Tissue,cell culture and micropropagation of Mandevilla velutina,a natural source of a bradykinin antagonist

Leaf, stem and root explants of Mandevilla velutina were cultured in vitro and produced vigorous callus in LS basal medium containing one auxin (2,4-D or NAA) plus BAP. Calli can be subcultured indefinitely with vigorous growth. Subculture of calli to NAA (1.0 mg/l) plus BAP (5.0 mg/l) caused profuse regeneration of shoots. Isolated shoots were rooted in basal medium plus NAA (5.0 mg/l) or IBA (8.0 mg/l). Rapidly growing cell suspensions can be easily obtained from friable callus cultured in liquid medium.Abbreviations LS Linsmaier & Skoog - 2,4-D 2,4 dichlorophenoxi-acetic acid - NAA -naphthalene-acetic acid - GA₃ gibberellic acid - IAA indole-3-acetic acid - BAP 6-benzylaminopurine - IBA indole-3-butyric acid     

Mass propagation of <Emphasis Type="Italic">Plectranthus bourneae</Emphasis> Gamble through indirect organogenesis from leaf and internode explants

The present study describes the plant propagation via indirect organogenesis from in vitro derived leaf and internode explants of Plectranthus bourneae, an endemic plant to south India. Leaf and internodal explants successfully callused on Murashige and Skoog medium (MS) supplemented with different concentrations of auxins [2,4-D (2,4-dichlorophenoxyacetic acid), NAA (α-naphthalene acetic acid), IAA (indole-3 acetic acid), IBA (indole-3-butyric acid) and PIC (Picloram); 0.1–2.0 mg/l] in combination with BA (6-benzyladenine) (0.5 mg/l). Maximum callus induction (98 %) was achieved from leaf explant followed by internodal explant (89 %) at 1.0 mg/l NAA, 0.5 mg/l BA. Leaf derived callus showed better shoot regeneration (29.71 shoots) on MS medium containing 1.0 mg/l KN (kinetin), 0.7 mg/l NAA, and 50 mg/l CH (casein hydrolysate) followed by internodal callus (19.71). A maximum of 19.14 roots/shoot was observed at 1.0 mg/l IBA. The rooted plantlets were successfully hardened and transferred to greenhouse condition with 80 % survival. This system could be utilized for large-scale multiplication of P. bourneae by tissue culture.     

Liquid culture for efficient micropropagation of Wasabia Japonica (MIQ.) matsumura

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.     

Micropropagation of Madhuca longifolia (Koenig) MacBride var. latifolia Roxb.

Bud break and multiple shoots were induced in apical and axillary meristems derived from 10-d old seedlings of Madhuca longifolia var. latifolia on Murashige and Skoog (MS) medium supplemented with 1.0 mg/l N⁶-benzyladenine (BA) singly or in combinatiobn with 1-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA). Excised shoots were rooted on half-strength MS with IBA (1.0 mg/l) after 18d of culture. Regenerated plantlets were acclimatized and successfully transferred to soil.Abbreviations BA N⁶ benzyladenine - KN kinetin - ADS adenine sulphate - IBA indole-3-butyric acid - IAA indole3-acetic acid - NAA 1-naphthaleneacetic acid - MS Murashige and Skoog (1962) medium     

Plant regeneration from callus cultures of Valeriana wallichii DC.

Petiole expiants of Valeriana wallichii. DC., a threatened medicinal plant, were used for inducing callus. Optimum callus formation was observed on Murashige and Skoogs' (1962) medium supplemented with 3.0 mg/l NAA and 0.25 mg/l Kn. Shoot regeneration was achieved upon transferring the callus to medium containing 1.0 mg/l Kn and 0.25 mg/l NAA. Complete plantlets were obtained on the same medium or upon transfer of the regenerated shoot buds to medium containing 5.0 mg/l Kn and 1.0 mg/l IAA. Nearly a thousand callus regenerated plants were successfully transferred to the field following previously standardized hardening procedures.Abbreviations BAP 6-Benzylaminopurine - 2,4-D 2,4-dichloro phenoxyaceticacid - 2iP 2-isopentenyladenine - IAA indole-3-acetic acid - IBA indole-3-butyric acid - Kn Kinetin - MS Murashige and Skoog's medium (1962) - NAA -napthalene aceticacid - Z Zeatin     

Direct shoot regeneration from leaf explants of <Emphasis Type="Italic">Spilanthes acmella</Emphasis>

