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1.
Immature and mature zygotic embryos of Paspalum scrobiculatum L. cv. PSC 1 cultured on MS or N6 nutrient medium supplemented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), formed embryogenic callus. Induction of embryogenic callus and subsequent somatic embryogenesis was possible at a lower concentration of 2,4-D on N6 than MS medium. Immature embryos were highly totipotent, forming somatic embryos at a higher frequency than mature embryos. Addition of amino acids (L-proline or L-tryptophan) to 2,4-D medium resulted in significant enhancement of embryogenesis on culture of mature embryos. Silver nitrate also supported an increased frequency of embryogenesis. Thus it is possible to have high frequency of somatic embryogenesis on culture of mature embryos, which are available in abundance and with ease than immature embryos. The somatic embryos readily germinated and formed plantlets on hormone-free regeneration medium. The regenerated plantlets were successful on transfer to soil and set seed. 相似文献
2.
Immature and mature zygotic embryos of hexaploid, Triticale var. DT-46 formed an embryogenic callus, with subsequent somatic embryo formation upon subculture to MS (Murashige and Skoog, 1962) or N6 (Chu et al., 1975) nutrient medium supplemented with various concentrations (9.0–22.5 M) of 2,4-dichlorophenoxyacetic acid (2,4-D). Of the two types of explants, embryogenic tissue from immature embryos responded at a higher frequency, to form somatic embryos over the callus surface. Leaf-base segment cultured on to 2,4-D-containing medium formed a tissue which did not form somatic embryos and instead differentiated into shoot-buds. N6 medium proved to be more effective than MS in support of somatic embryogenesis or shoot-bud formation. Regeneration of plantlets occurred on 2,4-D-free basal medium. These in vitro-formed plantlets were successfully transferred to soil and set seed. 相似文献
3.
Summary Somatic embryos could be induced from embryogenic callus originating from mesocotyl as well as leaf-base segments of Paspalum scrobiculatum on Murashige and Skoog (MS) or Chu et al. (N6) medium supplemented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D; 4.5, 9.0, 18.0, and 22.5 μM). N6 medium was better than MS, for both explants, for high-frequency somatic embryogenesis. Also, mesocotyl tissues were relatively
more totipotent than leaf-base segments. The somatic embryos ‘germinated’ and formed plantlets on transfer of embryogenic
calluses to hormone-free MS or N6 regeneration medium. Embryogenic cultures could be maintained on low hormone medium which readily regenerated to form plantlets
on hormone-free medium. A higher frequency of plantlet formation occurred on MS than on N6 medium. In vitro-formed plantlets were gradually acclimatized in the culture room and on transfer to soil flowered and set seed. Somatic embryogenesis
and plantlet regeneration from mesocotyl and leaf-base segments are potentially simpler systems than regeneration from ‘embryonic’
explants such as immature embryos and unemerged inflorescences. 相似文献
4.
Hypocotyl segments ofEleutherococcus senticosuscultured on Murashigeand Skoog's (MS) medium with 4.5 µM2,4-D produced somaticembryos directly from the surface of explants without interveningcallus formation. When these somatic embryos were subculturedto the same MS medium with 4.5 µM2,4-D, friable embryogeniccalli were formed mainly from radicle tips of somatic embryos,but at a low frequency (5%). Selected embryogenic calli weremaintained on MS agar or liquid medium with 4.5 µM2,4-D.To induce somatic embryo development, embryogenic calli andcell clumps were transferred to MS medium lacking 2,4-D. Thefrequency of somatic embryo formation differed between culturetypes with 1570 embryos formed per Petri dish from callus cultureand 5514 embryos formed per flask from cell suspension cultures.Somatic embryos formed on agar medium had larger cotyledonsthan those of embryos formed in liquid medium. GA3treatmentwas necessary to induce germination from somatic embryos. Therate of plant conversion was 97% in somatic embryos from callusculture and 76% in embryos from liquid culture. Regeneratedplantlets were successfully acclimatized in the glasshouse.Copyright1999 Annals of Botany Company Eleutherococcus senticosus, micro propagation, somatic embryogenesis. 相似文献
5.
