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1.
2.
The present study was undertaken to establish a culture system for ovules excised at the zygote stage in Lilium spp. Ovules of Lilium × `Connecticut King' and L. × `Enchantment' were excised together with placental tissue 3, 5, and 10 days after pollination (DAP) and cultured on B5 medium and half-strength B5 medium containing sucrose at different concentrations. In vitro embryo development in ovules cultured at 3 DAP was influenced by the basal media and the sucrose concentration. The half-strength B5 medium with 9% sucrose was the best condition, but only a few ovules isolated from placental tissue developed into seedlings. Application of embryo culture, in which embryos were excised from ovules after 14 weeks of ovule-with-plancetal-tissue culture, greatly improved the production of seedlings. The present study indicates that a two-step culture procedure, ovule-with-placental-tissue culture and embryo culture, make it possible to produce seedlings from ovules just after fertilization. 相似文献
3.
Host-tissue differences in transformation of pumpkin (Cucurbita pepo L.) by Agrobacterium rhizogenes
Vesna Katavić Sibila Jelaska Tatjana Bakran-Petricioli Chantal David 《Plant Cell, Tissue and Organ Culture》1991,24(1):35-42
Agrobacterium rhizogenes (wild-type strains 8196 and 15834) transformation of pumpkin (Cucurbita pepo L.) intact seedlings grown in vivo, and 6–8-day-old excised cotyledons cultured in axenic conditions was investigated. Transformed (hairy) roots were successfully induced only on the excised cotyledons with the strain 8196, while intact seedlings failed to form hairy roots with either of the two different bacterial strains. Axenic hairy-root cultures established on MS medium without hormones grew vigorously. Mannopine was detected in all transgenic root clones examined. The peroxidase activity in transformed roots was higher compared with normal roots. Electrophoretic analyses of soluble proteins and isoperoxidases showed substantial differences between transformed and normal pumpkin roots. 相似文献
4.
Taeko Tada 《Journal of plant research》1987,100(1):9-16
Seedling establishment of a perennial,Veronicastrum sibiricum ssp.japonicum colonizing at 1,600 m altitude in Nikko National Park was studied for two years. About half of the first-year seedlings died
during the growing season and 45–74 per cent of the seedlings surviving the first summer died during the following winter
season. This winter mortality depended on the end-of-season size of the seedling in the previous autumn and was caused mainly
by the absence of perennation buds. Seedlings which had emerged on bare ground attained larger size and had higher winter
survival than seedlings in a mat of moss. Seedlings germinating in early season attained larger size and had higher probability
of winter survival than seedlings germinating in later season. 相似文献
5.
The N-substituted phthalimide AC 94377 (1-(3-chlorophthalimido)-cyclohexanecarboxamide) was equally effective as a mixture of the gibberellins A4 and A7 (GA4/7) in breaking dormancy and stimulating germination of celery seeds when either was used in combination with ethephon or daminozide as a seed soak. Whereas seedlings emerging from GA4/7-treated seeds became etiolated in comparison with those from untreated seeds, those from AC 94377-treated seeds showed normal development. Preharvest sprays of gibberellic acid (GA3) increased the height of mature plants in comparison with untreated controls by about 16 per cent whereas AC 94377 was ineffective. The yield from GA3-treated plots was about 10 per cent greater than that from AC 94377-treated plots. 相似文献
6.
Sandy alluvial soils in a floodplain supporting a native stand ofCasuarina cunninghamiana Miq. produced about three times as many nodulated seedlings and more than twice as many nodules per nodulated seedling on roots of baitedCasuarina spp. than did clay loam red earth soils from the adjacent valley slope. Moist and well-aerated subsurficial alluvial sands had the greatest nodulation capacity of all the soils sampled. For all topographic positions, soil samples from depths greater than 20 cm promoted 76% more nodulated Casuarina seedlings than samples from the surficial 20 cm.Seedlings of three provenances ofC. cunninghamiana, together with seedlings ofC. glauca Sieb. ex Spreng.,C. cristata F. Muell ex Miq. andC. obesa Miq. developed significantly more nodules per pot and nodules per nodulated seedling in soils from this locale than seedlings of twoCasuarina equisetifolia Forst. provenances. Seedlings of two provenances ofAllocasuarina torulosa (Ait.) L. Johnson had fewer than 1% nodulated seedlings, a significantly lower level by far than that ofCasuarina seedlings.A. torulosa provenances also had significantly fewer nodulated seedlings per pot and nodules per nodulated seedling than all Casuarina hosts excepting one poorly-nodulated provenance ofC. equisetifolia.Nodulated seedlings of allCasuarina species had the capacity to fix atmospheric N2, as indicated by acetylene-reduction capability. The presence of yellow cladodes and low rates of acetylene reduction per plant forC. cristata Miq. suggest that this association was poorly effective. 相似文献
7.
