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1.
Waxflowers (Chamelaucium spp.) are native to Australia and now are grown for the cut flower industry worldwide. As part of an effort to achieve somatic
hybridization between the species to improve flower quality, somatic embryogenesis was achieved for Chamelaucium uncinatum and C. repens. Somatic embryos from young leaves of C. uncinatum and C. repens were induced in vitro on Murashige and Skoog (MS) agar medium containing 20 g/l sucrose and 2,4-dichlorophenoxyacetic acid
(2,4-D). For C. uncinatum, up to 4% of explants developed somatic embryos at 20 μM 2,4-D and for C. repens, up to 3% developed somatic embryos at 5 μM 2,4-D. Somatic embryos of C. uncinatum were also induced from immature seeds—a maximum of 6% of seed explants producing somatic embryos on MS medium containing
0.05 μM 6-benzyladenine (BA) and 0.5 μM Naphthalene acetic acid (NAA). Somatic embryo cultures maintained on MS medium supplemented
with 0.1 μM 2,4-D were induced to develop into plantlets after transfer to a hormone-free medium under light. 相似文献
2.
Liliana Marum Joo Loureiro Eleazar Rodriguez Conceio Santos M. Margarida Oliveira Clia Miguel 《Journal of biotechnology》2009,143(4):288-295
An approach combining morphological profiling and flow cytometric analysis was used to assess genetic stability during the several steps of somatic embryogenesis in Pinus pinaster. Embryogenic cell lines of P. pinaster were established from immature zygotic embryos excised from seeds obtained from open-pollinated trees. During the maturation stage, phenotype of somatic embryos was characterized as being either normal or abnormal. Based upon the prevalent morphological traits, different types of abnormal embryos underwent further classification and quantification. Nuclear DNA content of maritime pine using the zygotic embryos was estimated to be 57.04 pg/2C, using propidium iodide flow cytometry. According to the same methodology, no significant differences (P ≤ 0.01) in DNA ploidy were detected among the most frequently observed abnormal phenotypes, embryogenic cell lines, zygotic and normal somatic embryos, and somatic embryogenesis-derived plantlets. Although the differences in DNA ploidy level do not exclude the occurrence of a low level of aneuploidy, the results obtained point to the absence of major changes in ploidy level during the somatic embryogenesis process of this economically important species. Therefore, our primary goal of true-to-typeness was assured at this level. 相似文献
3.
To maintain embryogenic cell lines ofPimpinella brachycarpa, we suspension-cultured friable and rapidly growing yellowish calli in an MS liquid medium containing 0.2 ~ 2,4-D and 0.5pM BAP. Efficient somatic embryogenesis was achieved when selected cells were then transferred to an MS medium (0.2% gelrite)
that contained 0.2gM 2,4-D, 0.5 uM BAP, and 10.0 laM TDZ (thidiazuron). These cells were cultured at 27°C under continuous illumination (21.5
I~E m-2 s-l). Embryogenic calli expanded about four-fold, and developed into pale yellow calli. Somatic embryogenesis was initiated only
from glossy and nodular-type calli. After two more weeks of culture, globular embryos appeared on the surface of calli grown
in the MS medium that contained 10.0 /aM TDZ only, or in combination with 0.5 gM NAA. Experimenting with 2,4-D, an auxin,
to promote embryogenic calli resulted in excessive browning and death. We overcame this problem by growing glossy embryogenic
and nodular calli on media that contained 10.0 gM TDZ. Calli that were not treated with TDZ turned dark brown and were not
viable. Up to 74% of the calli showed somatic embryos when the medium was supplemented with 10.0 uM TDZ and 0.5 uM NAA. Embryos
from these TDZ-induced, somatic embryogenic calli grew efficiently, forming multiple shoots and developing into normal plants.
Therefore, efficient differentiation of suspension-cultured cell clusters into embryogenic calli, along with treatment of
subsequent somatic embryos by TDZ, suggests that TDZ probably helps in establishing the optimum cytokinin-auxin ratio required
for induction and expression of somatic embryogenesis. 相似文献
4.
