共查询到20条相似文献,搜索用时 187 毫秒
1.
Summary Regeneration of plants via somatic embryogenesis was achieved from zygotic embryo explants isolated from mature seeds of Schisandra chinensis. Merkle and Sommer's medium, fortified with 2,4-dichlorophenoxyacetic acid (2,4-D; 9.04 μM) and zeatin (0.09 μM), was effective for induction of embryogenic callus. The development of a proembryogenic mass and somatic embryos occurred
on Murashige and Skoog medium (MS) free of plant growth regulators. The embryogenic callus induced on Merkle and Sommer's
medium supplemented with 2,4-D (9.04 μM) and zeatin (0.09 μM) showed development of the maximum number of somatic embryos when transferred to MS medium free of plant growth regulators.
The maximum maturation and germination of cotyledonary somatic embryos (46.3%) occurred on MS medium supplemented with 2,4-D
(0.45 μM) and N6-benzyladenine (1.11 μM). The somatic embryo-derived plants were successfully hardned, with a survival rate of approximately 67%, and established
in the field. 相似文献
2.
Summary
In vitro propagation of Andrographis paniculata (Burm. f.) Wallich ex Nees through somatic embryogenesis, and influence of 2,4-dichlorophenoxyacetic acid (2,4-1) on induction, maturation, and
conversion of somatic embryos were investigated. The concentration of 2,4-D in callus induction medium determined the induction,
efficacy of somatic embryogenesis, embryo maturation, and conversion. Friable callus initiated from leaf and internode explants
grown on Murashige and Skoog (MS) medium supplemented with 2.26, 4.52, 6.78, and 9.05μM 2,4-D started to form embryos at 135, 105, 150, and 185d, respectively, after explant establishment. Callus initiated at
13.56μM 2,4-D did not induce embryos even after 240 d, whereas those initiated on MS medium with 4.52μM 2,4-D was most favorable for the formation and maturation of somatic embryos. Callus subcultured on the medium with reduced
concentration of 2,4-D (2.26μM) became embryogenic. This embryogenic callus gave rise to the highest number of embryos (mean of 312 embryos) after being
transferred to half-strength MS basal liquid medium. The embryos were grown only up to the torpedo stage. A higher frequency
of embryos developed from callus initiated on 2.26 or 4.52 μM 2,4-D underwent maturation compared to that initiated on higher concentrations of 2.4-D. The addition of 11.7μM silver nitrate to half-strength MS liquid medium resulted in 71% of embryos undergoing maturation, while 83% of embryos developed
into plantlets after being transferred to agar inedium with 0.44 μMN6-benzyladenine and 1.44 μM gibberellic acid. Most plantlets (88%) survived under field conditions and were morphologically identical to the parent plant. 相似文献
3.
G. Vengadesan N. Selvaraj R. Prem Anand V. Gaba A. Ganapathi 《In vitro cellular & developmental biology. Plant》2005,41(6):789-793
Summary Suspension culture of cucumber (Cucumis sativus L.) has been an inefficient method for production of somatic embryos owing to problems with embryo maturation and conversion.
Embryogenic callus of cv. Green Long was induced on semisolid Murashige and Skoog (MS) medium containing 6.8 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.2 μM 6-benzylaminopurine (BA). A large number of globular somatic embryos were obtained on transfer of the callus to MS liquid
medium supplemented with 87.6 mM sucrose, 1.1 μM 2,4-D, and improved by the addition of 342.4 μM
l-glutamine. MS medium supplemented with 87.6 mM sucrose was more effective in somatic embryo production than other sugars. Subsequent development led to the formation of
heart-and torpedo-shaped embryos. Maturation of somatic embryos occurred on plant growth regulator-free MS semi-solid medium
containing 175.2 mM sucrose and 0.5 gl−1 activated charcoal. Conversion of embryos into plants was achieved on half-strength MS semi-solid medium containing 87.6
mM sucrose and 1.4 μM gibberellic acid (GA3) in a 16h photoperiod. Twenty-seven percent of embryos were converted into normal plants. 相似文献
4.
