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1.
Multiple shoot induction and callus regeneration in Sarcostemma brevistigma Wight & Arnott, a rare medicinal plant 总被引:1,自引:0,他引:1
An efficient micropropagation protocol based on multiple shoot induction and callus regeneration has been standardized in
Sarcostemma brevistigma, a rare medicinal plant. The nodal cuttings were cultured on MS medium supplemented with BA (0.5–8 μM) or Kn (0.5–8 μM) alone
or in combination with NAA (0.5–1.5 μM). Maximum multiple shoot induction was observed on MS medium supplemented with 4 μM
BA. On this medium, 100% cultures responded with an average number of 11.3 shoots per explant. However, the average shoot
length was limited to only 0.9 cm on this medium. The addition of 1 μM NAA along with 4 μM BA gave rise to an average number
of 10.9 shoots with an average shoot length of 1.8 cm. Luxuriantly growing callus was obtained on MS medium supplemented with
BA (5 μM) and 2,4-D (2 μM). The callus was subcultured on MS medium supplemented with BA (2–15 μM) or Kn (2–15 μM) alone or
in combination with NAA (0.5–2 μM) for shoot organogenesis. Optimum callus regeneration was obtained on MS medium supplemented
with 10 μM BA and 1 μM NAA. On this medium, 100% cultures responded with an average number of 13.4 shoots per culture. The
shoots obtained via multiple shoot induction and organogenesis were rooted on half-strength MS medium supplemented with NAA
(1–7 μM) or IBA (1–7 μM). IBA was better than NAA in terms of both the percentage of cultures that responded and the average
number of roots per explant. The rooted shoots were successfully transplanted to soil with 86% success. This standardized
protocol will help to conserve this rare medicinal plant. 相似文献
2.
Plantlet regeneration through shoot formation from young leaf explant-derived callus of Camptotheca acuminata is described. Calli were obtained by placing leaf explants on Woody plant medium (WPM) supplemented with various concentrations
of 6-benzyladenine (BA) and naphthaleneacetic acid (NAA) or 2,4-dichlorophenoxyacetic acid (2,4-D). Callus induction was observed
in all media evaluated. On the shoot induction medium, the callus induced on the WPM medium containing 19.8 μM BA and 5.8
μM NAA was the most effective, providing high shoot regeneration frequency (70.3 %) as well as the highest number of shoots
(11.2 shoots explant−1). The good rooting percentage and root quality (98 %, 5.9 roots shoot−1) were achieved on WPM medium supplemented with 9.6 μM indole-3-butyric acid (IBA). 96 % of the in vitro rooted plantlets with well developed shoots and roots survived transfer to soil. 相似文献
3.
Summary Callus induction and later plant regeneration were studied in four widely grown garlic (Allium sativum L.) cultivars from Europe. Root segments from in vitro plantlets were used as starting material. In addition to cultivar effects, the effects of auxin and cytokinin levels and
the position of the segments on the root were studied. There were no statistically significant differences among cultivars
for the number of root segments that induced callus in the two series of experiments. The average induction frequency was
34.7% in the first series of experiments. Callus induction on apical root segments was significantly higher compared to callus
induction on non-apical root segments in the second series of experiments. Two months after callus induction, callus lines
were transferred to a regeneration medium consisting of Murashige and Skoog basal medium supplemented with 30gl−1 sucrose and 1 mgl−1 (4.6μM) kinetin. Calluses derived from different experiments were quite uniform with respect to their regeneration potential. Also
it was found that our regeneration system was cultivar-independent. The average shoot regeneration frequency was 17.9% in
the first series of experiments. Highly significant differences were found in the frequency of shoot regeneration among different
callus induction treatments. When the cytokinin 6-(γ,γ-dimethylallylamino)purine (0.1mgl−1∶0.5 μM) was present during callus induction, shoot regeneration ranged from 30.10 to 47.60%. Shoot regeneration from callus induced
on non-apical segments was higher, although not significant, compared to callus induction from apical root segments in the
second series of experiments. All in all, an efficient callus induction and plant regeneration system was developed from both
apical and non-apical segments taken along the entire length of the roots. This system has potential to be used for garlic
transformation. 相似文献
4.