Multiple shoots of Spilanthes acmella Murr. were induced from nodal buds of in vivo and in vitro seedlings on Murashige and Skoog (MS) medium containing 1.0 mg dm⁻³ 6-benzyladenine (BA) and 0.1 mg dm⁻³ α-naphthalene-acetic acid (NAA). Adventitious shoots were successfully regenerated from the leaf explants derived from the above mentioned multiple shoots. The efficiency of shoot regeneration was tested in the MS medium containing BA, kinetin, or 2-isopentenyl adenine in combination with NAA, indole-3-acetic acid (IAA), or indole-3-butyric acid (IBA) and gibberellic acid. Maximum number of shoots per explant (20 ± 0.47) was recorded with 3.0 mg dm⁻³ BA and 1.0 mg dm⁻³ IAA. An anatomical study confirmed shoot regeneration via direct organogenesis. About 95 % of the in vitro shoots developed roots after transfer to half strength MS medium containing 1.0 mg dm⁻³ IBA. 95 % of the plantlets were successfully acclimatized and established in soil. The transplanted plantlets showed normal flowering without any morphological variation.     

In vitro morphogenesis of organogenic nodules derived from <Emphasis Type="Italic">Sclerocarya birrea</Emphasis> subsp. <Emphasis Type="Italic">caffra</Emphasis> leaf explants

Sclerocarya birrea (marula) is an indigenous South African tree with highly valued medicinal and nutritional properties. Induction of nodular meristemoids from leaf explants was achieved on Murashige and Skoog (MS) and woody plant medium (WPM) supplemented with 6-benzyladenine (BA) in combination with naphthalene acetic acid (NAA), indole-3-butryric acid (IBA) and indole-3-acetic acid (IAA). Induction of nodular meristemoids from 86% of the leaf cultures was achieved on MS medium with 4.0 μM BA and 1.0 μM NAA. High levels (78–100%) of induction were also achieved on WPM with different concentrations of BA (1.0–4.0 μM) and IBA (1.0–4.0 μM). The highest conversion of meristemoids into shoots was only 22% for 4.0 μM BA and 1.0 μM NAA on MS initiation medium. This was improved to 62% when nodular clusters were cultured in a MS liquid medium. Histological studies revealed the globular stage of the nodular meristemoids. This protocol has potential for application in mass micropropagation and plant breeding of S. birrea.     

Chitosan and silver nanoparticles are attractive auxin carriers: A comparative study on the adventitious rooting of microcuttings in apple rootstocks

Nanocarriers for encapsulation and sustained release of agrochemicals such as auxins have emerged as an attractive strategy to provide enhanced bioavailability and efficacy for improved crop yields and nutrition quality. Here, a comparative study was conducted on the effectiveness of chitosan-as a biopolymeric nanocarrier- and silver-as a metallic nanocarrier- on in vitro adventitious rooting potential of microcuttings in apple rootstocks, for the first time. Auxins indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) loaded silver (nAg) or chitosan nanoparticles (nChi) were synthesized. Scanning electron microscopy and transmission electron microscopy studies showed the spherical shape of the nanoparticles. The average particle size of IAA-nChi was 167.5 ± 0.1 nm while that of IBA-nChi was 123.2 ± 2.6 nm. The hydrodynamic diameter of the nAg-IAA and nAg-IBA particles were measured as 93.66 ± 5 nm and 71.41 ± 3 nm, respectively. Fourier transform infrared spectroscopy analyses confirmed the encapsulation of IAA or IBA in the chitosan nanoparticles. Meanwhile, the characteristic peaks of IAA or IBA were detected on silver nanoparticles. In-vitro adventitious rooting of microcuttings of Malling Merton 106 (MM 106) was significantly higher both in chitosan and silver nanoparticles loaded with IAA or IBA (91.7%–62.5%) compared to free IAA or IBA applications (50.0%–33.3%), except for 2.0 mg L^–1 IBA (66.7%). However, the application of 2 mg L^–1 IBA and IBA-nChi at all concentrations caused an undesirable large callus development.     

An efficient micropropagation system for Tylophora indica: an endangered, medicinally important plant

An efficient protocol is described for the rapid in vitro multiplication of an endangered medicinal plant, Tylophora indica (Burm. f.) Merrill, via enhanced axillary bud proliferation from nodal explants collected from young shoots of a two-year-old plant. The physiological effects of growth regulators [6-benzyladenine (BA), kinetin (Kin) thidiazuron (TDZ), indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) or α-naphthalene acetic acid (NAA)], ascorbic acid (AA), different strengths of Murashige and Skoog (MS) medium and various pH levels on in vitro morphogenesis were investigated. The highest number (8.6 ± 0.71) of shoots and the maximum average shoot length (5.2 ± 0.31 cm) were recorded on MS medium supplemented with 2.5 μM BA, 0.5 μM NAA and 100 mg/l AA at pH 5.8. Rooting was best achieved on half-strength MS medium augmented with 0.5 μM IBA. The plantlets regenerated in vitro with well-developed shoot and roots were successfully established in pots containing garden soil and grown in a greenhouse with a 90% survival rate. The regenerated plants did not show any immediate detectable phenotypic variation. The described method can be successfully employed for large-scale multiplication and long-term in vitro conservation of T. indica.     

