In vitro clonal multiplication of mature trees of Dalbergia sissoo Roxb.

Multiple shoots were obtained from nodal explants of 30-year-old trees of Dalbergia sissoo Roxb. on a defined medium, MS (Murashige & Skoog medium) supplemented with auxin-cytokinin combinations. IAA (Indole accetic acid) alone promoted 15% rooted shoot buds. A combination of IAA+Kn (Kinetin) gave 100% rooted shoot buds. A combination of NAA (napthaleneacetic acid) + Kn and NAA+BAP (6-benzylaminopurine) also gave high percentages of rooted shoot buds. Ascorbic acid in the medium prevented the death of callus and plantlets, which followed darkening of the medium.     

Rapid in vitro multiplication of jujube through mature stem explants

Stem explants obtained from a mature tree of Ziziphus mauritiana Lamk were grown on modified Murashige and Skoog medium containing 3800 mg l^-1 potassium nitrate, 2475 mg l^-1 ammonium nitrate, 11 M benzyladenine and 0.5 M indole-3-acetic acid. During successive subcultures 15–20 shoots per inoculum were produced. Rooting was induced by pretreatment with 50 M indolebutyric acid or 1-naphthaleneacetic acid for 24 h followed by transfer to auxin-free White's medium. Plantlets grew well in a soil and vermiculite mixture.Abbreviations IAA Indole-3-acetic acid - NAA 1-naphthaleneacetic acid - BA benzyladenine - MS Murashige and Skoog     

Simplified clonal multiplication of mulberry using liquid shake culture

Organogenesis was induced in callus derived from mature zygotic embryos of six families of loblolly pine (Pinus taeda L.) within 24 weeks of culture. Elongation of adventitious buds was achieved on TE medium supplemented with 0.5 mg l⁻¹ indole-3-butyric acid (IBA) and 2 mg l⁻¹ 6-benzyladenine (BA). The most suitable medium for root formation proved to be TE medium supplemented with 0.1 mg l⁻¹ IBA, 1 mg l⁻¹ BA, and 0.5 mg l⁻¹ gibberellic acid (GA₃). One hundred and sixty-nine regenerated plantlets were transferred to a perlite:peatmoss:vermiculite (1:1:1) soil mixture, and 98 plantlets survived in the field. This revised version was published online in June 2006 with corrections to the Cover Date.     

Vegetative multiplication of sugarbeet through in vitro culture of inflorescence pieces

In vitro vegetative multiplication of sugarbeet was obtained by culturing of inflorescence explants. Subapical segments or 5-mm-long tips from nine varieties developed axillary shoots (up to 50 per tip) on a medium containing indolebutyric acid (IBA) and benzylaminopurine (BAP). Zeatin was ineffective as cytokinin. Gibberellic acid (GA₃) enhanced the process. Such vegetative shoots were subsequently isolated and were each allowed to develop up to 20 supplementary axillary shoots on a multiplication medium containing IBA, BAP, and naphthaleneacetic acid (NAA). Rooting of shoots was obtained in the absence of growth regulators and plants were established.     

Establishment and multiplication of colchi-autotetraploids of Rauvolfia serpentina L. Benth. ex Kurz. through tissue culture

A tissue culture procedure was developed for the establishment and propagation of a colchi-autotetraploid of Rauvolfia serpentina for possible commercial exploitation. Multiplication of autotetraploid shoots was obtained either through axillary bud elongation on Murashige and Skoog [1] medium (MS) containing 2.65 M (0.5 mgl^–1) -naphthaleneacetic acid and 0.33 M (0.05 mgl^–1) kinetin, or via multiple shoot formation on MS medium supplemented with 4.44 M (1.0 mgl^–1) 6-benzylaminopurine and 0.53 M (0.1 mgl^–1) -naphthaleneacetic acid. Rooting could be induced by transferring the shoots to MS medium containing 7.95 M (1.5 mgl^–1) -naphthaleneacetic acid alone. The plantlets, thus formed, were tetraploid in nature by cytological observations of the root tips. They exhibited 80–90% success in establishment under glass house and field conditions.     

Propagation of Asparagus racemosus through tissue culture

Murashige and Skoog's medium with 2, 4-D and kinetin induced callus in the shoot segments of Asparagus racemosus. Regeneration of shoot buds and clonal multiplication of excised shoots through proliferation of nodal buds could be achieved by the use of IAA and BAP in the medium. Rooting was achieved with half strength MS basal medium plus IBA. Complete plants with cladode, crown and root systems were developed in hormone free medium. The plants were successfully transferred to soil.     

