An effective method for axillary bud culture and RAPD analysis of cloned plants in tetraploid black locust

An efficient micropropagation technique by axillary bud multiplication was established for cloning tetraploid black locust tree (Robinia pseudoacacia L.). The result showed that the optimal medium for shoot multiplication and elongation was Murashige and Skoog (MS) medium supplemented with 0.5 mg/l 6-benzylaminopurine in combination with 0.5 mg/l kinetin and 0.1 mg/l 1-naphthaleneacetic acid. The best medium for rooting was half-strength MS medium with 0.25 mg/l indole-3-butyric acid. In the present report, we examined the genetic fidelity of the micropropagated plants by the randomly amplified polymorphic DNA (RAPD) method with 25 primers. The cloned plants of tetraploid black locust showed complete stability.Abbreviations BAP 6-Benzylaminopurine - GA₃ Gibberellic acid - IBA Indole-3-butyric acid - KIN Kinetin - MS Murashige and Skoog medium - NAA 1-Naphthaleneacetic acid - PCR Polymerase chain reaction - RAPD Randomly amplified polymorphic DNACommunicated by M. Beckert     

Micropropagation of Three Varieties of Caralluma adscendens via Nodal Explants

A procedure for in vitro propagation of pharmaceutically valuable varieties of Caralluma adscendens from nodal explant, is described. The highest shoot multiplication with 80% frequency was achieved within one month on Murashige and Skoog’s medium supplemented with 8.87 μM BA. Shoot multiplication occurred in subsequent subcultures in culture bottles on MS medium. Regenerated shoots were rooted on half strength MS medium supplemented with NAA (0.54 μM) in all the three varieties. The rooted plants were hardened for establishment in soil.     

Micropropagation of meadowfoam (Limnanthes spp.)

Summary A rapid micropropagation system was developed for meadowfoam (Limnanthes spp. Brown) using four genotypes of three species. Murashige and Skoog (MS) medium supplemented with N⁶ benzyladenine (BA) and indole-3-acetic acid (IAA) at 0, 0.1, 0.5, 1.0 and 2.0 mg/l was tested for multiplication, shoot elongation and rooting. Expiants were taken from pot-grown plants. The most useful level for shoot growth and multiplication of both floral induced and non-induced plants was 0.5 mg/l BA. IAA failed to affect shoot growth or multiplication. Expiants from non-induced plants multiplied at moderate to high rates on 0.5 mg/l BA, while those from induced plants multiplied slowly and tended to elongate and flower. Non-induced plants on 2 mg/l BA produced large numbers of tiny shoots; induced plants did not respond. Shoots of all genotypes rooted on MS medium without hormones and all plants grew normally after transplanting to soil. This system provides a new tool for the development of meadowfoam as a crop plant.Abbreviations (BA) N ⁶ -benzyladenine - (IAA) indole-3-acetic acid - (MS) Murashige and Skoog medium, 1962     

In vitro plant regeneration in the genus Cucumis

Plants were regenerated from cotyledonary and root explants of cucumber (Cucumis sativus L.) cultivars and breeding lines of diverse sex type, growth habit, and processing quality and from cotyledonary explants of muskmelon (C. melo L.). Somatic embryogenesis was induced on a medium consisting of Murashige and Skoog (MS) salts supplemented with 1.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), 1.0 mg/l α-naphthaleneacetic acid and 0.5 mg/l 6-benzylaminopurine. Embryos matured on the same medium without 2,4-D, and developed into normal plants on a hormone-free MS medium. Cucumber plants were also regenerated from cotyledonary protoplasts using a modified tomato protocol.     