Seabrook Janet E. A. Douglass L. Katheryn Tai George C. C. 《Plant Cell, Tissue and Organ Culture》2001,65(1):69-73
Differences in productivity for somatic embryos (SEs) in vitro among 18 potato cultivars and three wild Solanum species in an earlier study led to the hypothesis that regeneration of SEs may be under genetic control. To examine this
possibility, three test crosses were initiated; Coastal Russet×AF 186-2; Costal Russet×Lenape; AF 186-2×Lenape. True potato
seedlings from these crosses were germinated in vitro. Five stem internode explants from each seedling were excised and cultured on two successive media to promote the formation
of SEs. Seedling explants Costal Russet×AF 186-2 cross produced more SE than the other two crosses, and explants from the
AF 186-2×Lenape cross generally only produced <10 SEs per explant. SEs were produced on the stem-internode explants from the
three crosses at different rates. Data for the number of explants producing SEs and numbers of SEs per explant were highly
significant. Regeneration of SEs is probably under nuclear control and the inheritance for regeneration may be quite straightforward.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
8.
Xiuli Shen William S. Castle Frederick G. GmitterJr 《Plant Cell, Tissue and Organ Culture》2009,97(1):103-108
A suitable protocol for micropropagation of Casuarina hybrid, Casuarina equisetifolia L. × Casuarina glauca Sieber ex Spreng (C. e. × C. g.), was developed. When seeds without seed coats were cultured on 4 germination media, the optimal seed germination percentage
(91%) was obtained on 0.8% agar solidified water medium. Shoot multiplication was achieved by culturing 2-cm long epicotyls,
excised from germinated seedlings, on MS (Murashige and Skoog 1962) basal medium supplemented with BA (6-benzylaminopurine)
at 4.4, 8.8, 17.8 and 35.6 μM. The greatest percentage of axillary bud sproutings (87.5%), mean number of sprouts per explant
(3.8), and shoot length (3.2 cm) were achieved on MS medium supplemented with 17.8 μM BA. MS medium supplemented with 4 different
concentrations of IBA (indole-3-butyric acid) (4.3, 8.7, 13.0 and 17.4 μM) were used for rooting of in vitro grown shoots.
The highest rooting percentage (65.6%), mean number of roots per explant (2.5) and mean length of roots per explant (1.6 cm)
was achieved at 13.0 μM IBA. Rooted shoots grew well after transfer to a substrate of peat and pinebark (7:3) in the greenhouse. 相似文献
9.
Morphogenic responses within the genus Trifolium were investigated by culturing various explants from seedlings of 72 species. Seedlings from 32 species produced callus alone, 40 produced adventitious shoots and/or roots, of which 25 species produced only shoots and 7 species formed only roots. Seedlings within each species also varied in their response to culture. The section of these seedlings most likely to produce adventitious shoots was the original shoot with the remnants of the surrounding hypocotyl and cotyledons, followed by the excised cotyledons themselves.Inter- and intra-varietal variation was observed in T. repens. Genotypes that produced adventitious buds were selected and crossed. An improvement in the proportion of the population capable of morphogenesis was observed in one cultivar. 相似文献
10.