We elucidated the relationship between cell proliferation and somatic embryogenesis in the culture of carrot cotyledons. Fresh
weights of the cotyledon expiants were determined every five days while being cultured on a medium containing 2,4-D. Callus
production increased exponentially from Day 20 to Day 25, showing a two-fold rate of proliferation. To examine the embryogenic
potential of the callus, we pre-cultured cotyledon explants on an MS medium with 2,4-D, then transferred them to an MS basal
medium at five-day intervals. Somatic embryos formed most frequently when the cotyledons were pre-cultured for 20 days on
an MS medium that contained 5 μ2,4-D. The frequency of somatic embryo formation was 81%, while that of normal embryos with
two cotyledons was 51% among those formed on a hormone-free medium. We used FACScan analysis to relate the embryogenic potential
of the callus to the S phase in the cell cycle of cultured cells. The S phase was high after 25 days of culture on the medium
with 5 μM 2,4-D. In contrast, the frequency of normal embryogenesis was higher at Day 20 of the pre-culture period. Culturing
embryogenic calli on a medium with 5 μM 2,4-D was most favorable for producing somatic embryos with two cotyledons. We verified
that active somatic embryogenesis was apparently related to cell division activity; somatic embryos induced from actively
dividing cells were apt to accompany cotyledonary abnormality. 相似文献
6.
Plant regeneration through indirect somatic embryogenesis has been established on Holostemma ada-kodien Schult. Type of auxin significantly influenced somatic embryogenesis. Friable callus, developed from leaf, internode and root explants on Murashige and Skoog (MS) medium supplemented with 2,4-D (1.0 mg l–1), was most effective for the induction of somatic embryos. Subculture of the friable callus developed on 2,4-D (1.0 mg l–1) onto solid or liquid 1/2 MS medium with 0.1 or 0.5 mg l 2,4-D turned the callus embryogenic. Suspension cultures were superior to static cultures (solid medium) for the induction of somatic embryos. Transfer of embryogenic callus to liquid 1/2 or 1/4 MS medium with lower levels of 2,4-D (0.05–0.1 mg l–1) induced the highest number of somatic embryos. An average of 40 embryos were obtained from 10 mg callus. Fifty per cent embryos exhibited maturation and conversion upon transfer to 1/10 MS basal solid medium. Plantlets were established in field conditions and 90 per cent survived. 相似文献
7.
Somatic embryogenesis and plant regeneration from suspension cultures of Acanthopanax koreanum Nakai
High-frequency somatic embryogenesis was achieved from an embryogenic cell suspension culture of Acanthopanax koreanum Nakai. Stem segments were cultured on Murashige and Skoog (MS) medium containing auxins and cytokinins. Opaque and friable
embryogenic callus formed on MS medium with 4.5 μm 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.0 μm kinetin or zeatin, but was highest on medium containing 4.5 μm 2,4-D alone. Embryogenic calli were transferred to MS liquid medium containing 4.5 μm 2,4-D and maintained by subculture at 2-week intervals. Initiation of somatic embryogenesis and development up to the globular
stage from embryogenic cell clumps occurred in medium containing 0.45 μm 2,4-D, whereas maturation and germination of somatic embryos occurred in MS medium lacking 2,4-D. Cytokinin treatment suppressed
the normal growth of embryos, but stimulated secondary somatic embryogenesis from the surfaces of primary embryos. Plants
from somatic embryos were acclimatized in a greenhouse.
Received: 14 January 1997 / Revision received: 17 June 1997 / Accepted: 5 July 1997 相似文献
8.