In vitro propagation of shoot buds of Carica papaya L. (caricaceae) var. Honey Dew

Shoot buds from the saplings and the fruit bearing plants of Carica papaya L.. var. Honey Dew (papaya) initially treated with Gentamycin were cultured in modified MS media, each with a different hormonal combination, for the establishment of cultures and multiplication and rooting of plants. About 43% of explants from fruit bearing plants and 69% of those from saplings remained free of contamination and retained regeneration capacity when treated in 500 mg/l Gentamycin. For the establishment of the explants a medium containing 1 mg/l GA₃ and 2 mg/l kinetin was necessary. When established buds were transferred to medium containing 1 mg/l NAA and 3 mg/l kinetin, calli were initiated at cut ends of shoot buds; multiplication started on transfer to NAA (0.1 mg/l) and BAP (0.5 mg/l) medium. Cultures have been maintained for the last twenty months without any loss in multiplication rate. Rooting was induced in medium with reduced salt concentration containing 2 mg/l IBA. Shoot elongation was induced after prolonged culture in the same rooting medium.Abbreviations MS Murashige and Skoog, 1962 - SH Schenk and Hildebrandt, 1972 - GA₃ Gibberellic acid - Kn Kinetin - NAA Napthaleneacetic acid - BAP 6 -Benzylaminopurine - IBA Indole-3-butyric acid - IAA Indole-3-acetic acid     

Micropropagation of Zeyheria montana Mart. (Bignoniaceae), an endangered endemic medicinal species from the Brazilian cerrado biome

Zeyheria montana Mart. has become endangered, primarily because of deforestation of its habitat, its use as a medicinal plant extract, and the strong endemism of the species. In this study, an efficient protocol was established for the micropropagation and conservation of Z. montana germplasm using isolated mature zygotic embryos as explants. Embryos germinated in vitro 4 d after isolation and inoculation on modified Murashige and Skoog (MS) medium containing 2.0 mg/l gibberellic acid (GA₃). The addition of GA₃ also improved the germination index and accelerated the process of germination. Nodal segments from seedlings were placed on modified ¼-strength MS medium containing 0.1 mg/l 6-benzyladenine and 0.5 mg/l GA₃. Nodal segments produced 7.3 shoots per explant within 60 d. Following transfer of shoots to a medium containing 1.5 mg/l indole-3-butyric acid, roots formed. All plantlets obtained were successfully acclimatized under greenhouse conditions, and approximately 68.5 acclimatized plants could be obtained per seed each year. This protocol provides a method to preserve this rare and endangered medicinal plant.     

Micropropagation of Cephaelis ipecacuanha rich

Shoot cultures of ipecac, Cephaelis ipecacuanha Rich. were established by inoculating seedling nodal explants onto modified Murashige and Skoog's medium supplemented with 8 mg/l kinetin, 0.05 mg/l NAA and 200 mg/l adenine. Upto 12 new axillary shoots per explant were induced after 12 weeks incubation. Shoot cultures were also established by placing shoot tips on medium containing 0.1–0.25 mg/l NAA with 8 mg/l kinetin for 4 weeks and then to shoot multiplication medium for 8 weeks. The multiplication was maintained over several passages. Shoots were rooted using 2 mg/l IBA and normal plants were re-established.     

Micropropagation of Mandevilla moricandiana (A.DC.) Woodson

A protocol was developed for micropropagation of Mandevilla moricandiana (A.DC.) Woodson, a native plant from Brazil. Shoots, obtained from in vitro plantlets were used as source of nodal segments for shoot production from axillary buds. The nodal segments were grown on Murashige and Skoog medium supplemented with different concentrations of 6-benzyladenine and/or indole-3-acetic acid to induce axillary bud elongation. After a 2-mo culture period, the medium supplemented with 1.0 mg?L^?1 6-benzyladenine gave the largest number of nodal segments per explant. The nodal segments obtained from plants developed under these conditions were grown on medium supplemented with different concentrations indole-3-acetic acid, ??-naphthaleneacetic acid, and indole-3-butyric acid. The use of the medium supplemented with indole-3-acetic acid and indole-3-buryric induced shoot elongation and shoot development, formation of basal callus, and/or indirect organogenesis of roots. Following transfer of shoots to soil, the plants with only basal callus showed 10% survival and developed roots from callus, while in vitro-rooted plants had a maximum 40% survival rate ex vitro. Regardless of the auxin added to the rooting medium, the acclimatization period allowed the plants rooted in vitro to develop their shoots fully. The protocol developed here is suitable for the production of shoots and rooted plantlets of M. moricandiana.     

