In vitro Clonal Propagation and Organogenesis in Spilanthes acmella (L) Murray: A Herbal Pesticidal Plant of North-East India

Multiple shoots were regenerated in MS medium using different concentrations of BAP and Kn and different combinations of BAP with IAA, NAA and IBA. Highest multiplication of shoots was obtained with BAP (0.75 mg l^?1) with 28.4 shoots per explant after 60 days of culture. Shoots rooted best on IBA (0.5 mg l^?1), numbering 48.8 per explant. Organogenesis was maximum in callus cultured on MS medium supplemented with BAP (2.0 mg l^?1) and IAA (1.0 mg l^?1).     

Glycerol stimulation of chlorophyll synthesis,embryogenesis, and carboxylation and sucrose metabolism enzymes in nucellar callus of ‘Hamlin’ sweet orange

Anthers of niger (Guizotia abyssinica. Cass) were inoculated onto five different media differing mainly in their inorganic and organic constituents and plant growth regulators to study their influence on callus induction (embryogenic/non-embryogenic) and plant regeneration. LS medium supplemented with 2 mg 1^-1 2,4-d, and 0.3 mg 1^-1 KN favoured the production of EC, whereas 2 mg 1^-1 BAP and 0.5 mg 1^-1 KN promoted the NEC from anthers. Different types of embryos were initiated upon transfer of EC to Chaleff's R-2 medium containing 2 mg 1^-1 NAA and 0.3 mg 1^-1 KN and/or 5 mg 1^-1 ABA. NEC when transferred onto the medium supplemented with 1 mg 1^-1 BAP and 0.1 mg 1^-1 NAA produced on an average 8–12 shoots/callus mass. Embryoids developed from the EC and shoots differentiated from NEC when cultured onto the Chaleff's R-2 and MS media respectively lacking growth regulators, they transformed into whole plantlets. The plantlets thus obtained were successfully hardened and grown to maturity for analysis of various plant characters.Abbreviations EC embryogenic callus - NEC non-embryogenic callus - 2,4-d 2,4-dichlorophenoxyacetic acid - NAA -naphthaleneacetic acid - ABA abscisic acid - BAP 6-benzylaminopurine - KN kinetin - MS Murashige and Skoog's medium - LS Linsmaier and Skoog's medium     

Regeneration of plants from callus cultures of Origanum vulgare L.

Investigations were undertaken to achieve rapid multiplication and improvement of Origanum vulgare (a herbaceous, ornamental plant well known for its aromatic and medicinal value) through plant regeneration from callus. The explants (cotyledons, hypocotyl and root segments) excised from 15 d old aseptic seedlings were cultured on Gamborg's B₅ medium supplemented with 2,4-D, NAA and BAP individually and in various combinations (at concentrations of 0,10^–7,10^–6 and 10^–5 M). Best callus induction was noted on medium with 10^–7 M 2,4-D alone. The cotyledonary expiants proved to be the best source for compact and nodulated callus. The subcultured cotyledonary calli showed shoot induction when transferred onto media supplemented with BAP alone orin combination with 10^–7M or 10^–6MNAA. However, 10^–5M NAA completely suppressed the shoot inducing ability of BAP. In general, NAA promoted root induction from all explants used including cotyledonary callus. Best shoot induction was obtained on medium supplemented with 10^–6M BAP+10^–6MNAA. Both IBA and NAA at 10^–6 M proved to be equally effective in induction of roots from the cut ends of 15–20 mm long shoots (excised from callus) in half-strength B₅ liquid medium. Rooted shoots were successfully re-established in soil under controlled conditions.Abbreviations 2,4-D 2,4 dichlorophenoxyacetic acid - IBA indole-3-butyric acid - NAA -naphthaleneacetic acid - BAP 6-benzylaminopurine     

Somatic embryogenesis and plant regeneration in centipedegrass (Eremochloa ophiuroides [Munro] Hack.)