Azza A. Tawfik Mohamed F. Mohamed 《In vitro cellular & developmental biology. Plant》2007,43(1):21-27
Nodular meristematic callus was induced on the basal cut surface of apical shoot explants of salvia cultured on Murashige
and Skoog (MS) medium supplemented with 4.5, 13.5, or 22.5 μM thidiazuron (TDZ). Cultures were incubated in the dark for 1 wk
and then transferred to light conditions for 4 wk. A higher percentage of explants developing callus was observed on medium
containing either 4.5 or 13.5 μM TDZ, although explants on 4.5 μM developed larger calluses. The callus was maintained on
medium containing 4.5 μM TDZ and 0.45 mM ascorbic acid. Shoot differentiation, after each of three successive maintenance
passages, was induced from callus grown on medium containing either 4.4 or 8.8 μM benzyladenine (BA). A greater number of
shoots were harvested from callus differentiated on BA (4.4 or 8.8 μM) medium with 0.45 mM ascorbic acid added. Shoots developed
roots on MS medium supplemented with 4.9 μM of indole-3-butyric acid. The addition of ascorbic acid to the shoot differentiation
medium enhanced rooting, number of roots per shoot, and survival rate. Approximately 75% in vitro plantlets were acclimatized to ex vitro conditions. Histological investigations confirmed both adventitious meristem initiation during the callus induction phase,
and subsequent organogenic shoot development on the differentiation medium. The novel protocol for the meristematic callus
induction and plant regeneration in this study may be useful for biotechnological applications for salvia improvement via
genetic transformation or mutagenesis and in vitro propagation approaches. 相似文献
5.
This report deals with micropropagation of the critically endangered and endemic Turkish shrub, Thermopsis turcica using callus, root and cotyledonary explants. Callus cultures were initiated from root and cotyledon explants on MS medium
supplemented with 0.5–20 μM NAA or 2,4-D. The root explants were found to be better in terms of quick responding and callusing
percentages as compared to the cotyledons. Organogenic callus production with adventitious roots and shoots were obtained
on MS medium with only NAA. The calli obtained with NAA, root and cotyledonary explants were cultured with BA and kinetin
(2–8 μM) alone or in combination with a low level (0.5 μM) of 2,4-D or NAA. The best regeneration of shoots from root explants
was observed on hormone-free MS medium. NAA with BA or kinetin in the medium improved shoot induction from the calli obtained
with NAA. Maximum percentage of shoots (93.3%), maximum number of shoots (6.2) and maximun length of shoots (8.22 cm) were
achieved from cotyledonary explants at 4 μM BA and 0.5 μM NAA. The presence of 0.5 μM or higher levels of 2,4-D in shoot induction
medium inhibited the regeneration in T. turcica explants. 83% of in vitro rooting was attained on pulsed-IBA treated shoots. The regenerated plants with well developed shoots and roots were successfully
acclimatized. Application of this study’s results has the potential to conserve T. turcica from extinction. 相似文献
6.
M. J. Prado M. V. Gonzalez S. Romo M. T. Herrera 《Plant Cell, Tissue and Organ Culture》2007,88(1):1-10
The present work reports on a study of plant regeneration carried out with callus from the leaf blades and petioles of field-grown
male adult kiwifruit plants (Actinidia deliciosa (Chev.) Liang and Ferguson). The cultivars used were ‘Tomuri’ and clone A, a selected male plant grown in north western Spain.
The best shoot induction conditions were obtained in ‘Tomuri’ leaf blades cultured in K(h) medium in the presence of 23 μM
Zeatin and 0.1 μM NAA. Under these conditions, more than 80% of organogenic callus induction was observed, with an average
of 14 new shoots in the second subculture. The initial length of the shoots affected shoot elongation, which was accomplished
by culturing isolated shoots in K(h) medium with half-strength salts, supplemented with 0.4 μM Zeatin and 0.1 μM NAA. A possible
detrimental long-term effect of cytokinins on shoot elongation can account for the results, since elongation was not observed
until 1 month of culture in elongation medium. For rooting, shoots (1 cm in length) were basally immersed in a 5 mM IBA solution
for 15 s, and transferred to half-strength K(h) basal medium. Regenerated plants were acclimated in a sterile peat:perlite
substrate for 10 days, and then transferred to soil. AFLP analysis was accomplished with 15 primer combinations from which
13 showed reproducible and well-resolved bands, producing a total of 1321 fragments from which 1281 were polymorphic (97%).