Summary We report a protocol for somatic embryogenesis and plantlet regeneration of Buchanania lanzan Spreng (Family—Anacardiaceae), which is a tropical fruit tree widely distributed in the dry forests of India. Calluses were initiated from immature zygotic
embryos cultured on Murashige and Skoog (MS) medium supplemented with various combinations of 2,4-dichlorophenoxyacetic acid
(2,4-D), 6-benzyladenine (BA) and/or 1-naphthaleneacetic acid (NAA). The highest frequency (60%) of somatic embryo induction
was obtained in cultures grown on MS medium fortified with 4.53 μM 2,4-D, 5.32 μM NAA and 4.48 μM BA. The medium supplemented with 15 μM abscisic acid (ABA) was most effective for maturation and germination of somatic embryos. This is the first report on somatic
embryogenesis in B. lanzan, which may be helpful for in vitro propagation, ex situ conservation and genetic manipulation of this species. 相似文献
5.
Summary Efficient in vitro propagation of Ceropegia candelabrum L. (Asclepidaceae) through somatic embryogenesis was established. Somatic embryogenesis depended on the type of plant growth
regulators in the callus-inducing medium. Friable callus, developed from leaf and internode explants grown on Murashige and
Skoog (MS) medium supplemented with 4.52μM2,4-dichlorophenoxyacetic acid (2,4-D), underwent somatic embryogenesis. Compared to solid media, suspension culture was superior
and gave rise to a higher number of somatic embryos. Transfer of the friable callus developed on MS medium containing 4.52μM 2,4-D to suspension cultures of half- or quarter-strength MS medium with lower levels of 2,4-D (0.23 or 0.45 μM) induced the highest number of somatic embryos, which developed up to the torpedo stage. Somatic embryogenesis was asynchronous
with the dominance of globular embryos. About 100 mg of callus induced more than 500 embryos. Upon transfer to quarter-strength
MS agar medium without growth regulators, 50% of the somatic embryos underwent maturation and developed into plantlets. Plantlets
acclimatized under field conditions with 90% survival. 相似文献
6.
Summary High-frequency somatic embryogenesis and plant regeneration was achieved on callus derived from leaf (petiole and lamina)
and internode explants of Centella asiatica L. Growth regulators significantly influenced the frequency of somatic embryogenesis and plant regeneration. Calluses developed
on Murashige and Skoog (MS) medium fortified with 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D) or 5.37 μM α-naphthaleneacetic acid (NAA), both with 2.32 μM kinetin (Kn), were superior for somatic embryogenesis. Callus developed on NAA and Kn-supplemented medium favored induction
and maturation of embryos earlier compared to that on 2,4-D and Kn. Embryogenic callus transferred from NAA and Kn-supplemented
medium to suspension cultures of half-strength MS medium with NAA (2.69 μM) and Kn (1.16 μM) developed a mean of 204.3 somatic embryos per 100 mg of callus. Embryogenic callus transferred from 2,4-D and Kn subsequently
to suspension cultures of half-strength MS medium with 2,4-D (0.45 μM) and Kn (1.16 μM) developed a mean of 303.1 embryos per 100 mg of callus. Eighty-eight percent of the embryos underwent maturation and conversion
to plantlets upon transfer to half-strength MS semisolid medium having 0.054 μM NAA with either 0.044 μM BA or 0.046 μM Kn. Embryo-derived plantlets established in field conditions displayed morphological characters identical to those of the
parent plant. 相似文献
7.
Summary Media components used for three stages of development: (1) callus maintenance, (2) maturation of embryos, and (3) conversion
of embryos to plants were shown to affect regeneration of plants for the commercially important red rose cultivar Kardinal.
