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1.
Multiple shoots were induced on stem segments of an 8-y-old plant of Metrosideros excelsa Sol ex Gaertn. “Parnel”. Axillary shoots produced on uncontaminated explants were excised, segmented, and recultured in the same medium to increase the stock of shoot cultures. The Murashige and Skoog (MS) medium, augmented with different concentrations of 2- isopenthenyladenine (2iP) and indole-3-acetic acid (IAA), either singly or in combinations, as potential medium for shoot multiplication by nodal segments was tested. In the following experiment, equal molar concentrations of four cytokinins [2iP, kinetin, zeatin, and N 6-benzyladenine (BA)] in combination with equal molar concentrations of three auxins [IAA, α-naphthaleneacetic acid (NAA), and indole-3-butyric acid (IBA)] were tested for ability to induce axillary shoot development from single-node stem segments. The highest rate of axillary shoot proliferation was induced on MS agar medium supplemented with 1.96μM 2iP and 1.14μM IAA after 6 wk in culture. Different auxins (IAA, IBA, and NAA) were tested to determine the optimum conditions for in vitro rooting of microshoots. The best results were accomplished with IAA at 5.71μM (89% rooting) and with IBA at 2.85 or 5.71μM (86% and 86% rooting, respectively). Seventy and 90 percent of the microshoots were rooted ex vitro in bottom-heated bench (22 ± 2°C) after 2 and 4 wk, respectively. In vitro and ex vitro rooted plantlets were successfully established in soil.  相似文献   

2.
Summary Side shoots excised from underground dormant buds ofCynara scolymus L. were used as primary explants to establishin vitro cultures. A 3×3 factorial experiment with all possible combinations of three concentrations (0.5, 1.0, 2.0 mg/liter or 2.22, 4.44, 8.88 μM) ofN 6-benzyladenine (BA) and three concentrations (0, 0.1, 0.2 mg/liter or 0, 0.54, 1.07 μM) of 1-naphthaleneacetic acid (NAA) was used to determine the optimum growth regulator combination for shoot multiplication. The highest rate of axillary shoots was induced on Murashige and Skoog agar medium supplemented with 0 mg NAA/liter and 1.0 mg BA/liter (4.44 μM). Other cytokinins tested (kinetin, zeatin, and 2-isopentenyl-adenine were less effective than BA in inducing axillary shoot growth. Up to 60% of elongated microshoots rooted after 5 weeks on 1/2 MS agar medium supplemented with 2 mg/liter (11.42 μM) indole-3-acetic acid (IAA). Seventy percent of rooted plantlets were transferred successfully into soil. Plants are under evaluation for their genetic uniformity and clonal fidelity.  相似文献   

3.
Summary Shoot tips and leaves excised from in vitro shoot cultures of Salvia nemorosa were evaluated for their organogenic capacity under in vitro conditions. The best shoot proliferation from shoot tips was obtained on Murashige and Skoog (MS) medium supplemented with 8.9 μM 6-benzylaminopurine (BA) and 2.9 μM indole-3-acetic acid (IAA). Leaf lamina and petiole explants formed shoots through organogenesis via callus stage and/or directly from explant tissue. The highest values for shoot regeneration were obtained with 0.9 μM BA and 2.9 μM IAA for lamina explants. No shoot organogenesis was obtained on leaf explants cultured on MS medium supplemented with α-naphthaleneacetic acid (NAA). The regenerated shoots rooted the best on MS medium containing 0.6 μM IAA or 0.5 μM NAA. In vitro-propagated plants were transferred to soil with a survival rate of 85% after 3 mo.  相似文献   