A dendrogram was constructed using both monomorphic and polymorphic bands, showing genetic variation among field-grown plants
and tissue culture-derived regenerants. 相似文献
7.
R. V. Sairam C. Wilber J. Franklin B. Smith J. Bazil R. Hassel D. Whaling K. Frutiger C. A. Blakey R. Vierling S. L. Goldman 《In vitro cellular & developmental biology. Plant》2002,38(5):435-440
Summary A protocol for high-frequency callus, somatic embryogenesis, and plant regeneration for Tripsacum is described. Plants were regenerated from complete shoot meristems (3–4 mm) via organogenesis and embryogenesis. In organogenesis,
the shoot meristems were cultured directly on a high cytokinin medium comprising 5–10 mgl−1 (22.2–44.4 μM) 6-benzyladenine (BA). The number of multiple shoots varied from six to eight from each meristem. The time required for production
of plants from organogenesis was rapid (4–6 wk). In contrast, callus was induced on an auxin medium and continuously cultured
on an auxin medium for production of somatic embryos. Prolific callus with numerous somatic embryos developed within 3–4 wk
when cultured on an auxin medium containing 5 mgl−1 (22.6μM), 2,4-dichlorophenoxyacetic acid (2,4-D). The number of shoots induced varied from two to five per callus. Regardless of
the cultivars used, the frequency of callus induction and plant regeneration was between 48% and 94%. The seed germination
procedures also were modified and resulted in a maximum of 60–80% seed germination. Finally, the rate of T-DNA transfer to
complete shoot meristems of Tripsacum was high on the auxin medium and was independent of whether super-virulent strains of Agrobacterium were used or not. 相似文献
8.
Factors influencing reliable shoot regeneration from leaf explants of rapeseed (Brassica napus L.) were examined. Addition of AgNO3 to callus induction medium was significantly effective for shoot regeneration in all three genotypes initially tested. When
48 genotypes subsequently were surveyed, a large variation of shoot regenerability was observed, ranging from 100 to 0% in
frequency of bud formation and from 7.5 to 0 in the number of buds per explant. A significant correlation (r=0.84) was observed between the frequency of bud formation and the number of buds per explant. The shoot regenerability from
leaf explants was not related to that from cotyledonary explants (r=0.28). Histological observations showed that an organized structure developed from calluses produced at vascular bundle tissues
after 7 days of culture on callus induction medium, and they developed shoot apical meristems one week after transfer onto
shoot induction medium. Regenerated plantlets were obtained 2 months after the initiation of culture and they normally flowered
and set seeds. No alterations of morphology or DNA contents were observed in regenerated plants and their S1 progenies. 相似文献
9.
A. García-Luis R.V. Molina V. Varona S. Castelló J.L. Guardiola 《Plant Cell, Tissue and Organ Culture》2006,85(2):137-144
The effect of orientation as regards to gravity, and that of contact with the medium of culture, on shoot regeneration at the cut edges of epicotyl explants of Troyer citrange (Citrus sinensis (L.) Osbeck×Poncirus trifoliata (L.) Raf.) have been separated. The shoot regeneration pathway was not affected by the orientation of the explants as regards to gravity, and was determined by explant polarity and the contact with the culture medium. At the apical edge of the explants, the contact with the medium shifted the pathway of shoot regeneration from a direct one to an indirect one, with formation of a callus. This callus formation was cytokinin-dependent, but the change in the pathway of organogenesis was not caused by the increase in cytokinin availability resulting from the contact with the medium. In contact with the media, regeneration at the basal edge of the explants occurred through an indirect pathway after callus formation. No regeneration occurred, at the basal edge, if the contact with the media was prevented. The orientation of the explants as regards to gravity affected shoot formation through the direct pathway of organogenesis. The number of buds differentiated, and that of growing shoots increased when the orientation of the explants departed from the vertical upright position. 相似文献
10.