Embryogenic callus was maintained for 5yr on either Schenk and Hildebrandt’s basal salts medium (SH) supplemented with 13.6
μM 2,4-dichlorophenoxyacetic acid (2,4-D) or Murashige and Skoog’s basal salts medium (MS) supplemented with 18.1 μM dicamba and 0.46 μM kinetin. Maturation of embryos was three times higher using callus maintained on the SH medium supplemented with 2,4-D while
conversion of cotyledonary-stage embryos to plants was significantly higher (10 times) using callus that had been maintained
on MS medium with dicamba and kinetin. Maximum maturation (13.5%), and conversion (15.2%), occurred when callus was cultured
on MS maturation medium without hormones. Cotyledonary-stage embryos cultured on MS conversion medium supplemented with abscisic
acid (5–20 μM) produced plants that survived at a significantly higher rate (two times) in the greenhouse than when embryos were cultured
without abscisic acid. The highest rate of plant regeneration occurred when embryogenic callus of ‘Kardinal’ was maintained
on MS medium supplemented with dicamba and kinetin, maturation of embryos occurred on MS maturation medium without hormones,
and conversion of cotyledonary-stage embryos occurred on MS conversion medium supplemented with abscisic acid. 相似文献
8.
Summary Sugarcane (Saccharum spp. hybrid cv. CP 84-1198) seeds were germinated on modified Murashige and Skoog (MS) basal medium alone or supplemented
with 2.3, 4.5, 11.3, 22.5, and 45.0 μM thidiazuron (TDZ), or 4.5, 13.6, 22.6, and 45.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D), or 4.1, 12.4, 20.7, and 41.3, μM picloram. Both auxins delayed seed germination by approximately 5 d. Maximum germination was observed on MS medium supplemented
with 45.0 μM TDZ. Callus induction occurred for seed germinated on 2,4-D and picloram-containing media, but not on TDZ medium. The greatest
amount of callus (554±198mg per seed) was produced on 4.1 μM picloram. For shoot initiation, calluses were transferred to MS medium alone or supplemented with 2.5 μM TDZ. The highest number of shoots was recorded on TDZ medium from callus that had been obtained originally from media containing
either 4.1 or 12.4 μM picloram or 13.6 μM 2,4-D (∼500). All shoots developed roots and grew to maturity on medium with 24,6 μM indolebutyric acid. 相似文献
9.
Summary The types of auxin in Murashige and Skoog (MS) medium containing N
6-benzyladenine (BA) determined indirect morphogenesis, i.e. development to bipolar somatic embryos or monopolar shoots in
Euphorbia nivulia Buch.-Ham. Indirect in vitro morphogenesis depended on growth regulators, explant excision period, and light. Calli induced from explants collected in
March–April were superior in the induction of indirect morphogenesis to those collected in July–August. Light enforced in vitro morphogenesis, while darkness was inhibitory. The presence of kinetin in the medium also inhibited morphogenesis. Calli developed
on explants collected in March–April grown on MS medium fortified with α-naphthaleneacetic acid (NAA) and BA facilitated indirect
organogenesis, while those developed on medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) and BA underwent somatic
embryogenesis. MS medium with 13.3 μM BA and 2.69 μM NAA was the best for induction of shoots from callus, which developed a mean of 15.7 shoots. Shoots were best rooted on half-strength
MS medium enriched with 2.46 μM indole-3-butyric acid with a mean of 5.1 roots per shoot. MS medium supplemented with 2.26 μM 2,4-D and 4.44 μM BA induced the highest number (mean of 13.4) of somatic embryos. Of the embryos transferred on half-strength MS medium containing
2.89 μM gibberellic acid, 78% of embryos developed to the cotyledonary stage. Most cotyledonary embryos (80%) underwent conversion
to plantlets upon being transferred to half-strength MS basal medium in light. The survival rate of organogenesis and embryo-derived
plants was 80 and 90%, respectively. Calli transformed with Agrobacterium tumefaciens showed expression of the gusA transgene and resistance to kanamycin, but did not undergo morphogenesis. 相似文献
10.
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
11.