Seeds and seedlings of Manihot utilissima were analysed for cyanogenic glycosides und free amino acids, with special reference to valine and isoleucine which serve as precursors of the aglycone moieties of linamarin and lotaustralin. Seeds contained traces of valine and isoleucine but no glycosides, whereas seedlings contained high concentrations of these amino acids and glycosides. Illumination of seedlings led to a steep increase in the concentration of glycosides followed by a decrease without excretion of detectable HCN. Seeds accumulated asparagine, while seedlings accumulated both asparagine and glutamine in the storage and transport of nitrogen. Seedlings incorporated 13.2 per cent of label from valine-14C(U) and 2.4 per cent of label from isoleucine-14C(U)into linamarin and lotaustralin, respectively. In both cases, appreciable amounts of label were also incorporated into asparagine. 49 per cent of label from H14CN was incorporated inio asparagine in which ca. 98 per cent of total radioactivity was located in the amide-carbon atom. The different patterns of labelling which occurred during the assimilation of H14CN and 14CO2 showed that cyanide metabolism did not proceed via CO2, and that M. utilissima contains an efficient enzyme-system which catalyses the conversion on high concentrations of HCN into asparagine, which subsequently enters different metabolic pools involved with respiration, protein and carbohydrate syntheses. Cyanogenesis in M. utilissima appears lo be directly influenced by available pools of valine and isoleucine, and the metabolism of HCN released from linamarin and lotaustralin by the action of linamarase may be directly related to respiratory and synthetic processes by way of the incorporation of HCN as a unit into asparagine. 相似文献
11.
Rice can acclimate to lethal level of salinity by pretreatment with sublethal level of salinity through osmotic adjustment 总被引:2,自引:0,他引:2
M. Djanaguiraman J. Annie Sheeba Arun K. Shanker D. Durga Devi U. Bangarusamy 《Plant and Soil》2006,284(1-2):363-373
The physiological ability to adapt for various environmental changes is known as acclimation. When exposed to sublethal level
of stress, plants develop the ability to withstand severe stress, as acquired tolerance. The present study was conducted to
explicate the physiological basis of acquired tolerance in rice. Rice seedlings (variety IR 20) were grown in half strength
Hoagland solution, and after 22nd day, they were kept in half strength Hoagland solution containing 50 mM NaCl (sublethal
dose) for 7 days followed by half strength Hoagland solution containing 100 mM NaCl (lethal dose) for another 7 days. The
non-pretreated 29 days old rice seedlings maintained in half strength Hoagland solution were directly transferred to half
strength Hoagland solution containing 100 mM NaCl (lethal dose) solution for 7 days. The control plants were maintained in
half strength Hoagland solution without NaCl. Various morphological and physiological parameters were recorded on 29th and
36th days old seedlings from control, pretreated and non-pretreated plants. The results revealed significant reduction in
growth parameters (shoot length, root length, leaf area and total dry matter production) of non-pretreated plants below that
of pretreated plants. The pretreated plants showed increased values to the extreme of 19.8 per cent in leaf water potential
(ψw), 9 per cent in relative water content (RWC), 26 per cent in photosynthetic rate (P
N), 28 per cent in leaf stomatal conductance, and 47 per cent in chlorophyll a over non-pretreated plants. The same trend was also observed in chlorophyll a/b ratio (6.6%) and F
v/F
m ratio (19.3%). However, a reverse trend was seen in F
o value. The pretreated plants showed improved ionic regulation as evident from low Na+, Cl− and high K+ contents, which is attributed to enhanced plant water status and photosynthesis. Both pretreated and non-pretreated plants
had higher contents of osmolytes viz., sucrose, leaf soluble sugars and proline contents than control plants. However, starch
content revealed an inverse trend. Therefore, the present study reveals that rice can acclimate to lethal dose of salinity
stress by pretreatment with sublethal dose of NaCl.
Section Editor: J. M. Cheeseman 相似文献
12.
Two plant regeneration methods applicable to Leucaenaleucocephala were developed. In the first method, involvingorganogenesis via callus formation, cotyledon, hypocotyl and root segments wereinitiated on MS medium containing different concentrations ofN6-benzyladenine (BA), 2,4-dichlorophenoxyacetic acid (2,4-D), andnaphthaleneacetic acid (NAA). Both compact (type I) and friable (type II) calliwere obtained from the cotyledon and hypocotyl explants treated with differentconcentrations of the growth regulators. Shoots were generated only from thefriable calli formed from the cotyledon explants. The calli formed from thehypocotyl explants did not generate shoots and the root explants died withoutforming callus. Cotyledon explants from 3–4 day old seedlings showedmaximum callus induction compared to those from older seedlings. In a secondmethod involving direct organogenesis, excised cotyledons were cultured on 1/2MS medium containing 10–35 mg l–1N6-benzyladenine (BA) for 7–14 days. Transfer of thecotyledonsto regeneration medium containing low BA resulted in callus formation andsubsequent shoot regeneration from the base of the excised cotyledon explants,with up to 100% frequency. Regenerated shoots rooted best on a basal mediumcontaining no growth regulators. 相似文献
13.