4.
Summary A protocol was developed for rapid clonal propagation of the important medicinal climber, Tinospora cordifolia, through in vitro culture of mature nodal explants. Shoots were initiated on both Murashige and Skoog (MS) medium and woody plant medium (WPM) supplemented with 2.32 μM kinetin (KIN). Of the two basal media tested, WPM was found to be superior to MS medium for the induction of multiple shoots. Among the cytokinins tested, N6-benzyladenine (BA) was more effective than KIN for axillary shoot proliferation. KIN was superior to BA in terms of shoot elongation. An average multiplication rate of 6.3 shoots per explant was obtained with WPM supplemented with 8.87 μM BA. Shoot clumps harvested from this medium were transferred to WPM supplemented with 2.22 μM BA and 4.65 μM KIN for shoot elongation. Elongated shoots were rooted in half-strength MS medium supplemented with 2.85 μM indole-3-acetic acid (IAA). Rooted plantlets were successfully transferred to sand and established with 80% survival.  相似文献   

5.
Summary Protocols for both axillary bud proliferation and shoot organogenesis of Euphorbia pulchurrima Winter RoseTM were developed using terminal buds and leaf tissues. Greenhouse-grown terminal buds were placed on Murashige-Skoog (MS) basal medium supplemented with various concentrations of either benzlyaminopurine (BA) or thidiazuron (TDZ). Explants produced the greatest number of axillary buds on media containing between 2.2 and 8.8 μM BA. The number of explants that produced axillary buds increased with increasing BA concentration. TDZ at concentrations between 2.3 and 23.0 μM caused hyperhydricity of shoots and were not effective in promoting shoot proliferation. The most calluses and shoots were produced from leaf midvein sections from in vitro grown plants placed on the medium containing 8.8–13.3 μM BA and 17.1 μM indole-3-acetic acid (IAA) for 1 mo. before transferring to the medium containing only BA. Adventitious buds were produced only from red-pigmented callus, and explants that produced callus continued to produce adventitious shoots in the presence of IAA. Five-mo.-old shoots derived from shoot culture or organogenesis rooted readily in artificial soil with or without treatment with indolebutyric acid, and were acclimatized in the greenhouse.  相似文献   

6.
Summary Two independent experiments were performed to establish micropropagation of Cleome spinosa from stem segments. In the first experiment, direct shoot organogenesis on hypocotyl explants from 2-mo.-old nursery-grown seedlings was obtained on Murashige and Skoog medium with different combinations of benzyladenine (BA) and 6-furfurylaminopurine, added either individually or in combination. Best proliferation rates occurred in the presence of 2.2 and 4.4 μM BA and the highest mean number of shoots was produced in response to 4.4 μM BA. In the second experiment, regeneration via direct organogenesis was also obtained from nodal and internodal segments of axenic plants cultured in the presence of BA (4.4 and 8.8 μM) in association with indole-3-acetic acid (IAA) (0.57 and 1.14 μM). Internodal explants were the most responsive on all media tested. The best mean number of shoots per explant was achieved on medium with 4.4 μM BA in association with 0.57 μM IAA. Histological studies of the globular structures formed at the apical portion of the explants revealed direct shoot regeneration and adventitious shoot differentiation from meristematic centers around the vascular bundles of the primary regenerants. All shoots elongated and rooted on MS0 medium. The acclimatization rates ranged between 70 and 84%. Plants reached to maturity and flowered 4 mo. after transfer to ex vitro conditions.  相似文献   

7.
Summary A protocol for in vitro shoot regeneration from cotyledon explants of Citrullus lanatus (Thunb.) Matsum. & Nakai cv. Sugar Baby is described. The cotyledons excised from 7-d-old aseptic seedlings showed the highest percentage of shoots on Murashige and Skoog (MS) + N6-benzyladenine (BA; 3.0 μM) + N6-[2-isopentenyl] adenine (2iP; 3.0 μM) and MS + BA (3.0 μM) + indole-3-acetic acid (IAA; 3.0 μM). Whereas the latter medium induced shoot regeneration after the callusing of the explant, the former stimulated direct shoot formation. The regenerated shoots were rooted and the resulting plants were established in earthen pots with 55% success.  相似文献   