Micropropagation of Heracleum candicans wall: A rare medicinal herb

Summary A protocol was developed for micropropagation of Heracleum candicans Wall. by axillary shoot proliferation. Maximum shoot proliferation was obtained on Murashige and Skoog medium supplemented with 0.5 mg (2.2 μM) 6-benzyladenine per 1 and 0.1 mg (0.4 μM) 1-naphthaleneacetic acid per 1. Regenerated shoots were rooted on MS medium fortified with 1 mg (4.9 μM) indole-3-butyric acid per 1. Complete plants were transferred to soil and all of these plants were morphologically and cytologically identical to the mother plant.     

Micropropagation of Eucalyptus benthamii to form a clonal micro-garden

Eucalyptus benthamii is an important component of forestry plantations in cold regions, but it is difficult to obtain clonal plants of this species, especially by low rooting. In this study, we developed a method for cloning selected genotypes of E. benthamii using a micropropagation technique, enabling the formation of a clonal micro-garden. Nodal segments from sprouts of mini-stumps in the clonal mini-garden were used as explants. After in vitro establishment of the explants, we tested two selected clones (BP101 and BP118), three culture media (Wood Plant Medium (WPM), Correia and colleagues JADS medium, and Murashige and Skoog medium), and two plant growth regulators (6-benzylaminopurine (BAP) and ??-naphthaleneacetic acid (NAA)) for the multiplication of adventitious buds. Additionally, combinations of two other plant growth regulators (BAP and gibberellic acid (GA₃)) were tested for the elongation of shoots. The in vitro and ex vitro rooting of micro-plantlets prior to acclimatization were compared. The in vitro bud multiplication of E. benthamii depended on the clone, culture medium, and concentration of plant growth regulators. The best results were obtained with WPM supplemented with 0.5?mg?L^?1 BAP and 0.05?mg?L^?1 NAA. The elongation of shoots depended on the clone and plant growth regulator, and the best results were obtained with nutrient medium free of GA₃ and BAP. Histological analysis showed that both in vitro and ex vitro rooting were successful, resulting in normal development of adventitious roots showing a vascular connection with the vascular cambium. The new protocol is efficient for micro-plantlet production of E. benthamii and can be used for the formation of a clonal micro-garden for other Eucalyptus or tree species.     

Plant regeneration from leaf protoplasts of <Emphasis Type="Italic">Solanum virginianum</Emphasis> L. (<Emphasis Type="Italic">Solanaceae</Emphasis>)

Leaves of Solanum virginianum plants were used for protoplast isolation. To support cell wall formation and cell division, protoplasts were cultured in thin alginate layers floated in liquid medium. When protoplasts were plated at a density of 1.0 × 10⁶/ml in Kao and Michyaluk (KMp8) medium supplemented with 0.5 mg/l zeatin, 1.0 mg/l 2,4-dichlorophenoxyacetic acid, and 1.0 mg/l α-naphthaleneacetic acid, 42.3% of the dividing cells developed microcalli in 3–4 weeks. Shoot formation via organogenesis of protoplast-derived calli was achieved for 28% of calli transferred to solidified KMp8 medium supplemented with 2.0 g/l zeatin and 0.1 mg/l 3-indol acetic acid in about 2 weeks. Further shoot development was observed in Murashige and Skoog (MS) medium without growth regulators and roots were induced after transfer to MS medium containing 1.0 mg/l 3-indol butyric acid. Regenerated plants have normal morphology.     