An efficient, highly reproducible system for plant regeneration via somatic embryogenesis was developed for Cenchrus ciliaris genotypes IG-3108 and IG-74. Explants such as seeds, shoot tip segments and immature inflorescences were cultured on Murashige and Skoog (MS) medium supplemented with 2.0–5.0 mg dm?3 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg dm?3 N6-benzyladenine (BA) for induction of callus. Callus could be successfully induced from all the three explants of both the genotypes. But the high frequency of embryogenic callus could be induced only from immature inflorescence explants. Somatic embryos were formed from nodular, hard and compact embryogenic calli when 2,4-D concentration was gradually reduced and BA concentration increased. Histological studies of somatic embryos indicated the presence of shoot apical meristem with leaf primordia. Ultrastructural details of globular and scutellar somatic embryos further validated successful induction and progression of somatic embryogenesis. Shoots were differentiated upon germination of somatic embryos on MS medium containing 2,4-D (0.25 mg dm?3) and BA or kinetin (1–5 mg dm?3). Roots were induced on ½ MS medium containing charcoal (0.8 %), and the regenerated plants transferred to pots and established in the soil showed normal growth and fertility. 相似文献
9.
Summary A protocol was developed for high frequency somatic embryogenesis and plant regeneration from cotyledon and hypocotyl explants
of Eruca sativa. Explants grown on Murashige and Skoog (MS) medium supplemented with 4.52 μM 2,4-D formed embryogenic callus after 4 wk of culture. Secondary somatic embryos were also produced from primary somatic
embryos on MS medium containing 0.56 μM 2,4-D. Somatic embryos developed into mature embryos on MS medium in the presence of 45 gl−1 polyethylene glycol. After desiccation, somatic embryos developed into plantlets by culturing the mature somatic embryos
on 1/2 x MS medium containing 0.24 μM indole-3-butyric acid. 相似文献
10.
Somatic embryos were obtained from immature zygotic embryos of Cedrela fissilis Well. (Meliaceae), after a culture period of 12 months, with regular subcultures every 6–8 weeks. Callus was developed on explants in 2 months
on Murashige and Skoog (MS) medium containing 2,4 dichlorophenoxyacetic acid (2,4-D) or picloram (PIC). When the calli were
transferred to fresh medium, embryogenic tissue appeared on MS + 45 μM 2,4-D, or 22.5 μM 2,4-D + 0.4 μM 6-benzyladenine (BA),
or 20.7 μM PIC after 6 months. Sub-culture of embryogenic tissue in MS medium supplemented with 4.5 μM 2,4-D resulted in the
differentiation into somatic embryos after further 4 months. Repeated secondary somatic embryogenesis was achieved by regular
subculture on this medium. Maturation and conversion of somatic embryos into plantlets was achieved on MS medium without plant
growth regulators and the conversion frequency was approximately 12.5 %. The plantlets were successfully acclimatized in pots
with soil. Histological studies showed that somatic embryos had no detectable connection with the mother explants and that
somatic embryos in advanced stages were bipolar with shoot and root apical meristems, they contained vascular system and showed
typical characteristics of a somatic dicotyledonous embryo. 相似文献
11.
Barbara Stefaniak 《Plant cell reports》1994,13(7):386-389
Summary Friable embryogenic callus and somatic embryos of 4 Gladiolus cultivars were obtained on Murashige and Skoog (MS) medium with various concentration of auxins from the following explants: corm slices, young leaf bases and whole, intact plantlets. Somatic embryos transferred on MS hormone-free medium regenerated into plantlets. All plantlets obtained through embryogenesis did not differ phenotypically from the parental clones. The embryogenic friable callus has been maintained for over 2 years in culture and has retained a very high regeneration capacity.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- KIN
kinetin
- NAA
naphthaleneacetic acid
- MS
Murashige and Skoog Medium (1962)
- E
embryogenic callus
- NE
non-embryogenic callus 相似文献
12.
Summary Indirect somatic embryogenesis, encapsulation, and plant regeneration was achieved with the rare rhoeophytic woody medicinal
plant Rotula aquatica Lour. (Boraginaceae). Friable callus developed from leaf and internode explants on Murashige and Skoog (MS) medium with 0.45 μM 2,4-dichlorophenoxyacetic, acid (2,4-D) was most effective for the induction of somatic embryos. Subculture of the callus
onto half-strength MS medium with the same concentration of 2,4-D resulted in highly embryogenic callus. Suspension culture
was superior to solid medium culture for somatic embryogenesis. Embryogenic callus.during subsequent transfer to suspension
cultures of half-strength MS medium having 0.23 μM 2,4-D induced the highest number of somatic embryos (a mean of 25.6 embryos per 100 mg callus) and the embryos were grown
up to the torpedo stage. Transfer of embryos to half-strength MS basal solid medium allowed development, of 50% of the embryos
to the cotyledonary stage. Of the cotyledonary embryos, 90% underwent conversion to plantlets on the same medium. Encapsulated
cotyledonary embryos exhibited 100% conversion to plantlets. Ninety-five percent of the plantlets established in field conditions
survived, and were morphologically identical to the mother plant. 相似文献
13.