Summary
Tylophora indica (Burm. f.) Merrill is a threatened medicinal climber distributed in the forests of northern and peninsular India. An efficient
and reproducible protocol for high-frequency callus regeneration from immature leaf explants of T. indica was developed. Organogenic callus formation from immature leaf pieces was obtained by using Murashige and Skoog (MS) medium
supplemented with 7 μM 2,4-dichlorophenoxyacetic acid and 1.5 μM 6-benzyladenine. On this medium 92% explants produced callus. The optimal hormone combination for plantlet regeneration was
8 μM thidiazuron, at which shoot regeneration was obtained from 100% of the cultures, with an average of 66.7 shoots per culture.
Histological studies of the regenerative callus revealed that shoot buds were originated from the outermost regions. For root
formation, half-strength MS medium supplemented with 3 μM indole-3-butyric acid was used. Plants were transferred to soil, where 92% survived after 3 mo. of acclimatization. 相似文献
11.
High frequency somatic embryogenesis and plant regeneration from zygotic embryo-derived callus cultures of three Allium species 总被引:1,自引:0,他引:1
P. van der Valk O. E. Scholten F. Verstappen R. C. Jansen J. J. M. Dons 《Plant Cell, Tissue and Organ Culture》1992,30(3):181-191
The plant regeneration ability of zygotic embryo-derived callus cultures was studied for 12 A. cepa varieties and accessions, two A. fistulosum varieties, one A. fistulosum x A. cepa interspecific hybrid and two A. porrum varieties. Compact embryogenic callus was induced on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid. The embryogenic calluses of all three Allium species were similar in appearance. For all accessions tested plants could be regenerated at a high frequency from this compact callus through somatic embryogenesis, when using kinetin supplemented MS medium (regeneration medium). Addition of abscisic acid to the regeneration medium stimulated the formation of both somatic embryos and shoots for a number of varieties. Concerning shoot regeneration from callus cultures, significant differences existed between genotypes of all accessions except one.Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- VDH
Van Der Have Seed company 相似文献
12.
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
13.
An effective and reproducible protocol for the micropropagation ofKigelia pinnata L through high frequency callus regeneration is described. Seeds were surface sterilized before culturing on Gamborgs basal
medium (B5 medium). After two weeks the cotyledonary node along with a portion of the hypocotyl were carefully excised from
well-developed embryos and subcultured on B5 medium supplemented with different concentrations of 2,4-D and BAR The cultured
cotyledonary node expiants showed callus formation at the base of the lower cut end of the hypocotyl. This callus showed shoot
initiation after two weeks of subculture on the regeneration medium supplemented with various concentrations of BAP alone
or in combination with NAA. The highest number of shoot regeneration occurred on medium containing 5 γM BAP and 0.1 γM NAA.
The optimum rooting of the regenerated shoots was observed on 1/2B5 medium supplemented with 4 γM IBA. Micropropagated plants
were successfully established in soil in field condition with a survival frequency of 100%. 相似文献
14.
A short-term regeneration system from leaf-base-derived callus of wheat (Triticum aestivum L.) was developed. Embryogenic callus formation and shoot regeneration were achieved from the first basal segments of 3–4-day-old seedlings. Callus formation frequency as well as plantlet regeneration frequency was dependent on the composition of basal medium and the concentration of 2,4-dichlorophenoxyacetic acid (2,4-D). MS medium with 2,4-D 4.5–9.0 mol l–1 was optimal for the culture of wheat leaf base. Effects of different combinations of plant growth regulators, which were added in either callus induction medium or shoot regeneration medium, were tested. Adding of BAP in callus induction medium shortened the time of shoot emergence but could not improve the producing of embryogenic calli and green plantlets. Optimal ratio of 2,4-D, BAP and NAA gave similar regeneration frequency to control. Existence of cytokinins in regeneration medium had no effect on increasing the regeneration frequency. The regenerants could grow to normal, fertile plants after they were transferred into soil. 相似文献
15.