Regeneration of Lycium barbarum L. plants from leaf tissue,callus culture and callus protoplasts

The possibility of plant regeneration from leaf tissue, callus and callus protoplasts of Lycium barbarum L. has been studied. Leaf segments were cultured on B5 medium (Gamborg et al. 1968) containing 1.5 mg/1 6-benzylaminopurine and 0.5 mg/1 -naphthaleneacetic acid. Regeneration of shoots was initiated after 30 days of cultivation. Callus was obtained from leaf and internode tissues on MS medium (Murashige and Skoog 1962) containing 0.4 mg/1 of 2,4dichlorophenoxyacetic acid. Subsequently, callus was successfully subcultured on the same medium with 1 mg/l of 2,4-dichlorophenoxyacetic acid and 0.2 mg/l -naphthaleneacetic acid. Organogenesis in callus culture was obtained in the course of 40 days after transferring to TM-4 (Shahin 1984). Protoplasts were isolated from callus tissue grown in vitro using an enzymatic method. Cell colonies, minicallus formation and organogenesis were obtained. Shoots were rooted on Murashige and Skoog medium containing 0..1 mg/l -naphthaleneacetic acid. Regenerated plants were transferred to soil and were grown to maturity. Regenerated plants carried normal morphological traits.Abbreviations BA 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid - NAA -naphthaleneacetic acid - Zea zeatin - GA₃ gibberellic acid - MS Murashige and Skoog medium - B5 Gamborg medium     

In vitro propagation of the Damask rose (Rosa damascena Mill.)

Roses are an important commercial crop available in a wide range of varieties in international markets. Due to its economic value, this study aimed to establish a new and reproducible protocol for the in vitro propagation of Rosa damascena Mill. We developed an efficient and cost-effective method for rapid and high-quality shoot multiplication and in vitro rooting of Damask rose using nodal explants. For each stage of the micropropagation procedure (i.e., explant establishment, shoot multiplication and growth, and rooting), different media and combinations of plant growth regulators were utilized. A new culture medium, termed A₁₉, resulted in significant improvements to shoot proliferation and root induction for this rose cultivar. For optimal explant establishment, shoot growth, and proliferation, a modified Murashige and Skoog medium with higher levels of nitrates, calcium, and iron plus supplementation with 4?mg/l 6-benzylaminopurine and 0.25?mg/l indole-3-acetic acid was utilized. To increase shoot length, 75?d after culture initiation (including two subcultures), shoots were transferred to the same medium additionally supplemented with 0.2?mg/l gibberellic acid. This resulted in vigorous shoot growth, with longer shoots and a greater number of shoots per explant. Shoots were then separated and transferred to various root induction medium for 30?d. The results clearly showed that a liquid ?A₁₉ medium-A (i.e., with half-strength macroelements) supplemented with 0.1?mg/l indole-3-butyric-acid was the most successful medium for in vitro rooting in this cultivar. Shoots were cultured in this medium for 7?d in the dark, before transfer to liquid ?A₁₉ medium-A without hormone supplementation under a 16-h photoperiod. This modified protocol resulted in significant improvement in shoot regeneration and proliferation and obtained stronger shoots over a period of about 20?wk.     

Micropropagation of lily (Lilium longiflorum) via in vitro stem node and pseudo-bulblet culture

A protocol for micropropagation of Lilium longiflorum using pseudo-bulblets from in vitro shoot-tip-derived stem nodes was developed. Shoot tips from stems of dormant bulbs were cultured on one-half Murashige and Skoog (MS) medium. Stems from plantlets derived from the shoot tips were cut into nodal segments, which were then cultured on one-half MS medium supplemented with 1 μm 6-benzyladenine (BA). Pseudo-bulblets formed on each node after 1 month. An average of 32 pseudo-bulblets were formed on all nodes of the plantlet. Pseudo-bulblets gave rise to multiple shoots when cultured on one-half MS medium supplemented with 2.3 μm BA. Shoots were rooted on one-half MS medium containing 1.1 μm α-naphthaleneacetic acid. A continuous system of propagation by multiplication of pseudo-bulblets with no dormancy period was developed. The 80 flowering plants produced from shoot tip culture were acclimatized in the greenhouse for 3 months and then grown in the experimental garden for 8 months. Received: 29 October 1997 / Revision received: 28 April 1998 / Accepted: 3 May 1998     