Centipedegrass (Eremochloa ophiuroides [Munro] Hack.) is an important warm-season turfgrass and pasture grass. To explore the potential use of biotechnical tools in breeding of centipedegrass, we established an efficient plant regeneration system for this species. Four basal media and 24 combinations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BAP) were examined for their effects on callus induction from mature seed explants. Twenty combinations of naphthaleneacetic acid (NAA) and BAP were tested for their effect on plant regeneration. Results indicated that Murashige and Skoog basal medium supplemented with 4.5 mg l⁻¹ 2,4-D and 1 mg l⁻¹ BAP was the best medium for callus induction, while the combination of 2 mg l⁻¹ BAP and 1 mg l⁻¹ NAA induced the highest rate of regeneration and development of shoots and roots. This work provides a basis for the breeding of centipedegrass through somaclonal variation and genetic transformation.     

A rapid and efficient method for regeneration of plantlets from embryo explants of cumin (Cuminum cyminum)

A new, simple and efficient method was developed for multiple shoot regeneration of cumin from imbibed embryo cultures. This method yielded a large number of shoots within short period of time (30–50 days) without any subculturing. The effects of different media, different embryo explants and various combinations of plant growth regulators (PGRs) on callus formation and shoot regeneration in cumin were investigated. Simultaneous callus formation and shoot regeneration was obtained. The best response for multiple shoot regeneration was observed on B5 medium containing 1.0 mg l^–1 BAP, 0.2 mg l^–1 NAA and 0.4 mg l^–1 IAA, with an average of 140 shoots per explant.     

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     

Rapid micropropagation of Woodfordia fruticosa (L.) Kurz (Lythraceae), a rare medicinal plant

A rapid propagation method comprising initiation of in vitro shoot tip culture from field-grown flowering plants and reculture of the nodal segments of regenerated shoots in Schenk and Hildebrandt (1972) medium was developed for Woodfordia fruticosa (L.) Kurz., a rare medicinal shrub. A medium supplement of 6-benzylaminopurine (0.2 mg.l^–1) induced high frequency (88%) development of axillary shoot buds (3.2) in 4–5 weeks. Subculture of the explants with multiple new shoots in fresh medium for 30 days yielded an even larger number (9.7) of shoots. Highest multiplication (26–35 shoots) was recorded when using culture initiation media with 0.5 mg.l^–1 each of BAP and NAA followed by subculture in 0.2 mg.l^–1 BAP. The shoot multiplication rate was further accelerated by reculturing 0.4–0.6 cm nodal segments of regenerated shoots in media with 1.0 mg.l^–1 BAP. Shoot cuttings (3.5–7.0 cm) were rooted in 0.2 mg.l^–1 IAA. Regenerated plants displayed uniform morphological, growth and flowering characteristics.Abbreviations BAP 6-benzylaminopurine - NAA naphthaleneacetic acid - IAA Indole-3-acetic acid - IBA indole-3-butyric acid - SH Schenk and Hildebrandt (1972) medium     

Micropropagation of Plumbago rosea Linn.

Multiple shoot formation from the medicinal plant Plumbago rosea Linn. was induced on callus from stem segments on Murashige & Skoog media containing auxin and cytokinin. 2,4-D (2.5 mg l^-1) and kinetin (1.5 mg l^-1) added to the media gave best callus production, while BAP (2 mg l^-1) plus NAA (1.0 mg l^-1) induced shoot formation from that callus. Numerous shoots with roots could be produced by transferring shoots to media containing IBA (1.5 mg l^-1). Regenerated plantlets were transferred to pots and 60% survived.     

Regeneration of niger (Guizotia abyssinica Cass.) CV Sahyadri from seedling explants

Root, hypocotyl and cotyledonary explants of niger (Guizotia abyssinica Cass) CV. Sahyadri were aseptically cultured on Murashige and Skoog's basal medium (MS) containing BAP and kinetin. Multiple shoot regeneration was induced from hypocotyl and cotyledonary explants while root explants produced only callus on MS medium supplemented with BAP. BAP (1 mg l^-1) was optimum for shoot regeneration. Regenerated shoots were transferred to MS medium without auxins, with auxins and with increasing concentrations of sucrose for rooting. Complete plantlets were obtained in all cases; however, 0.5 mg l^-1 NAA was the best for induction of roots. Ninety-seven per cent of the plantlets survived and completed their life cycle when transferred to natural conditions.Abbreviations BAP 6-benzylamino purine - NAA -naphthaleneacetic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid     

