperature of 36°C, C-phycocyanin and allophycocyanin amounting, respectively, to 23% and 12% of the dry algal biomass.
Extremely low (<15°C) and high temperatures (>47°C) decreased phycobiliprotein content regardless of light intensity. 相似文献
12.
M.N. Ogburia 《Biologia Plantarum》2003,47(3):429-432
Explants of four F1 hybrids (OMR 36-41/1, OMR 36-41/2, OMR 36-41/4 and OMR 36-41/5) and two cultivars (Rayong 1 and Rayong 60) of cassava (Manihot esculenta Crantz) were subjected to different combinations of 2,4-dichlorophenoxyacetic acid (2,4-D), 1-naphthaleneacetic acid (NAA),
kinetin (KIN) and N6-benzylaminopurine (BAP) to induce somatic embryogenesis, organogenesis and micropropagation. Shoot apices of the F1 hybrids exhibited higher frequency (62 – 74 %) of proliferation of somatic embryos than the cultivars (21 – 43 %) in Murashige
and Skoog basal medium supplemented with 8 mg dm−3 2,4-D and 0.5 mg dm−3 NAA. Nodal explants of regenerated plantlets were rapidly micropropagated with 90 % efficiency on a medium containing 0.1
mg dm−3 NAA and 0.05 mg dm−3 BAP irrespective of explant source.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
In this paper, we would like to show unexpected morphogenic potential of cell suspensions derived from seedling explants of
Gentiana kurroo (Royle). Suspension cultures were established with the use of embryogenic callus derived from seedling explants (root, hypocotyl
and cotyledons). Proembryogenic mass proliferated in liquid MS medium supplemented with 0.5 mg l−1 2,4-D and 1.0 mg l−1 Kin. The highest growth coefficient was achieved for root derived cell suspensions. The microscopic analysis showed differences
in aggregate structure depending on their size. To assess the embryogenic capability of the particular culture, 100 mg of
cell aggregates was implanted on MS agar medium supplemented with Kin (0.0–2.0 mg l−1), GA3 (0.0–2.0 mg l−1) and AS (80.0 mg l−1). The highest number of somatic embryos was obtained for cotyledon-derived cell suspension on GA3-free medium, but the best morphological quality of embryos was observed in the presence of 0.5–1.0 mg l−1 Kin, 0.5 mg l−1 GA3 and 80.0 mg l−1 AS. The morphogenic competence of cultures also depended on the size of the aggregate fraction and was lower when size of
aggregates decreased. Flow cytometry analysis reveled luck of uniformity of regenerants derived from hypocotyl suspension
and 100% of uniformity for cotyledon suspension. 相似文献
14.
Sun Hee Woo Arun Nair Taiji Adachi Clayton G. Campbell 《In vitro cellular & developmental biology. Plant》2000,36(5):358-361
Summary Plants were regenerated from cotyledon tissue of greenhouse grown seedlings of common buckwheat (Fagopyrum esculentum Moench.). Maximum callus regeneration was induced on Murashige and Skoog (MS) medium containing 2,4-D (2.0 mg l−1) and kinetin (KIN) (0.2 mg l−1) and either 3 or 6% sucrose. Friable callus was transferred to MS media containing KIN and benzylaminopurine (BAP) at varied
concentrations for embryogenic callus induction. The optimum medium for embryogenic callus induction was found to be MS medium
supplemented with 0.2 mg l−1 KIN, 2.0 mg l−1 BAP and 3% (w/v) sucrose. Variation of sucrose from 3 to 6% did not show any significant effect on callus induction or embryogenesis.
Regeneration of embryonic callus varied from 13 to 32%. Whole plants were obtained at high frequencies when the embryogenic
calluses with somatic embryos and organized shoot primordia were transferred to half-strength MS media with 3% sucrose. Regenerated
plants after acclimation were transferred to greenhouse conditions, and both vegetative and floral characteristics were observed
for variation. This regeneration system may be valuable for genetic transformation and cell selection in common buckwheat. 相似文献
15.