Doubled haploid (DH) genotypes from a genetic mapping population of Brassica oleracea were screened for ease of transformation. Candidate genotypes were selected based on prior knowledge of three phenotypic markers: susceptibility to Agrobacterium tumefaciens, shoot regeneration potential and mode of shoot regeneration. Mode of regeneration was found to be the most significant of the three factors. Transgenic plants were successfully obtained from genotypes that regenerated multiple shoots via a distinct swelling or callus phase. The absence of tissue culture blackening (associated with genotypes that formed callus) was found to be critical for transformation success. Transgenic shoots were obtained from genotypes that regenerated via an indirect callus mode, even when susceptibility to Agrobacterium was low. The most efficient genotype (DH AG1012) produced transgenic shoots at an average rate of 15% (percentage of inoculated explants giving rise to transgenic plants). The speed and efficiency of regeneration enabled the isolation of transgenic shoots 5–6 weeks after inoculation with A. tumefaciens. This line was also self-compatible, enabling the production of seed without the need for hand-pollination. A genetically uniform DH genotype, with an associated genetic map, make DH AG1012 highly desirable as a potential model B. oleracea genotype for studying gene function. The possibility of applying the same phenotypic tissue culture markers to other Brassica species is discussed. 相似文献
16.
K. Chengalrayan M. Gallo-Meagher 《In vitro cellular & developmental biology. Plant》2001,37(4):434-439
Summary Sugarcane (Saccharum spp. hybrid cv. CP 84-1198) embryogenic calluses were induced from young leaves cultured on modified Murashige and Skoog
basal medium supplemented with 13.6 μM 2,4-dichlorophenoxyacetic acid. Five concentrations, 0.5, 1.0, 2.5, 5.0, and 10.0 μM, of five different growth regulators, 6-benzylaminopurine, kinetin, 6-γ,γ-(dimethylallylamino)purine, zeatin, and thidiazuron,
were tested with or without 22.5 μM α-naphthaleneacetic acid to compare their ability to induce regeneration from embryogenic callus. After 4 wk on medium, the
percentage of shoot meristem induction was evaluated, and after 10 wk the total number of shoots produced, as well as the
percentage of shoots greater than 1 cm in length, was obtained. Although it had the lowest percentage of elongated shoots,
medium containing thidiazuron alone performed better than all other growth regulators tested, with the highest percentage
of shoot induction and the largest number of shoots, particularly at a concentration of 2.5 μM. 相似文献
17.
Hai Ping Hong Hongyi Zhang Paula Olhoft Steve Hill Hunt Wiley Effie Toren Helke Hillebrand Todd Jones Ming Cheng 《In vitro cellular & developmental biology. Plant》2007,43(6):558-568
A regeneration and transformation system has been developed using organogenic calluses derived from soybean axillary nodes
as the starting explants. Leaf-node or cotyledonary-node explants were prepared from 7 to 8-d-old seedlings. Callus was induced
on medium containing either Murashige and Skoog (MS) salts or modified Finer and Nagasawa (FNL) salts and B5 vitamins with
various concentrations of benzylamino purine (BA) and thidiazuron (TDZ). The combination of BA and TDZ had a synergistic effect
on callus induction. Shoot differentiation from the callus occurred once the callus was transferred to medium containing a
low concentration of BA. Subsequently, shoots were elongated on medium containing indole-3-acetic acid (IAA), zeatin riboside,
and gibberellic acid (GA). Plant regeneration from callus occurred 90 ∼ 120 d after the callus was cultured on shoot induction
medium. Both the primary callus and the proliferated callus were used as explants for Agrobacterium-mediated transformation. The calluses were inoculated with A. tumefaciens harboring a binary vector with the bar gene as the selectable marker gene and the gusINT gene for GUS expression. Usually 60–100% of the callus showed transient GUS expression 5 d after inoculation. Infected
calluses were then selected on media amended with various concentrations of glufosinate. Transgenic soybean plants have been
regenerated and established in the greenhouse. GUS expression was exhibited in various tissues and plant organs, including
leaf, stem, and roots. Southern and T1 plant segregation analysis of transgenic events showed that transgenes were integrated into the soybean genome with a copy
number ranging from 1–5 copies. 相似文献
18.