P. Giridhar Vinod Kumar G. A. Ravishankar 《In vitro cellular & developmental biology. Plant》2004,40(6):567-571
Summary A novel protocol has been developed for inducing somatic embryogenesis from leaf cultures of Decalepis hamiltonii. Callus was obtained from leaf sections in Murashige and Skoog (MS) medium supplemented with α-naphthaleneacetic acid (NAA)+N6-benzyladenine (BA) or 2,4-dichlorophenoxyacetic acid (2,4-D)+BA. Nodular embryogenic callus developed from the cut end of
explants on media containing 2,4-D and BA, whereas compact callus developed on media containing NAA and BA. Upon subsequent
transfer of explants with primary callus onto MS media containing zeatin and/or gibberellic acid (GA3) and BA, treatment with zeatin (13.68μM) and BA (10.65 μM) resulted in the induction of the highest number of somatic embryos directly from nodular tissue. The maturation of embryos
took place along with the induction on the same medium. Embryogenic calluses with somatic embryos were subcultured onto MS
basal medium supplemented with 4.56μM zeatin+10.65 μM BA. After 4wk, more extensive differentiation of somatic embryos was observed. The mature embryos developed into complete
plantlets on growth regulator-free MS medium. A distinct feature of this study is the induction of somatic embryogenesis from
leaf explants of Decalepis hamiltonii, which has not been reported previously. By using this protocol, complete plantlets could be regenerated through indirect
somatic embryogenesis or organogenesis from leaf explants in 12–16 wk. 相似文献
12.
M. Muruganantham S. Amutha A. Ganapathi 《In vitro cellular & developmental biology. Plant》2010,46(1):34-40
The regeneration of plants via somatic embryogenesis liquid shake culture of embryogenic calluses was achieved in Vigna mungo (L.) Hepper (blackgram). The production of embryogenic callus was induced by seeding primary leaf explants of V. mungo onto Murashige and Skoog (MS) (Physiol Plant 15:473–497, 1962) medium supplemented (optimally) with 1.5 mg/l 2,4-dichloro-phenoxyacetic acid. The embryogenic callus was then transferred
to liquid MS medium supplemented (optimally) with 0.25 mg/l 2,4-dichloro-phenoxyacetic acid. Globular, heart-shaped, and torpedo-shaped
embryos developed in liquid culture. The optimal carbohydrate source for production of somatic embryos was 3% sucrose (compared
to glucose, fructose, and maltose). l-Glutamine (20 mg/l) stimulated the production of all somatic embryo stages significantly. Torpedo-shaped embryos were transferred
to MS (Physiol Plant 15:473–497, 1962) liquid medium containing 0.5 mg/l abscisic acid to induce the maturation of cotyledonary-stage embryos. Cotyledonary-stage
embryos were transferred to 1/2-MS semi-solid basal medium for embryo conversion. Approximately 1–1.5% of the embryos developed
into plants. 相似文献
13.
K. P. Martin A. Shahanaz Beegum C.-L. Zhang A. Slater P. V. Madhusoodanan 《Biologia Plantarum》2007,51(4):769-772
In vitro propagation of an anticancerous drug synthesizing plant, Ophiorrhiza prostrata D. Don, was established through indirect somatic embryogenesis. Friable embryogenic calluses were initiated from O. prostrata leaf and internode explants on Murashige and Skoog (MS) media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) either
alone or in combination with N6-benzyladenine (BA) or kinetin (KIN). Somatic embryos were developed after subculture of the friable calluses onto half strength
MS media containing 0.45 or 2.26 μM 2,4-D alone or in combination with BA or KIN. Medium supplemented with 2.26 μM 2,4-D and
2.22 μM BA was optimal, supporting the production of a mean of 5.8 globular embryos. Subculture of globular embryo-bearing
calluses on half strength MS medium without growth regulators produced the highest embryo frequency, and the majority of them
developing to early torpedo stage. Somatic embryos underwent maturation and converted to plantlets at high frequency (90 %)
on half strength MS medium supplemented with 0.44 μM BA. Somatic embryo-derived plantlets with well-developed roots were established
in field conditions with a 90 % survival rate. 相似文献
14.