Somatic embryogenesis of Agave victoria-reginae Moore

Plant regeneration through direct somatic embryogenesis of leaf blade explants from in vitro propagated plants of Agave victoria-reginae Moore, is described. Somatic embryogenesis was evident in a 6-week period on agarsolidified MS medium supplemented with L2 vitamins and 2,4-dichlorophenoxyacetic acid (1,4 µM), and germination of somatic embryos was achieved after 8 weeks on half-strength MS medium and 4 weeks on half-strength SH medium, both lacking growth regulators. Hyperhydricity of somatic embryos and plantlets was reduced by the use of vented culture vessel lids during the last 4 weeks on SH medium. Shoot proliferation was obtained, and hyperhydricity was eliminated on a modified MS medium (with NH₄NO₃ reduced to 5 mN) supplemented with kinetin (4.6 µM) and 1-naphthaleneacetic acid (1.6 µM) and the use of vented culture vessel lids.Abbreviations 2,4-d 2,4-dichlorophenoxyacetic acid - NAA 1-naphthaleneacetic acid - MS Murashige and Skoog - LOG-1 MS modified medium by Castro-Concha et al. (1990) - L2 Phillips and Collins (1979) vitamins - SH Schenk and Hildebrandt     

In vitro propagation of herbaceous peony (paeonia lactiflora pall.) by a longitudinal shoot-split method

A procedure for the clonal propagation ofPaeonia lactiflora Pall. cvs. Takinoyosooi and Sarah Bernhardt through shoot tip culture is described. Half strength Murashige and Shoog (1962) medium supplemented with 0.5 mg/l 6-benzylaminopurine plus 1 mg/l gibberellic acid promoted formation and growth of axillary buds. Continuous shoot multiplication was achieved by vertically splitting the shoot axis and subsequent division of elongated axillary shoots every 36 days. High frequency (57–100%) of rooting was obtained on paper-bridge liquid medium supplemented with 1 mg/l indole-3-butyric acid. Half of the rooted plantlets were established on porous soil. Thus, 700 and 300 plants of cv. Takinoyosooi and Sarah Bernhardt could be theoretically obtained from a single bud in one year.Abbreviations BAP 6-benzylaminopurine - GA gibberellic acid - NAA a-naphthaleneacetic acid - IBA indole-3-butyric acid - MS Murashige and Skoog (1962) basal medium     

In vitro propagation of Homalomena aromatica Schott., an endangered aromatic medicinal herb of Northeast India

A successful report on the in vitro propagation of Homalomena aromatica via rhizome axillary bud multiplication is presented. Rhizome bud explants were cultured on Murashige and Skoog medium supplemented with various concentrations of cytokinins to induce multiple shoot formation for micropropagation. The highest number of shoots was achieved in MS medium supplemented with 2.0 mg?l^?1 6-benzylaminopurine. The regenerated shoots rooted most efficiently on half-strength MS medium supplemented with 0.5 mg?l^?1 α-naphthalene acetic acid. The regenerated plantlets showed no morphological differences from the parent plant. This protocol takes approximately 6 months to reach the acclimatization stage from the initiation stage and facilitates commercial and rapid propagation of H. aromatica.     

Plant regeneration from mesophyll protoplasts of Williams' Bon Chretien (syn. Bartlett) pear (Pyrus communis L.)

