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1.
Suxia Cui Wei Wang Chenglie Zhang 《In vitro cellular & developmental biology. Plant》2002,38(4):325-329
Summary Different ecotypes of reed (Phragmites communis Trinius) provide an ideal resource for studies on plant environmental adaptations and presence of genes relating to stress
resistance. Dune reed is a drought-tolerant reed ecotype growing in the desert regions of north-west China. In this work,
in vitro culture systems of dune reed and local swamp reed (as control) were established by optimizing the culture conditions for
each of them. Bright yellow calluses were induced on a Murashige and Skoog medium containing 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D), 5.4 μM naphthaleneacetic acid and 2.2μM benzyladenine. Benzyladenine promoted callus induction, but was not required for callus maintenance. Four types of callus
have been identified from each of the reed ecotypes. Two types of callus, i.e. type A (formed normal green shoots) and type
C (formed albino plants), were both found as embryogenic calluses. The optimal concentrations of 2,4-D to maintain embryogenic
callus were 2.3–4.5 μM for dune reed and 9.0–13.5 μM for swap reed. Plant regeneration was achieved from types A and C callus in a hormone-free medium. The embryogenic calluses
of swamp reed have been maintained for over 2 yr and still retain their strong embryogenic potential; however, those of dune
reed gradually lost their embryogenic potential after only 7 mo. of culture. Regenerated plants from the two reed ecotypes
showed, after a growth season, similar morphology and the same chromosome number (2n=8x=96, octoploid) as the wild plants. 相似文献
2.
Summary Sodium chloride-tolerant plantlets of Dendrocalamus strictus were regenerated successfully from NaCl-tolerant embryogenic callus via somatic embryogenesis. The selection of embryogenic
callus tolerant to 100 mM NaCl was made by exposing the callus to increasing (0–200 mM) concentrations of NaCl in Murashige and Skoog medium having 3% (w/v) sucrose, 0.8% (w/v) agar, 3.0 mg l−1 (13.6 μM) 2,4-dichlorophenoxyacetic acid (2,4-D), and 0.5mg l−1 (2.3μM) kinetin (callus initiation medium). The tolerance of the selected embryogenic callus to 100 mM NaCl was stable through three successive transfers on NaCl-free callus initiation medium. The tolerant embryogenic callus
had high levels of Na+, sugar, free amino acids, and proline but a slight decline was recorded in K+ level. The stable 100 mM NaCl-tolerant embryogenic callus differentiated somatic embryos on maintenance medium [MS medium +3% sucrose +0.8% agar +2.0
mg l−1 (9.0 μM) 2,4-D+0.5 mg l−1 (2.3 μM) kinetin] supplemented with different (0–200 mM) concentrations of NaCl. About 39% of mature somatic embryos tolerant to 100 mM NaCl germinated and converted into plantlets in germination medium [half-strength MS+2% sucrose+0.02 mg l−1 (0.1 μM) α-naphthaleneacetic acid +0.1 mg l−1 (0.49 μM) indole-3-butyric acid] containing 100 mM NaCl. Of these plantlets about 31% established well on transplantation into a garden soil and sand (1:1) mixture containing
0.2% (w/w) NaCl. 相似文献
3.
Embryogenic calli were initiated from embryonic explants of Pinus roxburghii using female gametophytes containing immature pre-cotyledonary embryos. Zygotic embryos were collected at different developmental
stages and cultured on various media. Initiation of embryogenic calli was achieved in pre-cotyledonary zygotic embryos of
a 0.1-mm to 1.2-mm embryonal head on Douglus fir cotyledon revised medium (DCR) medium supplemented with 2,4-D or NAA and
BA. Embryogenic callus development was initiated from the suspensor region of immature embryos. The method of immature embryo
culture was significant as rapid embryogenic callus development occurred in megagametophytes where the suspensor was stretched
onto the medium from the cut micropylar end. Sixty embryogenic lines were established from 2500 explants cultured during one
season. A pro-embryo with six to eight meristematic cells and suspensor of six to ten long, vacuolated cells dominated the
early phase of the callus development. Cleavage polyembryony occurred in proliferating callus, constituting a method of multiplication
of these somatic embryos. Somatic embryos developed to stage-I and stage-II embryos on DCR medium supplemented with 5 μM 2,4-D or 10 μM NAA.