8.
Summary An efficient, rapid and large-scale propagation of the woody, aromatic and medicinal shrub, Holarrhena antidysenterica, through in vitro culture of nodal segments with axillary buds, is described. N6-benzyladenine used at 15 μM was the most effective in inducing bud break and growth, and also in initiating multiple shoot proliferation at the rate of 43 microshoots per nodal explant with axillary buds, after 30 d of eulture. By repeated subculturing of nodal explants with axillary buds, a high-frequency multiplication rate was established. Efficient rooting was achieved with 35 μM indole-3-butyric acid which was the most effective in inducing roots, as 80% of the microshoots produced roots. Plantlets went through a bardening phase in a controlled plant growth chamber, prior to ex vitro transfer Micropropagated plants established in garden soil were uniform and identical to donor plants with respect to growth characteristics and vegetative morphology.  相似文献   

9.
Summary Currently,Cereus peruvianus plants can be rapidly clonedin vitro via adventitious organogenesis using callus cultures; however, somaclonal variation is a problem. A method is described herein using lateral bud explants to produce multiple shoots for clonal propagation. Apical and lateral explants were cultured on MS (Murashige and Skoog, 1962) media with factorial combinations of the auxins indole-3-acetic acid (IAA), 1-naphthaleneacetic acid (NAA), and cytokinins 6-ben-zyladenine (BA) and N-(2-furanyl-methyl)-1-purine-6 amine (kinetin) at the concentrations 0.0, 0.01, 0.1, 1.0 mg“l−1. Positive results were obtained from the lateral explants in all conditions tested, but apical explants did not respond toin vitro multiplication ofC. peruvianus cactus at all growth regulator combinations tested. Formation of axillary shoots inC. peruvianus seems most frequent in medium containing BA at 1.0 mg·l−1 (4.44 μM) and IAA or NAA at 1.0 mg·l−1 (5.71 μM or 5.37 μM respectively), but the frequency of shoot formation in the BA or kinetin and NAA or IAA combinations indicated that any of the combinations tested can be used for multiplication ofC. peruvianus plants regenerated from callus tissue culture. Root formation occurred in all (100%) of the cactus shoots after 9 wk in the same culture medium. All the cacti that developed at the different auxin and cytokin combinations continued growth after transfer to a potting mix of red earth (Paleudult) and ground river sand (1∶1).  相似文献   

10.
Summary Micropropagation of the anti-cancer plant Camptotheca acuminata Decaisne from axillary buds and seed embryos was investigated. Axillary buds from greenhouse seedlings required a period of culture in media free of N6-benzyladenine (BA) before multiple shoot induction began. Direct induction of multiple shoots on BA-containing medium resulted in high mortality of the axillary buds. Multiple shoot induction from the greenhouse axillary buds was best achieved on B5 with 4.4 μM BA+0.5μM α-naphthaleneacetic acid, forming an average of three 2-mm tall shoots per bud in 8 wk. Elongation of these multiple shoots was successful at a lower BA level (0.22 μM) on B5 medium. Both in vitro and ex vitro rooting of the microcuttings was feasible with indole-3-butyric acid in the culture media, but ex vitro rooting led to high plantlet survival. Seed embryos were not ideal explants for multiple shoot induction. Shoot tips and axillary buds of in vitro-germinated seedlings showed an optimal multiple shoot formation on B5 with 8.9 μM BA, double the optimal BA level for greenhouse axillary buds. Using axillary buds to propagate C. acuminata plants in vitro is feasible for mass propagation of desired clonal lines high in camptothecin concentrations.  相似文献   

11.
Summary Adventitious shoot regeneration was achieved from almond leaves, cv. Boa Casta, excised fromin vitro cultures of juvenile and adult material. Murashige and Skoog (1962) medium (MS) was found to be more efficient for adventitious shoot induction than a modified medium of Quoirin et al. (1977) when using identical growth regulator supplements. Thidiazuron (TDZ) at 4.54, 5.90, 6.81, and 9.08 μM was used in all induction media, together with indole-3-butyric acid (IBA), indole-3-acetic acid (IAA), or a combination of IAA and 2,4-dichlorophenoxyacetic acid (2,4-D). When N6-benzyladenine (BA) was used instead of TDZ, no adventitious shoots were induced. Leaf explants of juvenile origin yielded the highest regeneration rates (40.0 and 38.2%) and required higher concentrations of TDZ for shoot induction than leaves of adult origin. An increase from 15.0 to 35.3% in the regeneration ability of adult leaf explants, tested on one of the induction media, modified medium of Quoirin et al. (1977) supplemented with 5.90 μM TDZ and 2.85 μM IAA], was achieved when donor shoots were subcultured twice on a medium with a low BA concentration of 1.33 μM.  相似文献   