Plant regeneration through indirect somatic embryogenesis was attempted from the immature cotyledon-derived explant of Cassia angustifolia Vahl. — a valuable leguminous shrub. The highest frequency (90.5 %) of somatic embryos was obtained on a Murashige and Skoog (MS) medium augmented with 10.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 μM benzyladenine (BA) with the production of a maximum of 22.8 embryos per explant, of which 35.3 % germinated on the same medium after 6 weeks of culture. A half strength MS medium without plant growth regulators facilitated better conversion of embryos into complete plantlets compared to a full strength MS medium. Regenerated plantlets were successfully acclimatized in sterile Soilrite and transferred to field conditions with a 70 % survival rate. Histological studies performed at different stages of embryogenesis revealed the mode of differentiation of embryos from the callus. The content of chlorophylls (a + b) and carotenoids, and the net photosynthetic rate (PN) in the regenerated plantlets were tested during different periods of acclimatization. 相似文献
14.
M. Kato 《Plant cell reports》1996,15(12):920-923
Immature leaves of in vitro grown shoots of tea were cultured on various levels of 2,4-D. Somatic embryos were induced directly on leaves or via embryogenic callus produced at the basal regions of the leaves. Induction of embryogenesis appeared to be correlated with the maturity of the leaf explants, with younger leaves responding better. The embryogenic response of leaf explants also was correlated with the period of culture in 2,4-D containing liquid medium. Embryogenic calli or repetitive somatic embryos maintained their regeneration capacity for more than 3 years. Histological observation revealed somatic embryos were formed on various regions of the leaf midrib. Somatic embryos germinated and developed into plantlets on agar medium containing BA and IBA.Abbreviations BA
6-benzylaminopurine
- IBA
indole-3-butyricacid
- 2,4-D
2,4-dichloro phenoxyacetic acid 相似文献
15.
Culture conditions for high frequency plant regeneration via somatic embryogenesis in cell suspension cultures of Chelidonium
majus var. asiaticum are described. Immature ovules formed embryogenic calluses at a frequency of 40% when cultured on Murashige
and Skoog (MS) medium supplemented with 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The optimum ovule size for embryogenic
callus formation ranged from 1 to 1.5 mm in length. Cell suspension cultures were established from embryogenic calluses using
MS liquid medium containing 4.52 μM 2,4-D. Upon plating onto MS basal medium, cell aggregates from cell suspension cultures
produced somatic embryos which then developed into plantlets. Regenerated plantlets were transplanted to potting soil and
grown to maturity in a growth chamber.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
Factors Affecting Formation of Somatic Embryos and Embryogenic Callus from Unemerged Inflorescences of a Graminaceous Crop Pennisetum 总被引:1,自引:0,他引:1
Differentiation of somatic embryos was dependent on the concentrationof auxin and the mineral medium. Low levels of auxin 2,4-D inN6 medium, a low ammonium nutrient, favoured the formation ofsomatic embryos, while on MS medium containing high ammoniumcompact tissues appeared. At higher levels of auxin, irrespectiveof nutrient medium, compact tissues were formed. The originof compact tissue on N4 medium could be traced to somatic embryo-likestructures. This tissue regenerated into somatic embryos onhormone-free N6 medium whereas on MS medium thalloid structuresappeared. Pennisetum, unemerged inflorescence, somatic embryo, embryogenic callus 相似文献
17.