Rapid clonal multiplication of Digitalis lanata in tissue culture

Shoot cultures of Digitalis lanata have been established by inoculating the shoot tip of seedlings germinated in aseptic culture, or of field-grown plants, onto Linsmaier and Skoog's RM medium supplemented with 1 mg 6-benzylaminopurine and 0.1 mg indolacetic acid 1^–1. On this medium formation of up to 30 new axillary shoots could be induced. Shoots could be grown into functional plants after root induction on a medium containing reduced amounts (one-fifth of normal) of nitrogen and indolebutyric acid (0.5 mg 1^–1).     

In vitro multiplication and microrhizome induction in Curcuma aromatica Salisb.

Shoot multiplication and plant regeneration was achieved from freshly sprouted shoots of Curcuma aromatica on Murashige and Skoog's medium supplemented with BA alone (1–7 mgL^–1) or a combination of BA(1–5 mgL^–1) and Kn (0.5–1 mgL^–1). A concentration of 5 mgL^–1 BA was optimum for shoot multiplication and rooting of shoots. The regenerated plants grew profusely on transfer to liquid medium.In vitro raised plants were successfully established in the field. Microrhizomes were induced at the base of the in vitro derived shoots upon transfer to medium containingvarious combinations and concentrations of sucrose and BA and grown under varying photoperiods. MS basal medium with 5 mgL^–1 BA, 60 gL^–1 sucrose and an8 h photoperiod was optimum for induction ofmicrorhizomes within 30 days of culture. Harvestedmicrorhizomes stored in moist sand in poly-bagssprouted after 2 months of storage at roomtemperature. For in vitro storage, microrhizomeswere grown in medium containing 0.1 mgL^–1 BA.Microrhizome formation was found to be controlled bythe concentrations of BA and sucrose as well asphotoperiod during culture.     

Clonal propagation of Cinnamomum zeylanicum Breyn. by tissue culture

Multiple shoot formation was induced directly from seeds of Cinnamomum zeylanicum Breyn. and also from seedling explants on Murashige and Skoog's medium containing different concentrations and combinations of auxins and cytokinins. Individual shoots were excised and induced to root on White's liquid medium. These plantlets were then transferred to pots in the green house and were eventually grown successfully under field conditions. Explants from the nodal region of these in vitro rooted plants were also subcultured to fresh medium. They produced a new crop of multiple shoots which could again be rooted by the same procedure.Abbreviations BAP 6-Benzylamino purine - 2,4-D 2,4-Dichlorophenoxy acetic acid - IAA Indole-3-acetic acid - IBA Indole-3-butyric acid - IPA Indole-3-propionic acid - KN Kinetin - NAA -Naphthalene acetic acid     

Rapid clonal propagation of Vitex trifolia

This report describes in vitro shoot induction and plant regeneration from mature nodal explants of Vitex trifolia L. on Murashige and Skoog (MS) medium fortified with benzylaminopurine (BAP), kinetin (KN), thidiazuron (TDZ), adenine (ADE), and 2-isopentenyladenine (2-iP) (0.25 – 10.0 μM). Multiple shoots differentiated directly without callus mediation within 3 weeks when explants were cultured on medium supplemented with cytokinins. The maximum number of shoots (9 shoots per explant) was developed on a medium supplemented with 5.0 μM BAP. Shoot cultures was established repeatedly subculturing the original nodal explant on the same medium. Rooting of shoots was achieved on half strength MS medium supplemented with 0.5 μM naphthaleneacetic acid (NAA). Rooted plantlets transferred to pots containing autoclaved soil and vermiculite mixture (1:1) showed 90 % survival when transferred to outdoor.     

In vitro clonal multiplication of 4-year-old plants of the bamboo,Dendrocalamus longispathus kurz

Summary A complete protocol for micropropagation of 4-yr-old plants of the bambooDendrocalamus longispathus is described. Culture initiation was strongly influenced by the nature of the explant and the season. In vitro multiplication was achieved through forced axillary branching. Single node segments from the young lateral branches produced multiple shoots on agar-solidified Murashige and Skoog (MS) medium supplemented with 12µM benzylaminopurine (BAP) and 3µM kinetin. The shoots have been multiplied for 15 passages in liquid and thereafter for over 5 passages on semisolid MS+15µM BAP+1µM indolebutyric acid (IBA)+10% coconut water at a rate of 3.2- and 2.8-fold, every 4 wk, respectively. The nature of the propagule was a critical factor for shoot multiplication and rooting. Seventy-three percent of the shoots rooted on a modified MS medium (major salts reduced to half strength) containing 1µM indoleacetic acid, 1µM IBA, and 68µM coumarin. Through a simple in vitro hardening step, more than 85% of the tissue culture-raised plants were successfully transferred to soil.     