12.
Summary A protocol for micropropagation of plants via axillary bud proliferation from nodal explants of Terminalia bellirica Roxb. seedlings has been established. Explants were cultured on Murashige and Skoog medium with different concentrations of 6-benzyladenine (BA; 4.4, 8.9, 13.3, 17.8, or 22.2 μM) or kinetin (Kn; 4.6, 9.3. 14.0, 18.6, or 23.2 μM). Within the range evaluated, the medium containing 13.3 μM BA showed the highest shoot length (1.9=0.2 cm) in the primary culture. When separated and transferred to fresh subculture medium with lower levels of BA (2.2. 4.4, 6.6, or 8.9 μM) or Kn (2.3, 4.6, 6.9, or 9.3 μM), the nodal segments from individual regenerants (obtained initially from seedling nodes) showed efficient shoot induction at 4.4 μM BA. Rooting of the shoots was achieved under in vitro conditions on two media tested, i.e., modified Gamborg's (B5) medium or Woody Plant Medium, both supplemented with 4.9 μM indole-3-butyric acid. Regenerated plants were established in the greenhouse.  相似文献   

13.
Summary An efficient protocol for in vitro propagation of the valuable medicinal plant, Wasabia japonica (Miq.) Matsumura is described through shoot tip proliferation and direct regeneration. Multiple shoots were induced from shoort tips cultured on Murashige and Skoog (MS) semi-solid medium containing various concentrations (0.5–50 μM) of N6-benzyladenine (BA), thidiazuron, kinetin, and zeatin. A comparison was made on shoot multiplication between semi-solid and liquid culture media. Well-developed shoots were obtained using full-strength MS semi-solid medium containing 5.0 μM BA. However, the greatest shoot proliferation was achieved on either full- or half-strength MS liquid media supplemented with 5.0 μM BA for 4 wk (15.3±0.9 and 15.0±0.7 shoots per explant, respectively), and on half-strength MS liquid medium for 6 wk (25.8±1.3 shoots per explant) in culture. In contrast, the maximum number of shoots per explant on full-strength MS semi-solid medium was achieved with either 5.0 μM BA (10.4±0.6 shoots per explant) or 10.0 μM kinetin (10.9±0.8 shoots per explant). Fresh weight of explants and length of shoots derived from full-strength MS liquid medium (1055±77 mg and 34.2±1.0 mm, respectively) were significantly higher than those derived from full-strength MS semisolid medium (437.6±17.3 mg and 15.4±0.7 mm, respectively). Quarter-strength MS liquid medium had no significant difference in shoot proliferation when compared to quarter-strength MS semi-solid medium. Elongated shoots were separated and rooted on half-strength MS semi-solid media fortified with 1-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA), or indole-3-acetic acid (IAA) ranging from 0.1 to 10.0 μM. Root formation was greatest with IBA when compared with IAA and NAA. One hundred percent of shoots were rooted on half-strength MS medium with 5.0 μM IBA, while vigorous roots were obtained with 10.0 μM IBA. Micropropagated plantlets were successfully established in soil with 95% survival rate after heardening.  相似文献   