Daniela Lopes Paim Pinto Ana Maria Rocha de Almeida Mailson Monteiro Rêgo Maurecilne Lemes da Silva Evelyn Jardim de Oliveira Wagner Campos Otoni 《Plant Cell, Tissue and Organ Culture》2011,107(3):521-530
Mature zygotic embryos of three genotypes of Passiflora edulis Sims, including ‘FB-100’, ‘FB-200’, and ‘FB-300’ were incubated on a Murashige and Skoog (MS) (1962) medium supplemented with different concentrations (18.1–114.8 μM) of 2,4-diclorophenoxyacetic acid (2,4-D) and 4.4 μM of
6-benzyladenine (BA). MS basal medium and MS with BA induced germination of P. edulis embryos. The highest frequencies of embryogenic calli were observed when explants were incubated on MS medium supplemented
with 72.4 μM 2,4-D and 4.4 μM BA for ‘FB-200’, which showed the highest potential for embryogenic callus formation. Cytological
and histological analyses of pro-embryogenic callus revealed two distinct cell types: thin-walled, small, isodiametric cells
with large nuclei and dense cytoplasm, typical of intense metabolic activity; and elongated and vacuolated cells, with small
nuclei and less dense cytoplasm. Differentiation of somatic embryos was promoted on MS medium supplemented with activated
charcoal and indole-3-acetyl-l-aspartic acid (IAA-Asp) either with or without 2,4-D. However, no conversion of somatic embryos into plantlets was observed. 相似文献
15.
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
16.
Veena Agrawal Pratima Rani Sardar 《In vitro cellular & developmental biology. Plant》2007,43(6):585-592
In vitro regeneration through somatic embryogenesis as well as organogenesis using cotyledon of a woody medicinal legume, Cassia angustifolia is reported. The cotyledons dissected from semi-mature seeds, if inoculated on Murashige and Skoog’s medium (MS) supplemented
with auxin alone or in combination with cytokinin, produced direct and indirect somatic embryos. A maximum of 14.36 ± 2.26
somatic embryos per 20 mg of explants including callus were produced in 70% cultures on MS medium with 2.5 μM benzyladenine
(BA) + 10 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Although the percentage of embryogenic cultures was higher (83.33%) at
10 μM 2,4-D + 1 μM BA, the average number of somatic embryos was much less (7.6 ± 0.85) at this level, whereas at 2.5 μM BA
and 5 μM 2,4-D, there was a simultaneous formation of both somatic embryos and shoots. The somatic embryos, although started
germinating on the same medium, developed into full plantlets only if transferred to MS basal with 2% sucrose. Cytokinins
alone did not induce somatic embryogenesis, but formed multiple shoots. Five micromolar BA proved optimum for recurrently
inducing shoots in the competent callus with a maximum average of 12.04 ± 2.10 shoots and shoot length of 2.26 ± 0.03 cm.
Nearly 91.6% shoots (2–2.5 cm in size) organized an average of 5.12 ± 0.58 roots on half strength MS + 10 μM indole-3-butyric
acid. All the plantlets have been transferred successfully to soil. Types of auxin and its interaction with cytokinin significantly
influenced somatic embryogenesis. 相似文献
17.
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
18.
Summary Callus induction was observed from hypocotyl, root, and cotyledonary leaf segments, grown on Murashige and Skoog (MS) medium
supplemented with various concentrations and combinations of 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin (KN). Maximum
callusing (100%) was obtained from root and cotyledonary leaf segments grown on MS medium supplemented with a combination
of 2 mg l−1 (9.1 μM) 2,4-D and 0.2 mg l−1 (0.9 μM) KN. The calluses, when subcultured in the same medium, showed profuse callusing. However, these calluses remained recalcitrant
to regenerate regardless of the quality and combinations of plant growth regulators in the nutrient pool. When hypocotyl segments
were used as explants, callus induction was noticed in 91% of cultures which showed shoot regeneration on MS medium supplemented
with 2 mg l−1 2,4-D and 0.2 mg l−1 KN. These shoots were transferred to fresh medium containing various concentrations and combinations of 6-benzyladenine (BA)
and N6-(2-isopentenyl)adenosine (2-iP). Maximum shoot multiplication was observed after 60 d of the second subculture on MS medium
containing 2 mg l−1 (8.9 μM) BA. These shoots were rooted best (87%) on MS medium containing 2 mg l−1 (9.9 μM) indole-3-butyric acid (IBA). The plantlets were transferred to the field after acclimatization and showed 60% survival. 相似文献
19.