We have established a high-frequency plant regeneration system via somatic embryogenesis from mature seeds of creeping bentgrass (Agrostis palustris Huds). The effects of 2,4-dichlorophenoxyacetic acid (2,4-D), 3.6-dichloroo-anisic acid (dicamba) and 6-benzyladenine (BA) on callus formation and embryogenesis were evaluated. Callus produced on the Murashige and Skoog (MS) (1962) medium containing 2,4-D had low embryogenic potency. In the presence of 30 M dicamba, addition of 2.25 to 9 M BA significantly enhanced embryogenic callus formation over dicamba alone. Optimum frequency of somatic embryogenesis was achieved on MS basal medium containing 30 M dicamba and 2.25 M BA. Over 80% of somatic embryos germinated and formed plantlets on half-strength MS basal medium. These plantlets grew normally in the greenhouse.Abbreviations MS
Murashige and Skoog medium
- 2,4-D
2,4-dichlorophenoxyacetic acid
- BA
6-benzyladenine
- dicamba
3, 6-dichloro-o-anisic acid 相似文献
18.
Summary
Kalopanax pictus (Thunb.) Nakai is a tall tree, and its wood has been used in making furniture, while its stem bark is used for medicinal
purposes. Here, we report on the micropropagation of Kalopanax pictus via somatic embryogenesis. Embryogenic callus was induced from immature zygotic embryos. The frequency embryogenic callus
induction is influenced by days of seed harvest. Callus formation was primarily observed along the radicle tips of zygotic
embryos incubated on Murashige and Skoog (MS) medium with 4.4 μM 2,4-dichlorophenoxyacctic acid (2,4-D). Somatic embryogenesis was observed following transfer of embryogenic callus to MS
medium lacking 2,4-D. Somatic embryos at the cotyledonary stage were obtained after 6 wk following culture. Frequency of conversion
of somatic embryos into plantlets was low (35%) on a hormone-free MS basal medium, but it increased to 61% when the medium
was supplemented with 0.05% charcoal. Gibberellic acid (GA3) treatment markedly enhanced the germination frequency of embryos up to 83%. All plantlets obtained showed 98% survival on
moist peat soil (TKS2) artificial soil matrix. About 30 000 Kalopanax pictus plants were propagated via somatic embryogenesis and grown to 3-yr-old plants. These results indicate that production of
woody medicinal Kalopanax pictus plantlets through somatic embryogenesis can be practically applicable for propagation. 相似文献
19.
Summary The plant regeneration ability of callus obtained from zygotic embryos of the monocot Alstroemeria spp. was studied. The best explants for somatic embryogenesis were immature zygotic embryos in half-ovules when the endosperm was still soft and white. For 2 genotypes embryogenic callus was induced on callus induction medium with a success rate of 54%. The best callus induction period was 10 weeks. The morphology of embryogenic callus was nodular. Somatic embryos were formed after transfer of the callus to regeneration medium. These somatic embryos revealed later on the typical features of zygotic Alstroemeria embryos. The total duration of the plant regeneration protocol, from inoculation till rooted plantlets ready for transfer to the greenhouse, was 28 weeks.Abbreviations BAP
6-benzylaminopurine
- 2,4-D
2,4-dichlorophenoxyacetic acid
- MS
Murashige and Skoog (1962)
- NAA
-naphthaleneacetic acid 相似文献
20.
The effect of various concentrations of CuSO4 on the induction and regeneration of embryogenic callus from immature embryos of wheat was investigated. Immature embryos of wheat cvs C-306 and R-3777 were cultured on MS medium supplemented with 2,4-D (11.3 µM) and different levels of cupric sulphate, i.e. 0, 0.1 (MS level), 0.5, 1 and 5 µM. Relatively high induction frequency of callus was obtained on MS medium supplemented with 2,4-D (11.3 µM) and 0.5 µM CuSO4. The compact, nodular, embryogenic callus was maintained on the medium having 2,4-D (11.3 µM) and proline (86.8 µM) by regular subculturing. Plant regeneration from the embryogenic callus occurred on MS medium supplemented with NAA (1.07 µM) and BAP (44.4 µM). Regenerated plantlets were rooted on MSmedium supplemented with IAA (2.85 µM). The average number of regenerated plantlets produced from primary callus induced on 2,4-D (11.3 µM) and 5x CuSO4 was significantly higher. 相似文献