Lateral bud culture of papaya (Carica papaya L.) for clonal propagation

Lateral buds may be preferred to shoot tips for in vitro propagation of papaya because of its unbranched nature. Proliferating shoot cultures from lateral buds appeared extremely compact with shortened internodes and leaf lamina of the cytokinin level (BAP 2 M) reported for multiple shoot production from shoot tips. ZEA (4 M) and 2iP (8 M) although reduced the proliferation rate, resulted in better growth of the shoot from lateral bud. Rooting was observed with IBA 20 M but plantlets so produced remained stunted.     

A contaminant,Erwinia carotovora,affecting commercial plant tissue cultures

Summary Commercial plant tissue cultures of several ornamental plants exhibiting reduced vigor and chlorosis in stage II were found to contain bacterial contaminants. In most cases, visible evidence of the contaminants in the tissue-culture medium was not easily discernible. Physiological and pathological tests employing pure cultures proved 5 of the 10 isolates obtained to beErwinia carotovora, an important pathogen of many horticultural plants. The tissue cultures from whichE. carotovora was isolated were of plant types nonsusceptible under normal commercial production methods. These results indicate nonhost plants may serve as carriers ofE. carotovora during tissue-culture propagation and also possibly under normal methods of commercial production. Florida Agricultural Experiment Stations Journal Series No. 883. This investigation was supported in part by The Fred C. Gloeckner Foundation.     

Clonal propagation ofBougainvillea glabra ‘Magnifica’ through shoot apex culture

Shoot apices ofBougainvillea glabra ‘Magnifica’ were induced to regenerate an average of ten shoots from their bases in response to BAP (0.5 mg/l) plus IAA (1.5 mg/l). All the isolated shoots from such cultures were rooted in a medium containing 0.1 mg/l each of IBA and 2,4,5-T and lacking BAP. Plantlets were then successfully grown in potted soil where they flowered normally. NBRI, research publication no. 32/80.     

降水对鄂尔多斯高原克隆植物分布的影响

鄂尔多斯高原地处半干旱区到干旱区的过渡带。通过沿鄂尔多斯高原从东到西的天然降水梯度的样带调查,分析了克隆植物的分布特征与降水的关系。结果表明:克隆植物的物种数量、占物种总数的比例和重要值以及根状茎型克隆植物的物种数量均与降水量呈显著正相关。5种优势植物克氏针茅、本氏针茅、黑沙蒿、赖草和短花针茅均为克隆植物,它们的分布也受降水影响。克氏针茅的密度、本氏针茅的盖度和密度、黑沙蒿的高度、盖度和密度以及赖草的高度均与降水量呈显著正相关。然而,赖草的盖度以及短花针茅的高度、盖度和密度均与降水量成负相关。因此,克隆植物在鄂尔多斯高原植被中具有重要作用,而且其作用随着降水量的增加而加强。     

Tissue culture of Hypericum brasiliense Choisy: Shoot multiplication and callus induction

Hypericum brasiliense, a non-domesticated plant has been shown to have useful medicinal properties. This plant has not been cultivated so a protocol for mass propagation based on selection of superior clones was developed and a protocol established for the culture of callus cells that could be used for in vitro metabolite production. A micropropagation method based on amplification of nodal buds was developed, by selection, from ten seedling clones that were examined for growth rate, multiplication rate and rooting. The effect of various basal media, growth regulator types and concentrations were examined for optimal callus induction. Optimal callus induction occured on either Murashige and Skoog's or Gamborg's media supplemented with 1 to 2 mg l^–1 of 2,4-dichlorophenoxyacetic acid.Abbreviations B5 Gamborg's medium - 2,4-Dscd 2,4-dichlorophenoxyacetic acid - IAA indolacetic acid - MS Murashige & Skoog's medium - NAA naphtaleneacetic acid     

Effects of tissue culture conditions during embryoid multiplication on the incidence of ``mantled' flowering in clonally propagated oil palm