Received: 30 June 1999 / Revision received: 15 November 1999 / Accepted: 3 December 1999 相似文献
4.
Ashok Kumar Sahrawat Suresh Chand 《In vitro cellular & developmental biology. Plant》2001,37(1):55-61
Summary An efficient method was established for high-frequency embryogenic callus induction and plant regeneration from 3-,4-, 5-
and 7-d-old coleoptile segments of Indica rice (Oryza sativa L. cv. Kasturi), Compact and friable callus developed from the cut ends and also on the entire length of the coleoptile segments
cultured on Murashige and Skoog (MS) basal medium (1962) supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D, 4.50–18.0
μM), kinetin (2.32 μM) and sucrose (3%, w/v). High frequency embryogenic callus induction and somatic embryo development was achieved when embryogenic
calluses were transferred to MS medium supplemented with 2.25 μM 2,4-D, 2.32 μM kinetin, 490 μM
L-tryptophan and 3% (w/v) sucrose. Plant regeneration was achieved by transferring clumps of embryogenic callus onto MS medium
containing 2.85 μM indole-3-acetic acid (IAA), 17.77 μM 6-benzylaminopurine (BA) and 3% (w/v) sucrose. Histological observations of embryogenic calluses revealed the presence of
somatic embryos and also plant regeneration via multiple shoot bud formation. Three, 4- and 5-d-old coleoptile segments showed
a significantly (P<0.05) higher frequency of plant regeneration and mean number of plantlets per explant in comparison to 7-d-old coleoptile
segments. The highest frequency (73.5%) of plant regeneration and mean number of plantlets (11.9±1.0) was obtained from 4-d-old
coleoptile segments. Regenerated shoots were rooted on MS basal medium containing 4.92 μM indole-3-butyric acid (IBA) and plants were successfully transferred to soil and grown to maturity. 相似文献
5.
Q. C. Liu H. Zhai Y. Wang D. P. Zhang 《In vitro cellular & developmental biology. Plant》2001,37(5):564-567
Summary Using 15 Chinese and Japanese cultivars of sweetpotato, Ipomoea batatas (L.) Lam., we succeeded in developing an efficient plant regeneration system from embryogenic suspension cultures. The embryogenic
callus derived from shoot apices of the 15 cultivars was used to initiate embryogenic suspension cultures in Murashige and
Skoog (MS) medium containing 9.05 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Rapidly proliferating and well-dispersed embryogenic suspension cultures were established.
Cell aggregates 0.7–1.1 mm in size from embryogenic suspension cultures were transferred to solid MS medium supplemented with
9.05 μM of 2,4-D and formed embryogenic callus with somatic embryos. The embryogenic callus with somatic embryos was further transferred
to MS medium supplemented with 3.78 μM of abscisic acid, resulting in the germination of somatic embryos. Within 20 wk after the initiation, the frequencies of
cell aggregates forming plantlets reached approximately 100% for the 15 tested cultivars. These plantlets, when transferred
to soil, showed 100% survival. No morphological variations were observed. 相似文献
6.
Yuexia Wang Bridget A. Ruemmele Joel M. Chandlee W. Michael Sullivan Jane E. Knapp Albert P. Kausch 《In vitro cellular & developmental biology. Plant》2002,38(5):460-467
Summary Embryogenic callus induction and plant regeneration systems have long been established for creeping bentgrass (Agrostis palustris Huds.), but little research has been reported on optimal medium for embryogenic callus induction and plant regeneration in
velvet bentgrass (Agrostis canina L.), colonial bentgrass (Agrostis capillaries L.), and annual bluegrass (Poa annua L.). The present study compared 14 callus induction media and eight regeneration media for their efficacies on embryogenic
callus induction and plant regeneration in these four species. The embryogenic callus initiation media contained the Murashige
and Skoog inorganic salts and vitamins supplemented with 2,4-dichlorophenoxyacetic acid or 3,6-dichloro-anisic acid and 6-benzyladenine.
l-Proline or casein hydrolyzate was included in some media to stimulate embryogenic callus formation and plant regeneration.