P. E. Onuorah 《Plant and Soil》1973,39(1):187-191
Summary
Pythium aphanidermatum (Edson) Fitzpatrick has been associated with seed decay and severe stem rot of cowpea in Nigeria. The symptoms produced on both seedlings and established cowpea plants are described. Fungus-induced losses of 0.94 per cent as seed decay and 11.10 per cent damage to adult cowpea plants have been recorded. 相似文献
14.
Jonathan D. G. Jones David A. Jones Gerard J. Bishop Kate Harrison Bernard J. Carroll Steven R. Scofield 《Transgenic research》1993,2(2):63-78
Cell-autonomous genes have been used to monitor the excision of both endogenous transposons in maize andAntirrhinum, and transposons introduced into transgenic plants. In tobacco andArabidopsis, the streptomycin phosphotransferase (SPT) gene reveals somatic excision of the maize transposonActivator (Ac) as green sectors on a white background in cotyledons of seedlings germinated in the presence of streptomycin. Cotyledons of tomato seedlings germinated on streptomycin-containing medium do not bleach, suggesting that a different assay for transposon excision in tomato is desirable. We have tested the use of the spectinomycin resistance (SPEC) gene (aadA) and a Basta resistance (BAR) gene (phosphinothricin acetyltransferase, or PAT) for monitoring somatic excision ofAc in tobacco and tomato. Both genetic and molecular studies demonstrate that genotypically variegated individuals that carry clones of cells from whichAc orDs have excised from either SPEC or BAR genes, can be phenotypically completely resistant to the corresponding antibiotic. This demonstrates that these genes act non-cell-autonomously, in contrast to the SPT gene in tobacco. Possible reasons for this difference are discussed. 相似文献
15.
Direct regeneration of shoots and roots through juvenile expiants has been achieved inTribulus terrestris. Cotyledonary leaves along with epicotyl segment from young seedlings were cultured on MS medium containing various concentrations
of auxin with cytokinin and glutamine. A combination of 0.2 mgL−1 NAA, 0.5 mgL−1 BAP and 50 mgL−1 glutamine induced high frequency of shoot and root differentiation in 10 weeks. The callus also could be induced on the above
medium from the cut end of radical segments. Morphogenic response such as per cent shoot and root differentiation was recorded
at regular intervals. 相似文献
16.
Songul Gurel Mehmet Cengiz Baloglu Ekrem Gurel Huseyin Avni Oktem Meral Yucel 《Plant Cell, Tissue and Organ Culture》2011,106(2):261-268
The effects of a two-stage pretreatment of seedlings on the subsequent shoot regeneration capacity were investigated. Pretreated
seedlings were obtained by germinating seeds on three different germination media and then further culturing on six different growth media. Lamina and petiole explants of two sugar beet (Beta
vulgaris L.) breeding lines were then excised from the pretreated seedlings and cultured on five different shoot regeneration media. In both breeding lines, petiole explants produced significantly more shoots than lamina explants with higher frequencies
of organogenic capacities; petiole explants of the lines M1195 and ELK345 produced a mean of 2.1 and 2.7 shoots per explant
while their lamina explants produced 1.5 and 2.2 shoots per explant, respectively. A genotypic variation was evident as the
line ELK345 was more productive for shoot development from both types of explants. In overall comparisons of different germination, growth and regeneration media, germination medium was most effective when supplemented with 0.5 mg/l 6-benzyladenine (BA) while both growth and regeneration
media were most productive when contained a combination of 0.25 mg/l BA and 0.10 mg/l indole-3-butyric acid (IBA). Of all
the treatments tested, the highest mean number of shoots per explant (8.3 shoots) and frequency of organogenic explants (75.6%)
were obtained on regeneration medium supplemented with 0.25 mg/l BA and 0.10 mg/l IBA when petiole explants of the line ELK345
were excised from the seedlings that had been germinated on medium containing 0.5 mg/l BA followed by further growth on medium
containing 0.25 mg/l BA and 0.10 mg/l IBA. 相似文献
17.