Yuexia Wang Bridget A. Ruemmele Joel M. Chandlee W. Michael Sullivan Jane E. Knapp Albert P. Kausch 《In vitro cellular & developmental biology. Plant》2002,38(5):460-467
Summary Embryogenic callus induction and plant regeneration systems have long been established for creeping bentgrass (Agrostis palustris Huds.), but little research has been reported on optimal medium for embryogenic callus induction and plant regeneration in
velvet bentgrass (Agrostis canina L.), colonial bentgrass (Agrostis capillaries L.), and annual bluegrass (Poa annua L.). The present study compared 14 callus induction media and eight regeneration media for their efficacies on embryogenic
callus induction and plant regeneration in these four species. The embryogenic callus initiation media contained the Murashige
and Skoog inorganic salts and vitamins supplemented with 2,4-dichlorophenoxyacetic acid or 3,6-dichloro-anisic acid and 6-benzyladenine.
l-Proline or casein hydrolyzate was included in some media to stimulate embryogenic callus formation and plant regeneration.
The frequencies of embryogenic callus formation ranged from 0% to 38% and exhibited medium differences within each of the
four species. Callus induction media, plant regeneration media, and genotypes affected plant regeneration rates, which varied
between 0% and 100%. The embryogenic callus induced on Murashige and Skoog medium supplemented with 500 mgl−1 casein hydrolyzate, 6.63 mg l−1 (30 μM) 3,6-dichloro-anisic acid and 0.5–2.0 mg l−1 (2–9 μM) 6-benzyladenine had much higher regeneration rates than those formed on other callus induction media. Embryogenic callus
of annual bluegrass had higher regeneration rates than those of bentgrass species. MSA2D, a media containing 2 mgl−1 (8 μM) 2,4-dichlorophenoxyacetic acid, 100 mgl−1
myo-inositol, and 150 mgl−1 asparagine, was effective in promoting embryogenic callus formation in creeping bentgrass but not in colonial and velvet
bentgrasses and annual bluegrass. 相似文献
16.
The effects of antibiotics commonly used in Agrobacterium-mediated transformation were studied on Pinus pinaster tissues. Embryogenic tissue growth from three embryogenic lines and adventitious bud induction from cotyledons from three open-pollinated seed families were analysed. Cefotaxizme, carbenicillin and timentin commonly used for Agrobacterium elimination, at concentrations of 200–400 mg l −1 did not inhibit the embryogenic tissue growth on filter paper nor as clumps. Adventitious bud induction and bud number were significantly reduced for one of the tested families when using 400 mg l−1 cefotaxime or timentin. The selection agent kanamycin significantly inhibited growth of embryogenic tissue on filter paper in all the embryogenic lines␣and concentrations tested (20–50 mg l−1). Kanamycin also inhibited growth of embryogenic clumps after two subcultures at 5–50 mg l−1. In␣cotyledons, kanamycin inhibited adventitious bud␣formation in the three seed families used, regardless of the concentrations tested (5–25 mg l−1). There was a significant effect of the seed family on the bud induction and the number of adventitious buds produced. From the results obtained, we propose the use of timentin to eliminate Agrobacterium in transformation experiments, at concentrations of 400 mg l−1 for embryogenic tissues and of 300 mg l−1 for cotyledons. For selection of transformed tissues carrying the kanamycin resistance gene, kanamycin should be used at 20 mg l−1 for embryogenic tissues on filter paper, at 5 mg l−1 when clumps are in direct contact with the selection medium, and bellow 5 mg l−1 for adventitious bud induction. 相似文献
17.