14.
Summary Embryonal explants from water chestnut (Trapa japonica Flerov) seeds germinated with high efficiency following a 40-d cold treatment at 5°C on half-strength MS (Murashige and Skoog) medium supplemented with 2.7 μM N6-benzyladenine (BA), 0.5 μM 1-naphthaleneacetic acid (NAA) and 0.5 μM gibberellic acid (GA3). Control and chill-treated (different durations) embryonal explants were cultured onto media which contained half-strength MS medium supplemented with different concentrations and combinations of cytokinins [BA, thidiazuron (TDZ), kinetin, zeatin], auxin (NAA) and GA3. A liquid half-strength MS medium with 1.1 μM BA and 0.5 μM NAA resulted in the best shoot proliferation of control or chill-treated explants, and the addition of 0.5 μM GA3 stimulated axillary shoot elongation. Germination and shoot proliferation were always greater for chill-treated explants compared with control explants under the same culture conditions. Shoots produced in vitro rooted 100% of the time in a liquid half-strength MS medium with 1.1 μM BA, 0.5 μM NAA and 1.1 μM indole-3-butyric acid, and the regenerated plantlets were established successfully in a water chestnut paddy field.  相似文献   

15.
Internode explants collected from in vitro grown shoots of two clones of Fagus sylvatica L. (European beech) and five clones of F. orientalis Lipski (Oriental beech) were used to evaluate their bud regeneration capacity. Adventitious shoot-buds formed on callus, which developed from internode segments cultured in a Woody Plant Medium supplemented with different concentrations of either thidiazuron (TDZ) or benzyladenine (BA). After 4 weeks of culture on induction media, the explants were transferred to a proliferation medium supplemented with 2.2 μM BA, 9.1 μM zeatin and 2.9 μM indole-3-acetic acid (IAA) for another 8 weeks. Medium containing TDZ was much more efficient than medium containing BA in inducing adventitious buds, the optimal TDZ concentration being 4.5 μM and the optimal BA concentration 17.8 μM. Genotypic variation in shoot regeneration capacity was observed among the two Fagus species and between clones within each species, with a significant interaction between TDZ concentration and genotype regarding mean bud number. Thidiazuron induction medium supplemented with a range of individual auxins was investigated, and it was found that IAA or indole-3-butyric acid at 2.9 μM enhanced the bud forming capacity of explants. Morphogenic response varied significantly with the position of the internode along the stem. The highest regeneration potential was obtained from apical internodes, while those distal to the apex were the least productive. Elongated shoots of adventitious origin can be readily proliferated by axillary branching. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

16.
Summary A method for adventitious shoot induction from petiole explants of Heracleum candicans is reported. Shoot buds were induced on Murashige and Skoog (MS) medium with 4.4μM 6-benzylaminopurine (BA) and 1.1 μM 2,4-dichlorophen-oxyacetic acid (2,4-D). A wound response in the presence of BA and 2,4-D at the time of culture was necessary for inducing shoot buds. The shoot bud regeneration was significantly influenced by size, type and orientation of explants on the culture medium. These shoot buds developed into 4–5 cm shoots upon transfer to a medium containing 1.1μM BA and 0.5 μM α-naphthaleneacetic acid (NAA). The regenerated shoots formed rooted plantlets on MS medium supplemented with 4.9 μM indole-3-butyric acid (IBA). About 15 plants were established in the field for further evaluation.  相似文献   

17.
Summary Micropropagation is a technique to ensure a constant and uniform source of medicinal plants. In this report, we describe the micropropagation of Lepidium virginicum L. (Brassicaceae), a wild plant used as an antiamoebic in traditional Mexican medicine. In vitro-germinated seeds were cultured in Murashige and Skoog (MS) medium to obtain pathogen-free cotyledons, hypocotyls, and apical bud (AB) explants. For induction of morphogenesis, the effect of cytokinins, benzyladenine (BA) and kinetin (KN), combined with auxin, indole-3-acetic acid (IAA) was evaluated. The best rate of shoot proliferation was induced 15 d after culture on MS mineral medium supplemented with IAA∶KN (0.57∶13.94 μM) from AB explants. Maximum shoot elongation was achieved without plant growth regulators. The effect of indole-3-butyric acid (IBA) (14.76 μM) was evaluated for in vitro root induction; 60 d after culture all the shoots had developed roots. All rooted plants were successfully transferred to pots and 100% acclimatized in ex vitro conditions. The methanol extracts from the micropropagated active explants of L. virginicum showed and IC50 antiprotozoal value between 141.90 and 268.53 μg ml−1.  相似文献   