P. Jha C. B. Yadav V. Anjaiah V. Bhat 《In vitro cellular & developmental biology. Plant》2009,45(2):145-154
An efficient in vitro plant regeneration protocol through somatic embryogenesis and direct shoot organogenesis has been developed for pearl millet
(Pennisetum glaucum). Efficient plant regeneration is a prerequisite for a complete genetic transformation protocol. Shoot tips, immature inflorescences,
and seeds of two genotypes (843B and 7042-DMR) of pearl millet formed callus when cultured on Murashige and Skoog (MS) medium
supplemented with varying levels of 2,4-dichlorophenoxyacetic acid (2,4-D; 4.5, 9, 13.5, and 18 μM). The level of 2,4-D, the
type of explant, and the genotype significantly effected callus induction. Calli from each of the three explant types developed
somatic embryos on MS medium containing 2.22 μM 6-benzyladenine (BA) and either 1.13, 2.25, or 4.5 μM of 2,4-D. Somatic embryos
developed from all three explants and generated shoots on MS medium containing high levels of BA (4.4, 8.8, or 13.2 μM) combined
with 0.56 μM 2,4-D. The calli from the immature inflorescences exhibited the highest percentage of somatic embryogenesis and
shoot regeneration. Moreover, these calli yielded the maximum number of differentiated shoots per callus. An efficient and
direct shoot organogenesis protocol, without a visible, intervening callus stage, was successfully developed from shoot tip
explants of both genotypes of pearl millet. Multiple shoots were induced on MS medium containing either BA or kinetin (4.4,
8.8, 17.6, or 26.4 μM). The number of shoots formed per shoot tip was significantly influenced by the level of cytokinin (BA/kinetin)
and genotype. Maximum rooting was induced in 1/2 strength MS with 0.8% activated charcoal. The regenerated plants were transferred
to soil in pots, where they exhibited normal growth. 相似文献
5.
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
6.
Jing Li Yang Yu Da Niu Chuan Ping Yang Gui Feng Liu Cheng Hao Li 《Plant Cell, Tissue and Organ Culture》2011,106(3):391-399
Somatic embryogenesis (SE) was induced in female flower buds from mature Schisandra chinensis cultivar ‘Hongzhenzhu’. Somatic embryo structures were induced at a low frequency from unopened female flower buds and excised
unopened on Murashige and Skoog (MS) agar medium containing 4.0 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D). Friable embryogenic calli were induced from somatic embryo structures after three
to four subcultures on initiation medium. The frequencies of mature somatic embryo germination and plantlet conversion were
low, but increased in the presence of gibberellic acid (GA3). Some germinated somatic embryos could form friable embryogenic calli on medium without plant growth regulators (PGRs).
The germination and conversion frequencies of somatic embryos from embryogenic calli induced using PGR-free medium were higher
than for somatic embryos from embryogenic calli induced on medium containing 2,4-D. Most somatic embryos from 2,4-D-induced
embryogenic calli had trumpet-shaped embryos, and most somatic embryos from PGR-free medium–induced embryogenic calli had
two or three cotyledons. Histological observation indicated that two- and three-cotyledon embryos had defined shoot primordia,
but most of the trumpet-shaped embryos yielded plantlets that lacked or had poorly developed meristem tissue. Cytological
and random amplification of polymorphic DNA (RAPD) analyses indicated no evidence of genetic variation in the plantlets of
somatic embryo origin. 相似文献
7.
Direct somatic embryogenesis of Frittilaria meleagris L. was induced using leaf base explants excised from in vitro grown shoots. Somatic embryos occurred at the basal part of leaf explants 4 weeks after culture on a Murashige and Skoog
(MS) medium supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) or kinetin (KIN). The highest
number of somatic embryos (SEs) were formed (9.74) from leaf explant on MS medium supplemented with 0.1 mg dm−3 2,4-D after 4 weeks of culture initiation. An initial exposure to a low concentration of KIN in the medium also enhanced
SEs induction. Our observations by light and scanning electron microscopy revealed that SEs originate directly from the epidermal
and subepidermal layers of leaf explant. The developmental stages of somatic embryogenesis from the first unequal cell division
through the meristematic clusters, multi-cellular globular somatic embryos to the fully formed cotyledonary embryos were determined.
After 4 weeks on MS medium without plant growth regulators, SEs developed into bulblets. 相似文献
8.