Sexual reproduction is important for the growth of populations and the maintenance of genetic diversity. Several steps are involved in the sexual reproduction pathway of plants: the production of flowers, the production of seeds and the establishment of seedlings from seeds. In this paper we quantify the relative importance and spatiotemporal variability of these different steps for four grassland perennials: Centaurea jacea, Cirsium dissectum, Hypochaeris radicata and Succisa pratensis. We compared undisturbed meadows with meadows where the top soil layer had been removed as a restoration measure. Data on the number of flower heads per flowering rosette, the numbers of flowers and seeds per flower head, and the seedling establishment probabilities per seed were collected by field observations and experiments in several sites and years. Combination of these data shows that H. radicata and S. pratensis have higher recruitment rates (1.9 and 3.3 seedlings per year per flowering rosette, respectively) than the more clonal C. dissectum and C. jacea (0.027 and 0.23, respectively). Seedling establishment is the major bottleneck for successful sexual reproduction in all species. Large losses also occurred due to failing seed set in C. dissectum. Comparison of the coefficients of variation per step in space and time revealed that spatiotemporal variability was largest in seedling establishment, followed closely by flower head production and seed set. 相似文献
18.
Summary Cotyledonary node and leaf nodal explants excised from 14-d-old in vitro-grown seedlings of Albizia odoratissima were cultured on a Murashige and Skoog (MS) medium with different concentrations of 6-benzylaminopurine (BAP), N
6-(2-isopentenyl) adenine (2-iP) and kinetin, used either solely or in combinations. The highest frequency for shoot regeneration
(82.5%), the maximum number of shoots per explant (6.9), and the maximum shoot length (2.55 cm) were obtained from cotyledonary
node explants cultured on a MS medium containing 10 μM BAP and 10 μM 2-iP with 30 gl−1 sucrose. Successful rooting was achieved by placing the microshoots on MS medium with 25 μM indole-3-butyric acid (IBA) for 24h first, then transferring to the same medium without IBA. Of the various substrates tested,
vermiculite was best for plant acclimatization, in which 75% of plants survived. 相似文献
19.
Summary Sorghum (Sorghum bicolar (L) Moench cv EA-955 Serena) seeds, subjected or not to hydration-dehydration treatment were planted in distilled water, NaCl, and Na2SO4. When seeds were not hydrated-dehydrated the salts inhibited both seed germination and seedling vigour, and caused an increase in the per cent of abnormal seedlings. The salts neither inhibited seed germination nor increased the per cent of abnormal seedlings if the seeds were treated by hydration-dehydration. However, this treatment was not effective in overcoming the inhibitory effect of either NaCl or Na2SO4 on seedling vigour. Application of these principles in growing plants under saline environment is discussed. 相似文献
20.
Summary
Dendrobium candidum Wall. Ex Lindl. is an important species used in the formulation of Shih-hu, a Chinese traditional medicine. An efficient
protocol for in vitro propagation of D. candidum using the axenic nodal segments of the shoots, originated from the in vitro germinated seedlings, was developed. The seeds from 120-d-old capsules after pollination were first germinated on half-strength
Murashige and Skoog (MS) basal medium supplemented with 30 g l−1 sucrose. After 4 mo., the seedlings were subcultured on a similar medium supplemented with 1 ml l−1 HYPONeX, 80 g l−1 potato homogenate and 2 g l−1 activated charcoal for further growth. Axenic nodal segments excised from 9-mo.-old seedlings were cultured on the medium
in the presence of 2 mg l−1 benzyladenine (BA) and 0.1 mg l−1 naphthaleneacetic acid (NAA). After 75 d, 73.2% of the explants gave rise to buds/shoots. The elongated shoots were rooted
on the medium containing 0.2 mg l−1 NAA and the plantlets were successfully acclimatized in soil. 相似文献