The frequencies of embryogenic callus formation ranged from 0% to 38% and exhibited medium differences within each of the
four species. Callus induction media, plant regeneration media, and genotypes affected plant regeneration rates, which varied
between 0% and 100%. The embryogenic callus induced on Murashige and Skoog medium supplemented with 500 mgl−1 casein hydrolyzate, 6.63 mg l−1 (30 μM) 3,6-dichloro-anisic acid and 0.5–2.0 mg l−1 (2–9 μM) 6-benzyladenine had much higher regeneration rates than those formed on other callus induction media. Embryogenic callus
of annual bluegrass had higher regeneration rates than those of bentgrass species. MSA2D, a media containing 2 mgl−1 (8 μM) 2,4-dichlorophenoxyacetic acid, 100 mgl−1
myo-inositol, and 150 mgl−1 asparagine, was effective in promoting embryogenic callus formation in creeping bentgrass but not in colonial and velvet
bentgrasses and annual bluegrass. 相似文献
7.
Chin-Wen Ho Wei-Ting Jian Hui-Chun Lai 《In vitro cellular & developmental biology. Plant》2006,42(3):240-246
Summary
In vitro seedlings of Lilium × formolongi Hort. evs. Norikula, RaiZen No. 1, RaiZen No. 3, RaiZen Early, and Bailansa were used to induce callus by variously modified
Murashige and Skoog (MS) media, using protocols for flask culture and bioreactor culture. Green embryogenic callus proliferated
from roots near the base of bulblets of five varieties on media containing 0.53–5.3 μM α-naphthaleneacetic acid (NAA), and 28 cell lines were obtained by subcultures on the same medium. For flask culture, the
fresh weight (FW) of embryogenic cell clumps doubled every 4 wk on MS basal salts supplemented with 0.53°M NAA and 30 g l−1 sucrose. The maximum frequency of somatic embryos that developed into plantlets was 76.67±17% when plated onto solid MS basal
medium without plant growth regulators (PGRs). Among the treatments using four types of bioreactors, the best cell growth
and regeneration rate (74±0.14%) of somatic embryos was in a modified 2–1 bioreactor. Cells incubated in the other three bioreactors
furned brown and died. Histological study revealed that regeneration was by somatic embryogenesis. The regenerants showed
normal growth and flowering after 8–9 mo, in the field. A cell line of cv. Norikula has been subcultured in MS basal salts
containing 0.53 μM NAA every 2 mo. for 6 yr. The cell aggregates became more synchronous and many typical embryogenic cells with dense cytoplasm
were observed under a light microscope. The long-term embryogenic cells plated on MS basal medium still gave rise to numerous
somatic embryos and converted into plantlets. 相似文献
8.
Summary A procedure for the regeneration of complete plantlets of Tylophora indica from cultured leaf callus via somatic embryogenesis is described. Callus induction from leaf explants was on Murashige and
Skoog (MS) medium with different concentrations of 2,4-dichlorophenoxyacetic acid (2.4-D; 0.03–3 mg l−1; 0.0–13.56 μM) and kinetin (Kn; 0.01 mg l−1; 0.05 μM). The best response for callus induction was obtained on MS medium containing 2 mg l−1 (9.04 μM) 2.4-D and 0.01 mg l−1 (0.05 μM) Kn. After two subeultures on the same medium the embryogenic callus was transferred to MS medium with different concentrations
of the cytokinin, 6-benzyladenine (0.5–3 mg l−1; 2.22–13.32 μM) and 2-isopentenyladenine (2ip; 0.53 mg l−1; 2.46–14.76 μM) along with 0.01 mg l−1 (0.05 μM) indole-3-butyric acid (IBA) for somatic embryo development and maturation. MS medium with 2 mg l−1 (9.84 μM) 2ip produced the maximum number of mature somatic embryos. The mature embryos were bipolar and on transfer to MS basal medium
produced complete plantlets. After hardening the regenerants were planted in the Gudalur forests of Western Ghats. Total DNA
was extracted from 14 regenerants and the mother plant. Random amplified polymorphic, DNA (RAPD) analysis was carried out
using 20 arbitrary oligonucleotides. The amplification products were monomorphic among all the plants revealing the genetic
homogeneity and true-to-type nature of the regenerants. 相似文献
9.