Summary Somatic embryo (bipolar) or shoot (monopolar) morphogenesis in mesophyll cells of Euphorbia nivulia Buch.-Ham in vitro was dependent on the type of auxin supplementing Murashige and Skoog (MS) medium containing benzyladenine. Direct in vitro morphogenesis, i.e., organogenesis, and somatic embryogenesis were significantly influenced by seasonal growth of the donor
plant, explant position (proximal, mid, and distal), and light. Explants collected in march/April were superior to July/August
material. Proximal explants underwent morphogenesis more readily than mid- and tip-derived explants. Incubation in the light
favored morphogenesis while darkness was inhibitory. Kinetin (Kn) was also inhibitory to morphogenesis. MS medium enriched
with different levels of N6-benzyladenine (BA) alone, or in combination with α-naphthaleneacetic acid (NAA) or indole-3-acetic acid (IAA), induced adventitious
shoots directly. Explants collected in March/April cultured on medium with 13.3 μM BA and 2.69 μM NAA developed the highest number of shoots, a mean of 15.2 shoots per proximal explant. Developed shoots rooted the best
on half-strength MS medium with 2.46 μM indole-3-butyric acid, which developed a mean of 5.2 roots per shoot. Rooted healthy shoots could be transplanted to small
pots, with an 80% survival rate. Addition of 2,4-dichlorophenoxyacetic acid (2.4-D) to BA-supplemented medium was obligatory
to develop somatic embryos. MS medium containing 2.26 μM 2,4-D and 4.44 μM BA induced a mean of 44.8 somatic embryos per proximal explant. The embryos passed through distinct stages of embryogenesis,
namely globular, heart, torpedo, and early cotyledonary. The embryos (88%) underwent maturation on half-strength MS medium
with 2.89 μM gibberellic acid (GA3), and its subsequent transfer on half-strength MS basal medium in light conditions facilitated 80% conversion of embryos
to plantlets. Direct shoots or embryos were originated from the mesophyll cells. Somatic embryo development was concurrent
with the independent origin of vasculature in the bulbous basal portion. The survival rate of embryo-derived plants was 90%. 相似文献
20.
A simple and efficient system was developed for rapid somatic embryogenesis from leaf explants of Merwilla plumbea, a traditional but threatened medicinal plant in South Africa. Friable embryogenic callus (FEC) was obtained from leaf explants
on embryogenic callus induction medium containing agar-solidified Murashige and Skoog (MS) salts and vitamins, 8.3 μM picloram,
2.3 μM thidiazuron (TDZ) and 20 μM glutamine. FEC was subsequently incubated in embryogenic callus proliferation medium containing
4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.1 μM picloram for 7 days before it was transferred to liquid somatic embryo
medium (SEML) containing MS medium supplemented with 0.4 μM picloram and 0.9 μM TDZ. In SEML supplemented with 150 mg L−1 haemoglobin, 5.4–35.6 somatic embryos per settled cell volume of 500 mg FEC were obtained. These embryos were at globular
to cotyledonary developmental stages. Embryo maturation, germination and plant formation rate was 94.4% following transfer
of SEs to half-strength MS medium supplemented with 1.4 μM gibberellic acid. Plantlets transferred into soil acclimatized
in the misthouse and established successfully in the greenhouse (100%). This is the first report on induction of Merwilla plumbea somatic embryogenesis. The protocol developed offers controlled vegetative propagation by alleviating extinction threats,
ensures germplasm conservation and provides a system for physiological, biochemical, molecular and cellular studies of embryo
development. 相似文献