18.
Summary We have developed a highly efficient two-stage protocol for induction of multiple shoots from single node in vitro shoot tip explants of Decalepis hamiltonii. It was found that phenylacetic acid (PAA) had a synergistic effect on shoot multiplication when treated with N6-benzyladenine (BA). This protocol used PAA for both multiple shoot induction from nodal explants, elongation of primary shoots, and initiation of adventitious shoot formation from primary shoots. Murashige and Skoog medium containing BA (2.22–31.08 μM) and α-naphthaleneacetic acid (0.27–10.74 μM) or PAA (7.34–36.71 μM) was used to initiate shoot formation from nodal explants. The maximum number of shoots per culture was produced on a medium containing 31.08 μM BA and 14.68 μM PAA, while the longest shoot length and nodes were obtained on medium containing 22.2 μM BA and 14.68 μM PAA. Shoots subcultured on MS medium containing 22.2 μM BA and 14.68 μM PAA elongated along with secondary shoot formation. The shoots were rooted on medium containing 9.7 μM indole-3-butyric acid. The plantlets were acclimatized in soil with an 80–90% survival rate under field conditions.  相似文献   

19.
Summary A viable protocol has been developed for direct and indirect shoot regeneration of Vernonia cinerea. To establish a stable and high-frequency plant regeneration system, leaf and stem explants were tested with different combinations of α-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), and benzylaminopurine (BA). Lateral buds on nodal explants grew into shoots within 2 wk of culture in Murashige and Skoog (MS) basal medium supplemented with 20.9 μM BA. Excision and culture of nodal segments from in vitro-raised shoots on fresh medium with the same concentration of BA facilitated development of more than 15 shoots per node. Similarly leaf, nodal, and internodal explants were cultured on MS basal medium supplemented with different concentrations of BA, NAA, and IAA either alone or in combinations for callus induction and organogenesis. Shoot buds and/or roots were regenerated on callus. Shoot buds formed multiple shoots within 4 wk after incubation in induction medium. Adventitious buds and shoots proliferated when callus was cut into pieces and subcultured on MS basal medium containing 20.9 μM BA and 5.3 μM NAA. This combination proved to be the best medium for enhanced adventitious shoot bud multiplication, generating a maximum of 50 shoots in 4 wk. This medium was also used successfully for shoot proliferation in liquid medium. Root formation was observed from callus induced in medium containing 8.05–13.4 μM NAA. Regenerated shoots exhibited flowering and root formation in MS basal medium without any growth regulators. Plantlets established in the field showed 85% survival and exhibited identical morphological characteristics as the donor plant.  相似文献   

20.
Summary The in vitro plant regeneration potential of vegetatively propagated geraniums (Pelargonium x hortorum) has been investigated. Using various combinations of growth regulators and a choice of different explants, a regeneration protocol has been developed to raise in vitro plantlets from young petiole and leaf explants from three different cultivars of geraniums. In all three cultivars, very young petiole explants exhibited a higher regeneration potential as compared with leaf explants. Regeneration efficiencies were found to be highly dependent on the cultivar, with cv. Samba showing the highest regeneration potential, followed by cvs. Yours Truly and then Sincerity. Samba also showed the highest number of shoots from both the petiole [57 shoot buds per petiole explant in the presence of 3 μM zeatin and 1 μM indole-3-acetic acid (IAA) and leaf explants (43 shoots per leaf explant with 10 μM zeatin and 2 μM IAA). Shoot buds transferred to Murashige and Skoog (MS) medium supplemented with 0.44 μM N6-benzyladenine and 0.11 μM IAA grew vigorously and attained 1–2 cm in length in 3–4 wk. These shoots rooted with 100% efficiency on MS basal medium, and plants developed that showed normal growth and flowering under greenhouse conditions.  相似文献   

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