H. -S. Lin C. van der Toorn K. J. J. M. Raemakers R. G. F. Visser M.J. De Jeu E. Jacobsen 《Plant cell reports》2000,19(5):529-534
Stem segments of seedlings from two Alstroemeria breeding lines, cultured on media supplemented with 4 mg/l 2,4-dichlorophenoxyacetic acid and 0.5–1.0 mg/l 6-benzylaminopurine
(BA), initiated soft callus, which became compact after subculture on a medium with only 0.5 mg/l BA. Friable embryogenic
calli were initiated from compact callus on a medium supplemented with 10 mg/l picloram. Proembryos developed from friable
embryogenic calli via embryos into plants after subculture on medium supplemented with 0.1 mg/l BA. The proembryos formed
friable embryogenic calli again after culture on medium supplemented with 10 mg/l picloram. The total time needed to regenerate
a complete plantlet from friable callus was approximately 6 months. This system for the production of embryogenic material
is considered to have valuable applications for genetic transformation in Alstroemeria.
Received: 22 April 1999 / Revision received: 16 July 1999 · Accepted: 20 July 1999 相似文献
10.
Summary Somatic embryogenesis was induced in callus cultures derived from nucellar tissue of cashewnut (Anacardium occidentale L.). Callus was obtained from nucellar tissue after 3 wk of culture on semisolid Murashige and Skoog (MS) basal medium supplemented
with 2,4-dichlorophenoxyacetic acid (2,4-D, 5 μM)+gibberellic acid (GA3, 15 μM)+N6-benzyladenine (BA, 5 μM). This callus gave rise to an embryogenic mass after 9 wk on maintenance medium containing 2,4-D (10 μM)+GA3 (15 μM)+4% sucrose +0.5% activated charcoal +10% coconut water (CW) +0.05% casein hydrolysate (CH). The embryogenic mass, after
transfer to medium supplemented with 2,4-D (5 μM)+GA3 (30 μM)+4% sucrose +0.5% activated charcoal +10% CW +0.05% CH, gave rise to somatic embryos. The developmental stages of somatic
embryos were observed using light and stereo microscopes. Histological study of somatic embryo development was also carried
out. The present study would be useful for clonal propagation, and variety improvement in cashewnut, which is essential due
to its increasing demand and export potential. 相似文献
11.
Maira Oropeza Ana Karina Marcano Eva De García 《In vitro cellular & developmental biology. Plant》2001,37(2):211-216
Summary Previous results have shown that some proteins secreted in the culture medium are involved with the formation of embryogenic
cells and can modify somatic embryo differentiation. Undifferentiated cell suspensions grown in the presence of 13 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and obtained from embryogenic and non-embryogenic callus were used to study these
events in sugarcane plants (cv.PR-62258). The cell suspension growth curves were determined and soluble proteins were extracted
from embryogenic and non-embryogenic callus and culture medium from cell suspensions. In embryogenic callus we detected 1.43
times more protein than in non-embryogenic callus and the electrophoretic protein patterns show specific polypeptides for
both callus types. In embryogenic callus we detected a cluster of four polypeptides in the range of 38–44 kDa and another
polypeptide of 23 kDa that were not observed in non-embryogenic callus. In nonembryogenic callus there is a 35-kDa polypeptide
that was not detected in embryogenic callus. In the case of extracellular proteins, the medium from embryogenic cell suspensions
contained four polypeptides of 41, 38, 34 and 28 kDa that were slightly detected in the medium from non-embryogenic cell cultures;
we also detected a band at 15 kDa that could not be observed in the medium from non-embryogenic cell suspensions. These results
suggest that the development of embryogenic callus and cell suspensions is related to the type and amount of intracellular
proteins in the callus cells and to the secreted proteins from these cells into the medium. 相似文献
12.
R. Prem Anand A. Ganapathi V. Ramesh Anbazhagan G. Vengadesan N. Selvaraj 《In vitro cellular & developmental biology. Plant》2000,36(6):475-480
Summary Embryogenic callus was induced from primary leaves of Vigna unguiculata (L.) Walp. in MS medium (Murashige and Skoog, 1962) containing 2,4-dichlorophenoxyacetic acid (2,4-D). Greenish-white, friable
embryogenic calluses were used to establish suspension cultures. A shaking speed of 90 rpm and 0.4 ml packed cell volume per
25 ml medium were found to be optimal for maintaining suspension cultures. Globular, heart-shaped and torpedo-shaped embryos
were developed in suspension culture containing 4.52 μM 2,4-D. Maturation of cotyledonary-stage somatic embryos was achieved on 0.05 μM 2,4-D, 5 μM abscisic acid and 3% mannitol. Twenty-two percent of the embryos were converted into plants and survived; survival in the
field was 8–10%. 相似文献
13.