Effects of ascorbic acid on axillary shoot induction in Tylophora indica (Burm. f.) Merrill.

A procedure for rapid in vitro multiplication of Tylophora indica (Burm. f.) Merrill., an important indigenous medicinal plant, has been developed. Addition of ascorbic acid was essential to induce sprouting of axillary buds. Optimum multiplication was observed on MS medium containing 6-benzylamino purine (5.0 mg l^–1), -naphathalene-acetic acid (0.5 mg l^–1) and ascorbic acid (100 mg l^–1). Rooting of in vitro produced shoots was readily achieved with indole-3-acetic acid alone (1.0 mg l^–1) in MS. The plantlets thus obtained were successfully transferred to pots in large numbers which grew normally.Abbreviations BAP 6-benzylamino purine - 2,4-D 2,4-dichlorophenoxyacetic acid - GA₃ gibberellic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid - 2ip 2-isopentenyladenine - Kn kinetin - MS Murashige & Skoog media - NAA -naphthalene acetic acid     

Micropropagation of <Emphasis Type="Italic">Metrosideros excelsa</Emphasis>

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.     

Clonal propagation of Picrorhiza kurroa royle ex benth. by shoot tip culture

A procedure has been developed for the clonal propagation of Picrorhiza kurroa Royle ex Benth. through shoot tip culture. Murashige and Skoog's medium (1962) supplemented with kinetin (3.0 to 5.0 mg/l) supported rapid proliferation of multiple shoots from the explants. Addition of indole-3-acetic acid (1.0 mg/l) to the kinetin containing medium showed marked improvement in the growth of regenerated shoots. However, presence of IAA in the medium did not alter the frequency of shoot multiplication. Rooting was readily achieved upon transferring shoots onto MS medium containing -naphthaleneacetic acid (1.0 mg/l). Plantlets were successfully transferred to soil.Abbreviations BAP 6-benzylaminopurine - IAA indole-3-acetic acid - IBA indole-3-butyric acid - Kn Kinetin - MS Murashige and Skoog's (1962) medium - NAA -naphthaleneacetic acid     

Plant regeneration from protoplasts of immature Vigna sinensis cotyledons via somatic embryogenesis

Summary Protoplasts were isolated from immature cotyledons of Vigna sinensis and cultured in a modified MS Liquid medium containing 0. 2 mg/l 2, 4-dichlorophenoxyacetic acid (2, 4-D), 1 mg/l naphthaleneacetic acid (NAA) and 0. 5 mg/l 6-benzylaminopurine (BAP) in the dark at a density of 1 × 10⁵/ml. The protoplasts began to divide in 3–5 days. Sustained cell division resulted in formation of cell clusters and small calli, with the cell division frequency and plating efficiency of cell colonies reaching 27. 7% and 1. 7% respectively. When calli of 2 mm in size were transferred onto MSB medium (MS salts and B5 vitamins) containing 500mg/l NaCl, 500 mg/ 1 casein hydrolysate (CH), 2 mg/l 2,4-D and 0. 5 mg/l BAP for further growth, approximately 5% of the calli developed embryogenically. The embryogenic calli were selected and subcultured on the same composition of MSB medium and were able to maintain somatic embryogenesis capacity in subculture for a long time. When the calli were moved to MSB medium with 0. 1 mg/l indole-3-acetic acid (IAA), 0. 5mg/l kinetin(KT), 3–5% mannitol and 2% sucrose in the light, many somatic embryos formed from the calli. Only part of the embryoids developed further to the cotyledonary stage, and the others died at the globular, heart-shaped or torpedo stages. Finally, some cotyledonary embryoids germinated and developed into plants or shoots. The shoots were readily rooted on 1/2 strength MS medium with 0. 1–0.3 mg/l indole-3-butyric acid (IBA). The plants grew well in soil and were fertile.Abbreviations 2, 4-D dichlorophenoxyacetic acid - NAA naphthaleneacetic acid - BAP 6-benzylaminopurine - IAA indole-3-acetic acid - KT kinetin - IBA indole-3-butyric acid - CH casein hydrolysate - CM coconut milk - ZT zeatin     