Nasser J. Y. Sholi Anjana Chaurasia Anuradha Agrawal Neera Bhalla Sarin 《Plant Cell, Tissue and Organ Culture》2009,99(2):133-140
Creamy friable calli were induced from meristems (scalps) of proliferating shoots of plantain (Musa sp.) cv. Spambia (genome AAB) incubated on a semi-solid modified Murashige and Skoog (MS) medium supplemented with 4.5 μM
2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 μM zeatin. About 25% of shoot-tip explants formed scalps, and about 98% of
scalps developed embryogenic calli. Small dense aggregates of cells, were obtained when these calli were transferred to liquid
MS medium supplemented with 4.5 μM 2,4-D and 1.0 μM zeatin. Upon transfer to semi-solid MS medium of the same composition
as described above, aggregates of cells formed somatic embryos. In the presence of 2.5 μM abscisic acid (ABA), maturation
of somatic embryos was 2.6-fold higher than that of control (lacking ABA), and regardless of the type of cytokinin used in
the medium. Upon transfer to MS medium supplemented with 1.25 μM 6-benzyladenine (BA), 80% of germinated embryos developed
into plantlets. 相似文献
9.
Maurecilne Lemes da Silva Daniela Lopes Paim Pinto Miguel Pedro Guerra Eny Iochevet Segal Floh Cláudio Horst Bruckner Wagner Campos Otoni 《Plant Cell, Tissue and Organ Culture》2009,99(1):47-54
The objective of the present work was to induce somatic embryogenesis from zygotic embryos of Passiflora cincinnata Masters. Zygotic embryos formed calli on media with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and
4.5 μM benzyladenine (BA) after 30 days of in vitro culture. A concentration of 18.1 μM 2,4-D resulted in the largest number
of somatic embryos. Embryogenic calli were yellowish and friable, forming whitish proembryogenic masses. Morphologically,
embryogenic cells were small and had large nuclei and dense cytoplasm, whereas non-embryogenic cells were elongated, with
small nuclei and less dense cytoplasm. Calli cultured under white light on basal Murashige and Skoog’s medium with activated
charcoal produced embryos in all developmental stages. There were differences among the treatments, with some leading to the
production of calli with embryos and some only to callus formation. Some abnormalities were associated with somatic embryos,
including fused axes, fused cotyledons and polycotyledonary embryos. Production of secondary somatic embryos occurred in the
first cycle of primary embryo development. Secondary embryos differentiated from the surface of the protodermal layer of primary
embryos with intense cell proliferation, successive mitotic divisions in the initial phase of embryoid development, and a
vascular system formed with no connection to the parental tissue. This secondary embryogenic system of P. cincinnata is characterized by intense proliferation and maintenance of embryogenic competence after successive subcultures. This reproducible
protocol opens new prospects for massive propagation and is an alternative to the current organogenesis-based transformation
protocol. 相似文献
10.
Daniela Lopes Paim Pinto Beatriz de Almeida Barros Lyderson Facio Viccini José Marcello Salabert de Campos Maurecilne Lemes da Silva Wagner Campos Otoni 《Plant Cell, Tissue and Organ Culture》2010,103(1):71-79
In this study, flow cytometric analysis was used to evaluate the genetic stability of Passiflora cincinnata Mast. plants regenerated via primary and secondary somatic embryogenesis. Embryogenic calli obtained from culturing zygotic
embryos on Murashige and Skoog (MS) medium containing 18.1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.4 μM benzyladenine
(BA) were transferred to differentiation medium. Torpedo and cotyledonary embryos were obtained. These primary embryos were
maintained on differentiation medium to generate secondary embryos. Conversion of primary and secondary embryos yielded 305
and 138 normal plants, respectively. Almost 90% of plantlets survived following acclimatization. Flow cytometric analysis
revealed that seed-derived plants had on average 3.01 pg nuclear DNA (2C), and all plants, except for a single plant regenerated
via primary embryogenesis, maintained their ploidy. This single plant contained more than twice the average DNA content: 6.21 pg
(4C). Epidermal stomata of leaves of the tetraploid plant were larger but lower in density than those of diploid plants, indicating
that stomatal characteristics are useful in distinguishing between diploid and tetraploid plants of passion fruit. In summary,
the procedure we employed to regenerated P. cincinnata plants via somatic embryogenesis generated mostly genetically true-to-type plants. 相似文献
11.
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
12.