Somatic embryogenesis and further plant regeneration were observed using zygotic embryos, young inflorescences and young leaves
ofEuterpe edulis (Palmae) as explants. Both for the cultures of zygotic embryos and inflorescences, activated charcoal in the medium was essential
for the establishment of viable cultures. Embryogenesis was induced by using a gelled basal medium with MS or Euwens salts
supplemented by high 2, 4-D levels (50–100 mg L−1). The embryogenic process was direct without a callus stage. For further development, cultures with globular or post-globular
embryos were transferred to the basal medium with 2-iP (2.5 mg L−1) and NAA (0.1 mg L−1). To convert embryos to plantlets, cultures were transferred to a third medium in which sucrose and salts were reduced to
the half-strenght of the basal medium, without growth regulators. In the case of liquid medium, with either 2, 4-D or NAA
(10–20 mg L−1). The developmental stage of each explant was critical for the induction of embryogenesis. The histological study of embryogenic
cultures revealed that in the case of zygotic embryos, somatic embryos arise directly from the surface of the cotyledonar
node, or from subepidermal tissues. In the inflorescences, a pro-embryogenic tissue is formed at the floral primordium region;
in the leaves, the first morphogenic event is cell proliferation in the vascular parenchyma. 相似文献
18.
Summary Use of lysozyme was tested for treatment of bacterial contaminations in in vitro shoot cultures of quince (Cydonia oblonga) ‘BA 29’ and the hybrid (Prunus persica × P. amygdalus) rootstock ‘GF 677’. Shoots which had been contaminated for about 1 yr by Bacillus circulans and Sphingomonas paucimobilis were treated in liquid culture, at pH 4.5, with 9–36 mg ml−1 egg white lysozyme (EWL), and compared to each other and to untreated cultures for their growth, proliferation, and number
of bacterial colony-forming units in the tissues. EWL did not negatively affect shoot growth up to 18 mg ml−1; furthermore, the proliferation rates of EWL-treated shoots were sometimes higher than those of controls. In contrast, the
concentration of 36 mg ml−1 had some deleterious effect on the regrowth capacity and shoot production of ‘GF 677’ at the first subculture to solid medium
after EWL, treatments. EWL had a simple bacteriostatic effect against Sphingomonas paucimobilis; in contrast, it was effective at 18 mg ml−1 in eliminating Bacillus circulans in both ‘BA 29’ and ‘GF 677’ cultures, after optimal treatment duration. 相似文献
19.
Low-cost alternatives for the micropropagation of banana 总被引:3,自引:0,他引:3
A 90% resource cost reduction in tissue culture of banana was achieved by replacing tissue culture grade sucrose and Gelrite
in the medium with locally available commercial sugar and a starch/Gelrite mixture and by using sun light instead of artificial
light. The micropropagation of Musa `Grande Naine' by shoot tip culture was used as model. Thirteen commercial sugars from different countries were tested. Best
results were achieved using white and light brown sugars with low electrical conductivity. Sugars of cane or sugar beet origin
were suitable. Starches of corn or potato could partially substitute for Gelrite and agar. In all experiments, micropropagation
rates under natural light conditions were equal to or higher than under the controlled conditions of a growth room with PPFD
of 65 μmol m−2 s−1 and a 16-h photoperiod. Plants were exposed to average PPFD levels of 58–96 μmol m−2 s−1 and photoperiods ranged from 8–16 hours.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.
An efficient somatic embryogenesis system has been established in Catharanthus roseus (L.) G. Don in which primary and secondary embryogenic calluses were developed from hypocotyls and primary cotyledonary somatic
embryos (PCSEs), respectively. Two types of calluses were different in morphology and growth behaviour. Hypocotyl-derived
embryogenic callus (HEC) was friable and fast-growing, while secondary callus derived from PCSE was compact and slow-growing.
HEC differentiated into somatic embryos which proliferated quickly on medium supplemented with NAA (1.0 mg l−1) and BA (1.5 mg l−1). Although differentiation and proliferation of somatic embryos were faster in primary HEC, maturation and germination efficiency
were better in somatic embryos developed from primary cotyledonary somatic embryo-derived secondary embryogenic callus (PCSEC).
At the biochemical level, two somatic embryogenesis systems were different. Both primary and secondary/adventive somatic embryogenesis
and the role of plant growth regulators in two modes of somatic embryo formation have been discussed. 相似文献