Friable embryogenic callus and somatic embryo formation from cotyledon explants of African marigold (Tagetes erecta L.) 总被引:3,自引:0,他引:3
Embryogenic callus and somatic embryos were induced from cotyledonary explants of African marigold (Tagetes erecta L.). Cotyledons were first cultured on MS medium supplemented with 2.0 mg l–1 2,4-D and 0.2 mg l–1 kinetin. After 5 weeks, calli were transferred to MS medium supplemented with 0.02 mg l–1 thidiazuron where compact embryogenic callus developed. Friable embryogenic callus developed when the compact embryogenic
callus was transferred to medium containing 2,4-D and subcultured every 2 weeks. Friable embryogenic callus has been maintained
for more than 2 years without losing the capacity to generate embryos. Embryo development was obtained when friable embryogenic
callus was transferred to MS medium supplemented with 3 mg l–1 ABA and 60 g l–1 sucrose. The addition of 10–30 mM
l-glutamine improved embryo development.
Received: 13 May 1997 / Revision received: 24 February 1998 / Accepted: 28 March 1998 相似文献
14.
Regeneration of garlic callus as affected by clonal variation, plant growth regulators and culture conditions over time 总被引:3,自引:0,他引:3
A long-term regeneration system for garlic (Allium sativum L.) clones of diverse origin was developed. Callus was initiated on a modified Gamborg's B-5 medium supplemented with 4.5 μM 2,4-D and maintained on the same basal medium with 4.7 μM picloram+0.49 μM 2iP. Regeneration potential of callus after 5, 12 and 16 months on maintenance medium was measured using several plant growth
regulator treatments. The 1.4 μM picloram+13.3 μM BA treatment stimulated the highest rate of shoot production. Regeneration rate decreased as callus age increased, but healthy
plantlets from callus cultures up to 16-months-old were produced for all clones. Regeneration of long-term garlic callus cultures
could be useful for clonal propagation and transformation.
Received: 24 September 1998 / Revision received: 27 January 1999 / Accepted: 26 February 1999 相似文献
15.
M. Gallo-Meagher R. G. English A. Abouzid 《In vitro cellular & developmental biology. Plant》2000,36(1):37-40
Summary Efficient shoot regeneration of sugarcane (Saccharum spp. hybrid cv. CP84-1198) from embryogenic callus cultures has been obtained using thidiazuron (TDZ). Callus was placed
on modified Murashige and Skoog (MS) medium containing 2.3 μM 2,4-dichlorophenoxyacetic acid (2,4-D), or 9.3 μM kinetin and 22.3 μM naphthaleneacetic acid (NAA) and compared with the same MS medium supplemented with 0.5, 1.0, 2.5, 5.0 or 10.0 μMTDZ, A11 TDZ treatments resulted in faster shoot regeneration than the kinetin/NAA treatment, and more shoot production than
either the 2,4-D or kinetin/NAA treatments. Maximum response, as determined by total number of shoots (26 per explant) and
number of shoots greater than 1 cm (4 per explant) 4 wk after initiation, was obtained with 1.0 μM TDZ. The shoots rooted efficiently on MS medium supplemented with 19.7 μM indole-3-butyric acid (IBA). These results indicate that TDZ effectively stimulates sugarcane plant regeneration from embryogenic
callus, and may be suitable to use in genetic transformation studies to enhance regeneration of transgenic plants. 相似文献
16.
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
17.
Summary Embryogenic calluses were induced from 73% of Phalaenopsis shoot-tip explants excised from flower stalk buds by culturing for 7 mo. on New Dogashima Medium (NDM) containing 0.5 μM α-naphthaleneacetic acid (NAA), 4.4 μM 6-benzylaminopurine and 29.2 mM sucrose. The sucrose concentration was increased to 58.4 mM 4 mo. after initiation of the callus culture. These calluses were successfully subcultured as cell suspension cultures in
liquid NDM supplemented with 5.4μM NAA and 58.4 mM sucrose. By simply reducing the sucrose concentration to 29.2 mM, the cells grew into plantlets through a developmental process similar to that of Phalaenopsis seedlings. The occurrence of somaclonal variants was less than 10% in six out of eight genotypes examined. These results
suggest that the embryogenic callus and cell suspension culture could be utilized as the materials for micropropagation and
breeding of Phalaenopsis orchids. 相似文献
18.