In vitro propagation of Coleus forskohlii Briq., a threatened medicinal plant

In vitro clonai multip1ication of Coleus forskahlii Briq a threatened plant, has been achieved on MS medium supplemented with Kn (2.0 mg/l) and IAA (1.0 mg/l) using nodal segments as explants, Shoots multiplied at a rate of 12 — fold every six weeks. Rooting was achieved upon transfer of shoots onto MS medium containing IAA (1.0 mg/l). The micropropagated plants were successfully established under field conditions. Forskolin content in tubers of plants obtained by micropropagation was found to be 0.1%, the same as that found in wild plants. This micropropagation procedure should be useful for conservation as well as production of this important plantAbbreviations BAP 6-benzylaminopurine - IAA indole-3-acetic acid - IBA indole-3-butyric acid - Kn Kinetin - MS Murashige and Skoog (1962) basal medium - NAA -naphthalene acetic acid     

Direct somatic embryogenesis and plantlet regeneration from seedling leaves of winged bean,Psophocarpus tetragonolobus (L.) DC

Excised seedling leaf segments of winged bean [Psophocarpus tetragonolobus (L.) DC.] underwent direct somatic embryogenesis under appropriate incubation conditions. Initiation and development of the somatic embryos occurred using a two-step culture method. The culture procedure involved incubation for 28 days on MS basal medium supplemented with 0.1–0.5 mg/l NAA and 1.0–2.0 mg/l BA (induction medium) before transfer to MS medium supplemented with 0.1 mg/l IAA and 2.0 mg/l BA (embryo development medium). The initial exposure to low levels of NAA coincident with high levels of BA in the induction medium was essential for embryogenic induction. Maximum embryogenesis (43.3%) was obtained with 0.2 mg/l NAA and 2.0 mg/l BA, and at least 14 days on induction medium were required prior to transfer to the embryo development medium. The conversion frequency of cotyledonary embryos was 53.3% upon culture on MS medium containing 0.1 mg/l ABA for 7 days followed by transfer to MS medium supplemented with 0.1 mg/l IBA and 0.2 mg/l BA. Following conversion, the regenerated plantlets were transferred to soil and showed normal morphological characteristics.Abbreviations MS Murashige and Skoog (1962) medium - 2,4-D 2,4-dichlorophenoxyacetic acid - NAA 1-naphthaleneacetic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid - BA 6-benzylaminopurine - ABA abscisic acid     

In vitro plant regeneration from cotyledon and hypocotyl segments in two bell pepper cultivars

In vitro plant regeneration has been obtained from Capsicum annuum cvs. Pico and Piquillo. Shootbuds were induced from hypocotyl and cotyledon segments after 15–20 days of culture on MS basal medium supplemented with IAA and BAP or Zeatin. Shoot-buds grew into rosettes that rooted in MS plus NAA (0.1 mg/l) and IBA (0.05 mg/l) after 15 days. The small plantlets were successfully transferred to pots with a mixture of peat and perlite and maintained under greenhouse conditions. Elongation took place when the plantlets were growing in the greenhouse.Abbreviations BAP 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid - Kn Kinetin - MS Murashige and Skoog (1962) - NAA alpha-naphthalenacetic acid - Z Zeatin     

Annatto pigment production in root cultures of Achiote (<Emphasis Type="Italic">Bixa orellana</Emphasis> L.)

Bixa orellana L. is a tree native to South America known for its reddish orange pigment ‘annatto’ produced only on the aril portion of its seeds. It is the most preferred natural food colorant next to saffron, having wide applications in the dairy industry and also as a cosmeceutical. Normal root cultures of B. orellana were established under in vitro conditions on Murashige and Skoog (MS) medium containing α-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA) at 0.05–0.2 mg l⁻¹. The annatto pigment from in vitro-raised normal roots was extracted with chloroform, and later the ethanol-dissolved extract was analyzed both qualitatively by thin-layer chromatography (TLC) and spectrophotometrically quantified followed by High Performance Liquid Chromatography (HPLC) confirmation. The maximum amount of annatto pigment (346 ± 3.8 mg/100 g dry wt.) and maximum root biomass (152 ± 2.5 mg dry wt.) were recorded after 45 and 60 days of growth, respectively, on MS medium containing 0.1 mg l⁻¹ indole-3-butyric acid (IBA). Producing annatto pigment from normal root cultures under in vitro conditions is a novel approach when compared to the natural annatto pigment that is produced only on the aril portion of seeds. This allows the production of fresh pigment throughout the year.     