Xiang Ling You Xiao Tan Jin Ling Dai Yu Hua Li Yong Eui Choi 《Plant Cell, Tissue and Organ Culture》2012,108(2):333-338
An efficient system for inducing somatic embryogenesis in Panax notoginseng was established using shaker flasks and bioreactor cultures; furthermore, regenerated plantlets were successfully transferred
to ex vitro soil conditions. Embryogenic callus was induced from segments of adventitious roots incubated on Murashige and
Skoog (MS) medium containing 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) after 5 weeks of culturing. The highest frequency
(100%) of somatic embryogenesis, with a mean of 32.7 somatic embryos per callus, was obtained on embryogenic callus incubated
on a medium containing 0.5 mg/L 2,4-D. To scale-up somatic embryo formation, 10 g (~1.65 × 104) of early globular-stage somatic embryos were incubated in a 3 L airlift bioreactor containing 1.5 L 1/2 MS medium without
plant growth regulators (PGRs) for a period of 4 weeks; these globular-stage somatic embryos then developed into cotyledonary
embryos. When maintained on PGR-free medium, the cotyledonary embryos developed roots but did not develop shoots. However,
when they were treated with gibberellic acid (GA3), they continued to germinate and transformed into plantlets after 2 weeks of culture. Plantlets with well-developed shoots
and roots were transferred to an autoclaved vermiculite and perlite mixture, acclimatized for a period of 3 months and successfully
transferred to forest mountain soil. Following overwintering, these plants produced new growth. 相似文献
13.
Summary With the aim of the development of a culture method for efficient plant regeneration from barley (Hordeum vulgare L.) protoplasts, we examined several culture conditions for primary calli from immature embryos of cvs. Dissa and Igri, which were used for initiation of cell suspensions. Among the primary callus culture conditions tested, growth condition of donor plants had a great impact on these efficiencies; Igri protoplasts derived from embryos of plants grown in a greenhouse gave rise to albino plants and few green shoots while several cell lines originating from embryos of plants grown in a growth chamber (16h light, 12°C) yielded protoplasts developing into green plants. In contrast, cell suspensions were produced at higher frequencies from calli derived from embryos of greenhouse-grown Dissa plants. In Igri, increased levels of 2,4-dichlorophenoxyaceticacid (2,4-D) significantly reduced the efficiency of cell suspension establishment and plant regeneration from protoplasts was achieved only with suspension cells derived from calli induced at the lowest level (2.5 mg/l), while the effect of the 2,4-D concentration was not clear in Dissa. The developmental stage of immature embryos also affected the efficiency of cell suspension establishment, and the optimal embryo size was determined to be approximately 1mm in diameter. These results demonstrate the importance of callus induction conditions for successful barley protoplast culture. 相似文献
14.
Yu-Ji Lian Xiao-Mei Zhao Guang-Zhe Lin Hak-tae Lim 《Plant Cell, Tissue and Organ Culture》2012,109(3):565-572
Protoplasts were isolated from the young leaves of rapid cycling Brassica rapa and cotyledons and hypocotyls of 10-day-old Brassica juncea seedlings. Protoplasts were fused by 40% polyethylene glycol and cultured in modified K8p medium supplemented with 2.5 mg·l−1 isopentenyladenine (2ip), 0.5 mg·l−1 naphthaleneacetic acid, 1 mg·l−1 2,4-dichlorophenoxyacetic acid (2,4-D), 0.1 mg·l−1 zeatin, 1% dimethyl sulfoxide, and 0.4 M mannitol as osmoticum. After 3 days of initial culture, 3 different culture methods
were employed and evaluated. The highest plating efficiency (1.97%) was obtained with a semi-solid agarose embedding culture
method. Both shoots and somatic embryos formed from protoplast culture-derived calli. The somatic embryos were derived from
asymmetrically divided calli that developed progressively into deep-purple heart shapes as well as the early-torpedo and bipolar
stages to finally form complete plantlets. Thirteen putative somatic hybrids were produced via somatic embryogenesis or organogenesis.
Random amplified polymorphism DNA analysis was performed to identify somatic hybrids. Six regenerated plants had a chromosome
number of 2n = 56 the same as the sum of B. juncea (2n = 36) and B. rapa (2n = 20) chromosomes; 2 plants had a chromosome number of 2n = 54. These regenerated plants exhibited morphology intermediate
to those of their parents. The flowers of somatic hybrids exhibited a range of variation; some were normal, while others were
abnormal. No pollen was produced from regenerated plants. Two plants had crinkled petal-like stamens. 相似文献
15.