Summary We have developed efficient methods for plant regeneration, via both embryogenesis and organogenesis, of Smooth Cayenne pineapple,
Ananas comosus (L.) Merr. Leaf bases and core (stem) sections of in vitro shoots, produced from culture of crown tip meristem, were used as explants for plant regeneration as follows: (1) Leaf base
and core section explants cultured on Murashige and Skoog (MS) medium containing 41 μM 4-amino-3,5,6-trichloropicolinic acid (picloram, P) or thidiazuron (T)/P combinations produced embryogenic tissues. Different
types of embryogenic tissues (friable emryogenic tissue, embryogenic cell cluster, and chunky embryogenic tissue) have been
developed with varying properties in terms of growth rate and state of development. The embryogenic tissues regenerated shoots
upon culture on MS medium containing 13 μM 6-benzylaminopurine (BA) and 1μM α-naphthaleneacetic acid (NAA) followed by culture on MS medium containing 4 μM BA. (2) Crown tip meristems cultured on MS medium containing 13 μM BA followed by leaf explants cultured on MS medium with 27 μM NAA and 1 μM BA produced shoots via direct organogenesis. (3) Explants cultured on MS medium containing 5 μM T and 0.5 μM indole-3-butyric acid (IBA) produced nodular globular structures, which produced shoots upon culture on MS medium containing
1 μM BA and 1 μM gibberellic acid. Shoots obtained from all of the above methods were rooted in half-strength MS medium containing 3 μM NAA and 2.5 μM IBA. Plants were transferred to the greenhouse or shipped to Costa Rica for field trials. Somatic embryo-derived plants exhibited
21 % spininess, and organogenic-derived plants exhibited 5% spininess in the field trials. 相似文献
19.
Alejandrina Robledo-Paz Víctor M. Villalobos-Arámbula Alba E. Jofre-Garfias 《In vitro cellular & developmental biology. Plant》2000,36(5):416-419
Summary Root apices from in vitro cultured garlic (Allium sativum) cloves of cvs. ABEN and GT96-1 were used as axenic explants for organogenic callus production and plant regeneration experiments.
Explants cultured in media based on those of Chu and co-workers (N6) or Murashige and Skoog (MS) could induce organogenic
callus after 8 wk culture in darkness. Both media were supplemented with 2,4-dichlorophenoxyacetic acid (2.2–4.5 μM), alone or combined with 6-furfurylaminopurine (kinetin, 2.3–4.6 μM). Shoots started to grow 3 wk after culturing in the presence of light and the addition to culture media of 4.4 μM N6-benzyladenine. Plants capable of producing microbulbs regenerated 6 wk later. Up to 170 plants g−1 FW callus were obtained when culturing was initiated in MS medium supplemented with 4.6 μM kinetin and 4.5 μM 2,4-dichlorophenoxyacetic acid. 相似文献
20.
Cryopreservation of shoot tips from in vitro plants of sweet potato [Ipomoea batatas (L.) Lam.] by vitrification 总被引:8,自引:0,他引:8
Routine cryopreservation of shoot tips from sweet potato [Ipomoea batatas (L.) Lam] has been hampered by their survival variability after cryogenic exposure. We examined the effects of light conditions
on stock plants, sucrose preculture and cryoprotectant loading on survival after vitrification using PVS2 solution. The survival
of vitrified sweet potato shoot tips cooled to approximately –208 °C was increased by preculturing with 0.3 M sucrose for 24 h at 22 °C. Survival was also enhanced by excising shoot tips immediately after the 8-h dark photoperiod.
The best survival after cryogenic exposure was obtained using 2 M glycerol +0.4 M sucrose for 1 h at 22 °C followed by dehydration with PVS2 for 16 min at 22 °C. Rapid cooling was used and achieved by
the immersion of foil strips into partially solidified nitrogen. Successfully vitrified and warmed shoot tips directly developed
shoots on a medium containing 1 μM NAA, 0.5 μM BA and 0.1 μM kinetin with only minimum callus formation. Shoot formation occurred in all surviving shoot tips. This procedure shows promise
for cryopreserving sweet potato shoot tips.
Received: 2 March 1999 / Revision received: 21 September 1999 / Accepted: 29 September 1999 相似文献