Expression of a KDEL-tagged dengue virus protein in cell suspension cultures of <Emphasis Type="Italic">Nicotiana tabacum</Emphasis> and <Emphasis Type="Italic">Morinda citrifolia</Emphasis>

Hypericum perforatum L. (St. John’s wort) produces a number of phytochemicals having medicinal, anti-microbial, anti-viral and anti-oxidative properties. Plant extracts are generally used for treatment of mild to medium cases of depression. Plant regeneration can be achieved in this species by in vitro culture of a variety of explants. However, there are no reports of regeneration from petal explants. In this report plant regeneration from petal explants of St. John’s wort was evaluated. Petals of various ages were cultured on agarized Murashige and Skoog 1962 (MS) medium supplemented with auxin and cytokinin (kinetin), maintained in the dark and callus and shoot regeneration determined after 28 days. At an auxin to cytokinin ratio of 10:1, callus and shoot formation were induced by all levels of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA), while 2,4-dichlorophenoxyacetic acid (2,4-D) induced only callus formation. The optimum level of auxin for shoot regeneration was 1.0 and 0.1 mg/l kinetin, where the regeneration frequency was 100 percent for all three auxins. The highest number of shoots per explant (57.4 and 53.4) was obtained with IAA and IBA, respectively. In the absence of auxin, kinetin levels of 0.1 and 0.25 mg/l induce callus and shoot formation at low frequency but not at lower levels. Callus and shoot formation did not occur in the absence of growth regulators. Petal-derived shoots were successfully rooted on half-strength MS medium without a requirement for exogenous auxin and flowering plants were established under greenhouse conditions. From these results it can be concluded that auxin type is a critical factor for plant regeneration from petal explants of Hypericum perforatum and there is no absolute requirement for high levels of cytokinin.     

Plant regeneration through direct shoot formation from leaf cultures and from protocorm-like bodies derived from callus of <Emphasis Type="Italic">Encyclia mariae</Emphasis> (Orchidaceae), a threatened Mexican orchid

Two procedures for the in vitro propagation of Encyclia mariae, a threatened Mexican orchid, were developed. In the first procedure, leaves from in vitro germinated seedlings were cultured on Murashige and Skoog medium (MS) supplemented with the range of 2.21–4.4 μM 6-benzylaminopurine (BA) in combination with 2.69–10.74 μM naphthalene acetic (NAA), 2.07–8.29 μM indole-3-butyric (IBA), or 2.85–11.42 μM indole-3-acetic acid (IAA) to determine the best medium for the induction of shooting. Maximum direct shoot formation from leaves was observed on MS containing 22.21 μM BA and 10.74 μM NAA (25 shoots/explant). The second procedure began with the culture of protocorms on media containing NAA, IBA, or IAA, which induced callus formation with high regenerative potential in the form of protocorm-like-bodies (PLBs) that eventually differentiated into shoots. The optimal response was attained when these structures were cultured on medium with 4.14 μM IBA (30 shoots/PLB). To promote the elongation of shoots derived from PLBs, the material was subcultured onto MS medium containing 22.21 μM BA and 5.37 μM NAA. Through the exploration of the effects of auxins and matrix on the rooting of shoots, it was determined that the optimal rooting occurred on media supplemented either with 5.71 μM IAA or 4.14 μM IBA either on agar-gelled medium or in liquid media with coir as the matrix. Rooting was found to be 20% higher in liquid media than in agar-gelled medium.     

Shoot organogenesis and plant regeneration in <Emphasis Type="Italic">Metabriggsia ovalifolia</Emphasis>

An efficient propagation and regeneration system via direct shoot organogenesis for an endangered species, Metabriggsia ovalifolia, was established. High activity cytokinins [6-benzyladeneine (BA) and thidiazuron (TDZ)] and low activity auxins [α-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA)] could directly induce adventitious shoots from leaf or petiole explants within 5 weeks. Cytokinins (TDZ or BA) combined with auxin (NAA) in the induction media induced more adventitious shoots than when auxins or cytokinins were used alone. Adventitious shoots could be induced and also mass-propagated on media containing 2.5–5.0 μM TDZ (or BA) and 0.25–0.5 μM NAA. Adventitious roots differentiated at the proximal end of shoots on rooting media containing half-strength MS salts and 0.5 μM IBA, 0.5 μM NAA, 0.1% activated charcoal or no plant growth regulators. Over 90% of plantlets survived following acclimatization and transfer to a potting mixture (1:1, sand:vermiculite) in basins.