After protoplast fusion somatic hybrid calli were obtained by complementation selection between an albino mutant of Datura innoxia and the wildtype of Atropa belladonna (Krumbiegel and Schieder, 1979. Planta 145, 371–375). In the present study experiments are described concerning leaf and shoot induction on several media supplemented with different combinations and concentrations of hormones. Except for fleshy leaves and embryos, no well-formed shoot could be obtained. However, under standard culture conditions after one and a half years, one line produced numerous green shoots, showing a reduced number of chromosomes from Atropa belladonna. The loss of some chromosomes decreased the degree of somatic incompatibility. The additional appearance of shoots with albino sectors, of total albino shoots, and of green shoots showing a different phenotype, demonstrated that the elimination of the chromosomes occurred not only once, but several times. At least one shoot nearly stable in chromosome content and green subline could be obtained possessing only 6 chromosomes of Atropa belladonna and the original chromosome number of Datura innoxia. Experiments were carried out to test the feasibility of producing sexual hybrids through in vivo and in vitro methods by cross pollination. However, no embryos, seeds, or plantlets were obtained, thus demonstrating that protoplast fusion is the only possibility for obtaining hybrids between these two species.Abbreviations BAP
6-benzylaminopurine
- 2,4-D
2,4-dichlor-phenoxyacetic acid
- IAA
indoleacetic acid
- NAA
-naphtaleneacetic acid
- SDS
sodiumdodecylsulfate 相似文献
16.
A. Othmani C. Bayoudh N. Drira M. Marrakchi M. Trifi 《Plant Cell, Tissue and Organ Culture》2009,97(1):71-79
Plant regeneration through somatic embryogenesis from young leaf explants (5–10 mm long) adjacent to the apex of 5–6 year
old offshoots of Tunisian date palm (Phœnix dactylifera L.), cultivar Boufeggous was successfully achieved. Factors affecting embryogenic callus initiation, including plant growth
regulators and explant size, were investigated. The highest induction frequencies of embryogenic calli occurred after 6–7 months
on MS medium supplemented with 10 mg l−1 2,4-D and 0.3 mg l−1 activated charcoal. The subculture of these calli onto maintenance medium resulted in the formation of proembryos. Fine chopping
and partial desiccation (6 and 12 h) of embryogenic calli with proembryos prior to transfer to MS medium supplemented with
1 mg l−1 ABA stimulated the rapid maturation of somatic embryos. Maturated somatic embryo yield per 0.5 g FW of embryogenic callus
was 51 embryos with an average maturation time of 55 days. This was increased to 422 with finely chopped callus, and 124 and
306 embryos following 6 and 12 h desiccation treatments, respectively. The average time to maturation for these 3 treatments
was 35, 43 and 38 days, respectively. Subsequent substitution of ABA in MS medium with 1 mg l−1 NAA resulted in the germination and conversion of 81% of the somatic embryos into plantlets with normal roots and shoots.
The growth of regenerated somatic plants was also monitored in the field. 相似文献
17.
M. A. K. Azad S. Yokota F. Begum N. Yoshizawa 《In vitro cellular & developmental biology. Plant》2009,45(4):441-449
Somatic embryogenesis and subsequent plant regeneration were established from hypocotyl and internode explants collected from
in vitro-grown seedlings and in vitro-proliferated shoots, respectively. Somatic embryogenesis was significantly influenced by the types of auxin and cytokinin.
Friable calluses with somatic embryos developed well in Murashige and Skoog basal (MS) medium supplemented with 0.8–8.8 μM
6-benzylaminopurine (BA) and 2.0–8.0 μM 2,4-dichlorophexoxyacetic acid (2,4-D) or α-naphthaleneacetic acid (NAA). The maximal
frequency of embryogenic callus and somatic embryo formation were obtained when the MS medium was amended with 8.8 μM BA and
4.0 μM 2,4-D. The best embryo germination occurred in a hormone-free 1/2-MS medium. The highest percentage of shoot proliferation
was observed in embryogenic calluses in MS medium containing 2.0 μM BA and 1.0 μM NAA. In vitro-grown shoots were rooted in MS medium with 0.5–2.0 μM indole-3-butyric acid. Regenerants were transferred to vermiculite and
successfully established under an ex vitro environment in garden soil. 相似文献
18.