Leaf protoplasts of axenic shoot cultures of Pyrus communis L. cv. Williams' Bon Chretien (syn. Bartlett) underwent cell wall regeneration and division to give multicellular colonies in a modified Murashige and Skoog medium which lacked ammonium ions, but supplemented with 1-naphthaleneacetic acid (NAA), 4-indole-3yl-acetic acid, 6-benzylaminopurine (BAP) and casein hydrolysate. Protoplast-derived colonies gave callus on Murashige and Skoog salts medium with NAA and BAP and exhibited shoot regeneration on half-strength Murashige and Skoog medium supplemented with 0.2 mg 1^–1 4-indole-3yl-butyric acid, 2.0 mg 1^–1 BAP, 0.2 mg 1^–1 gibberellic acid, 50 mg 1^–1 casein hydrolysate and 10 mg 1^–1 Ca-pantothenate. Following rooting, protoplast-derived plants of pear were transferred to the glasshouse where they completed acclimatization.Abbreviations BAP 6-benzylaminopurine - FPE final plating efficiency - GA₃ gibberellic acid - IAA 4-indole-3yl-acetic acid - IBA 4-indole-3yl-but yric acid - IPE initial plating efficiency - NAA 1-naphthaleneacetic acid - f.wt. fresh weight - MES 2-N-morpholinoethane sulfonic acid - MS Murashige and Skoog (1962) - %PE % plating efficiency - PVP-10 polyvinylpyrrolidone (Av. MW 10,000) - FDA fluorescein diacetate     

Repetitive somatic embryogenesis from peanut cultures in liquid medium

Summary A regeneration system based on repetitive somatic embryogenesis was developed for peanut (Arachis hypogaea L.). Embryogenic suspension cultures were initiated using individual somatic embryos induced from immature cotyledons cultured on a modified Murashige and Skoog medium containing 40 mg/l 2,4-D for 30 days. After transfer to a modified MS liquid medium, the somatic embryos produced masses of secondary and tertiary embryos which continued to proliferate following manual separation and subculture of the embryogenic clumps. The cultures exhibited exponential growth, and have been maintained for over one year without apparent loss of embryogenic potential. Further embryo development, germination, and conversion were achieved by placing embryo clumps onto hormone-free, solid medium. The inclusion of a desiccation period during embryo development enhanced conversion four-fold. Plants have been established in soil and appear to be phenotypically normal.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - NAA 1-naphthaleneacetic acid - BA 6-benzylaminopurine - MSO Modified Murashige and Skoog basal medium - EM embryogenic masses     

Conservation ofHypericum foliosum aiton, an endemic azorean species, by micropropagation

Summary One of the first Azorean endemic vascular taxa chosen for the development ofin vitro multiplication techniques wasHypericum foliosum Aiton, due to its colonizing ability (Sj?gren, 1984), a loss of seed germination capacity after only 1 yr of storage (Maciel, 1994), and the populations' generally low number of individuals. The following culture media were tested usingHypericum foliosum's single node cuttings: Murashige and Skoog (1962), Roest and Bockelmman (1973), Lloyd and McCown (1980), C?rte and Mendon?a (1985), and Cellárová et al. (1992). Further experiments were performed on CM medium supplemented with four different growth regulators: α-naphthaleneacetic acid (NAA), N⁶-benzyladenine (BA), γ, γ-(dimethylallyl) aminopurine (2iP), and kinetin (KIN). The acclimatization stage was carried out in Jiffy 7? pots and in a 2∶1 or 1∶1 peat/perlite mixture. We found that micropropagation ofHypericum foliosum is possible on CM medium and that the best results with growth regulators were achieved with the following supplements: 0.1 mg/l (0.4 μM) BA and 0.5 mg/l (2.6 μM) NAA+1.0 mg/l (4.4 μM) BA (in the initiation stage), and 0.1 mg/l (0.4 μM) BA (in the elongation stage). As for culture multiplication, 0.1 mg/l (0.4 μM) BA (in the initiation stage) and 0.5 mg/l (2.6 μM) NAA+1.0 mg/l (4.4 μM) BA (both in the initiation and elongation stages), proved to be the most efficient concentrations. The acclimatization stage was successfully performed in Jiffy 7? pellets.