New and established embryoid lines of oil palm (Elaeis guineensis Jacq.) clones, classified with regard to the expected risk of mantled flowering, were included in experiments to determine to what extent culture conditions during 48 weeks of embryoid multiplication could influence the incidence and severity of mantled flowering. Variables tested included clone risk status, duration of transfer interval, and plant growth regulator composition of the culture medium. Clones classified as high risk at the outset gave a significantly higher incidence of mantled flowering in the field than clones classified as low/medium risk, confirming that data on terminal inflorescences produced in vitro allows effective screening of material with regard to the risk of mantled flowering. The incidence of mantled flowering ranged from 0 to 100% depending on risk status of the clones, and the treatments applied. In general, a relatively long transfer interval (8 weeks) and a high auxin/cytokinin ratio resulted in the lowest incidence of mantled flowering with all types of material. Reducing the transfer interval down to 2 or 4 weeks, and/or using media with relatively high concentrations of kinetin (0.25 mg l^–1), and low concentrations of naphthalene acetic acid (0 or 0.1 mg l^–1), resulted in a high incidence of mantled flowering (above 30%), even with low/medium risk clones. Exclusion of plant growth regulators from the embryoid multiplication medium did not prevent some mantled flowering (12%) of new embryoid lines of low/medium risk clones following embryoid multiplication on a 4 week transfer interval, and a much higher incidence of mantling (above 90%) of lines from high risk clones.     

Advances in mulberry tissue culture

The mulberry (Morus spp.) is an important tree in the sericultural industry because its leaves constitute the sole source of food for the Mori silkworm (Bombyx mori). Qualitative and quantitative improvements in mulberry varieties play a vital role in industrial advances. However, the perennial nature of the plants, coupled with the species prolonged juvenile period, slows this process. Plant tissue-culture techniques have been used extensively for stock improvement During the last thirty years, several researchers have reported success in plant regeneration from different expiants types. This review describes the major findings in mulberry tissue-culture research.     

马可波罗百合的组织培养和离体快繁

以马可波罗百合的鳞片、茎段和茎尖为外植体 ,成功建立了快速无性繁殖系。诱导鳞片产生丛芽的最佳培养基为 :MS +0 .3～ 0 .8mg/LBA +0 .0 5mg/LNAA ;茎尖的最佳诱导培养基为 :MS +2mg/LBA +0 .0 5mg/LNAA ;茎段的最佳诱导培养基为 :MS +0 .8mg/LBA +0 .1mg/LNAA。丛芽增殖培养基 :MS +0 .2mg/LBA +0 .1mg/LNAA和MS +0 .2mg/LBA +0 .1mg/LIAA。生根诱导最佳培养基为 1 /2MS +0 .2mg/LKT +0 .0 5～ 0 .5mg/LNAA。     

Toward the production of artemisinin through tissue culture: Determining nutrient-hormone combinations suitable for cell suspension cultures

Summary Artemisia annua L. is the source of a potent antimalarial, artemisinin. As part of a program to produce artemisinin through tissue culture, a series of 14 multifactorial experiments were conducted to determine suitable conditions for initiating and maintaining friable callus fromA. annua. In the first six experiments, three different nutrient formulations [Gamborg B5 (B5), Murashige and Skoog (MS), and Whetmore and Rier (WR)], each with 32 combinations of auxins and cytokinins [2,4-dichlorophenoxyacetic acid (2,4-D) with benzyladenine (BA), or 1-naphthaleneacetic acid (NAA) with 6-furfurylaminopurine (kinetin)], were tested. Both B5 and WR nutrients supported friable callus formation from leaf explants with some combinations of auxin and cytokinin. Inasmuch as friable callus seemed to be produced over a wider range of auxin and cytokinin concentrations in combination with B5, the remaining experiments were conducted solely with this nutrient formulation. In the remaining eight experiments, it was determined that friable callus formed when combinations of NAA with kinetin or 2,4-D and BA were used with B5 medium. Lighter colored, more friable callus formed in response to 2,4-D and BA than with NAA and kinetin. No single combination of concentrations of auxin and cytokinin seemed to be “ideal” for producing friable callus. Ranges of 2,4-D from 0.5 to 2.0 with BA between 0.025 and 0.1, or NAA between 0.5 and 2.0 with kinetin between 0.5 and 1.0 mg/liter, produced acceptable results.