Perera PI Hocher V Verdeil JL Doulbeau S Yakandawala DM Weerakoon LK 《Plant cell reports》2007,26(1):21-28
Unfertilized ovaries isolated from immature female flowers of coconut (Cocos nucifera L.) were tested as a source of explants for callogenesis and somatic embryogenesis. The correct developmental stage of ovary explants and suitable in vitro culture conditions for consistent callus production were identified. The concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) and activated charcoal was found to be critical for callogenesis. When cultured in a medium containing 100 μM 2,4-D and 0.1% activated charcoal, ovary explants gave rise to 41% callusing. Embryogenic calli were sub-cultured into somatic embryogenesis induction medium containing 5 μM abscisic acid, followed by plant regeneration medium (with 5 μM 6-benzylaminopurine). Many of the somatic embryos formed were complete with shoot and root poles and upon germination they gave rise to normal shoots. However, some abnormal developments were also observed. Flow cytometric analysis revealed that all the calli tested were diploid. Through histological studies, it was possible to study the sequence of the events that take place during somatic embryogenesis including orientation, polarization and elongation of the embryos. 相似文献
19.
G. B. Cabral V. T. C. Carneiro A. L. Lacerda C. B. do Valle A. P. Martinelli D. M. A. Dusi 《Plant Cell, Tissue and Organ Culture》2011,107(2):271-282
Brachiaria brizantha (syn. Urochloa brizantha) is an important tropical forage grass widely cultivated in Brazil. In order to optimize tissue culture conditions for B. brizantha, in vitro culture of mature seeds, basal segments and leaf segments from in vitro plants of an apomictic and a sexual genotype
of B. brizantha was performed. When cultured on different media, leaf segments yielded non-embryogenic calluses which formed several roots.
Friable calluses from mature seeds and basal segments explants incubated on Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic
acid and 6-benzyladenine yielded 80% compact and nodular embryogenic structures. Calluses with such compact embryogenic structures
were highly regenerable upon transfer to medium supplemented with kinetin and naphthalene acetic acid. They produced isolated
somatic embryos, multiple fused scutelli or isolated scutellum with polyembryos that germinated into isolated or multiple
shoots. Green and morphologically normal plants were obtained for the two genotypes. Changing the media from pH 5.8 to pH
4.0 increased the number of explants that formed calluses as well as the number of shoots per explant. When embryogenic calluses
from mature seeds were successively sub-cultured for 4 months, aiming at repetitive somatic embryogenesis, all the regenerated
plants were albinos. The embryogenic nature of the compact structure was confirmed by scanning electron microscopy. 相似文献
20.
Somatic embryogenesis from immature zygotic embryos and monitoring the genetic fidelity of regenerated plants in grapevine 总被引:2,自引:2,他引:0
Somatic embryogenesis and plant regeneration were successfully established on Nitsch and Nitsch (NN) medium from immature
zygotic embryos of six genotypes of grapevine (Vitis vinifera). The optimum hormone combinations were 1.0 mg dm−3 2,4-dichlorophenoxyacetic acid (2,4-D) for callus induction and 1.0 mg dm−3 α-naphthalene acetic acid (NAA) + 0.5 mg dm−3 6-benzyladenine (BA) for embryos production and 0.03 mg dm−3 NAA + 0.5 mg dm−3 BA for embryos conversion and plant regeneration. The frequency of somatic embryogenesis varied from 10.5 to 37.5 % among
six genotypes and 15.5–42.1 % of somatic embryos converted into normal plantlets. The analysis of DNA content determined by
flow cytometry and chromosome counting of the regenerated plantlets clearly indicated that no ploidy changes were induced
during somatic embryogenesis and plant regeneration, the nuclear DNA content and ploidy levels of the regenerated plants were
stable and homogeneous to those of the donor plants. RAPD markers were also used to evaluate the genetic fidelity of plants
regenerated from somatic embryos. All RAPD profiles from regenerated plants were monomorphic and similar to those of the field
grown donor plants. We conclude that somaclonal variation is almost absent in our grapevine plant regeneration system. 相似文献