Summary Development of an efficient transformation method for recalcitrant crops such as sugar beet (Beta vulgaris L.) depends on identification of germplasm with relatively high regeneration potential. Individual plants of seven sugar
beet breeding lines were screened for their ability to form adventitious shoots on leaf disk callus. Disks were excised from
the first pair of true leaves of 3-wk-old seedlings or from partially expanded leaves of 8-mo.-old plants and cultured on
medium with 4.4 μM 6-benzylaminopurine for 10 wk. At 5 wk of culture, friable calluses and adventitious shoots began to develop. Rates of callus
and shoot formation varied between breeding lines and between individual plants of the same line. Line FC607 exhibited the
highest percentage (61%) of plants that regenerated shoots on explants. Among the plants with a positive shoot regeneration
response, line FC607 also had the highest mean number (8.3±1.1) of shoots per explant. Individual plants within each line
exhibited a wide range of percentages of explants that regenerated shoots. A similar variation was observed in the number
of shoots that regenerated per explant of an individual plant. No loss of regeneration potential was observed on selected
plants maintained in the greenhouse for 3 yr. Regenerated plants exhibited normal phenotypes and regeneration abilities comparable
to the respective source plants. Based on our results, it is imperative to screen a large number of individual plants within
sugar beet breeding lines in order to identify the high regenerators for use in molecular breeding and improvement programs. 相似文献
19.
Manickam V.S. Elango Mathavan R. Antonisamy R. 《Plant Cell, Tissue and Organ Culture》2000,62(3):181-185
The development of stem callus mediated plant regeneration system for Withania somnifera is described. Maximum callus proliferation was obtained on Murashige and Skoog medium supplemented with 2.26 μM 2,4-D. Three-week-old,
white, friable callus was used for shoot regeneration. The maximum shoot regeneration (6.2 ± 0.34 shoots/explant) was achieved
in four weeks when callus was cultured on MS medium fortified with 4.44 μM BA and 0.57 μM IAA. Regenerated shoots were excised
and multiplied (8.4 ± 0.43 shoots/explant) on MS medium supplemented with 4.44 μM of BA. Multiple shoots were divided into
single shoots and were rooted (5.1 ± 0.49 rootlets/shoot) on half strength MS medium supplemented with 9.84 μM of IBA. After
a hardening phase of 3 weeks the plantlets were transferred to the field.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.
Effects of growth regulators and incubation period on in vitro regeneration of adventitious shoots from gerbera petioles 总被引:4,自引:0,他引:4
Orlikowska Teresa Nowak Elzbieta Marasek Agnieszka Kucharska Danuta 《Plant Cell, Tissue and Organ Culture》1999,59(2):95-102
An effective system for in vitro regeneration of adventitious shoots from callus for the transformation or mutation of gerbera was developed. Callus was produced
from petioles of the youngest 3–4 leaves detached from auxillary shoots produced in vitro. Induction medium, on which leaves were incubated over 3 or 6 days, contained 2.3 μM thidiazuron and 0.53 μM α-naphthaleneacetic
acid. Explants were than transferred to one of three regeneration media with lower levels of growth regulators. Regeneration
was quantified over four (4-weeks each) passages at the time of explant transfer to fresh medium. Direct shoot regeneration
occurred during the first 4 weeks, and after these shoots were discarded a semi-compact organogenic callus was produced. Effectiveness
of shoot regeneration depended on four criteria: the cultivar (three cultivars were tested), the sequence of passage on regeneration
medium, the growth regulators in regeneration medium and the duration of the induction period. Regeneration potential from
calli of all cultivars increased from the first to the fourth passage. Duration of the incubation period on induction medium
(3 or 6 days) influenced regeneration to varying degrees, depending on the cultivar used and the regeneration medium contents.
There were no differences between two of the regeneration media – B, containing 2.2 μM 6-benzyladenine and 0.3 μM indole-3-acetic
acid and C, containing 4.4 μM 6-benzyladenine, 4.6 μM zeatin and 0.6 μM indole-3-acetic acid. Cultivar Mariola was the most
productive and regenerated more than seven shoots per callus in the fourth passage. Regeneration on medium B was further evaluated
on four additional gerbera cultivars.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献