Large scale micropropagation ofQuercus robur L. using adenine-type cytokinins and thidiazuron to stimulate shoot proliferation

High rates of oak shoot multiplication were achieved on low salt nutrient media (BTM, WPM) supplemented with adenine type cytokinin or BAP. Low concentration of (0.2-0.6 mg 1^-1) stimulated formation of a large number of axillary shoots and their elongation. Thidiazuron in very low concentration (0.001 - 0.002 mg 1^-1) promoted shoot proliferation, in high concentration stimulated formation of large callus. More than twelve thousand micropropagated shoots were rooted in low salt agar media supplemented with low concentration of auxin (IBA or NAA 0.2 - 0.5 mg 1^-1). High rooting percentages (81 %) were obtained. Survival of the mieropropagated plantlets transplanted into soil was high (78 %). Micropropagated trees planted in the field withstood severe winter frosts without significant losses. At the end of the fifth growing season trees attained considerable size.     

Effect of abscisic acid and callus size on regeneration of american and international rice varieties

Embryogenesis and plant regeneration of Texas and international rice, Oryza saliva (L.), varieties (both indica and japonica types) were induced in culture on a regime consisting of the use of ABA or BAP in the subculture medium and small (10 mg) callus pieces on the regeneration medium. Ten 10 mg callus pieces on regeneration medium resulted in a 2- to 10-fold increase in plant regeneration over single 100 mg pieces. Plant regeneration of Texas rice cultivars (Lemont, Rico I, Rexmont and Skybonnet) and Taipei 309 was enhanced by the use of ABA in the subculture medium with a 2-fold and a 3- to 10-fold increase in plant regeneration with 2.6 mgL^–1 and 26 mgL^–1 ABA in the subculture media, respectively. Regeneration of plants from callus of IR36 and IR64 was not enhanced by ABA but by the use of BAP and Trp in the subculture medium or by 2,4-D alone. The subculture medium containing BAP and Trp produced a 5-fold increase in plant regeneration rate from IR64 callus and was equal to subculture medium containing only 2,4-D for IR36 callus. Both Lemont and IR36 were previously reported to be difficult to regenerate or non-regenerative, however, the use of ABA or BAP in the subculture medium, small callus pieces and visual selection of embryogenic callus allowed the regeneration of up to 20 and 22 plants from 100 mg of Lemont and IR36 callus, respectively.Abbreviations ABA abscisic acid - BAP benzylaminopurine - MS Murashige and Skoog - NAA napthaleneacetic acid - Trp tryptophan - 2,4-D 2,4-dichlorophenoxyacetic acid     

Establishment of an efficient and rapid method of multiple shoot regeneration and a comparative phenolics profile in in vitro and greenhouse-grown plants of psophocarpus tetragonolobus (L.) DC

An in vitro method of multiple shoot induction and plant regeneration in Psophocarpus tetragonolobus (L.) DC was developed. Cotyledons, hypocotyls, epicotyls, internodal and young seedling leaves were used as explants. MS media supplemented with various concentrations of either thidiazuron (TDZ) or N6-benzylaminopurine (BAP) along with NAA or IAA combinations were used to determine their influence on multiple shoot induction. MS media supplemented with TDZ induced direct shoot regeneration when epicotyls and internodal segments were used as explants. TDZ at 3 mg L⁻¹ induced highest rate (89.2 ± 3.28%) of regeneration with (13.4 ± 2.04) shoots per explant. MS media supplemented with BAP in combination with NAA or IAA induced callus mediated regeneration when cotyledons and hypocotyls were used as explants. BAP (2.5 mg L⁻¹) and IAA (0.2 mg L⁻¹) induced highest rate (100 ± 2.66%) of regeneration with (23.2 ± 2.66) shoots per explant. Mature plants produced from regenerated shoots were transferred successfully to the greenhouse. In a comparative study, the phenolics contents of various parts of greenhouse-grown plants with that of in vitro-raised plants showed significant variations.     

Development of in vitro procedures for regeneration of petiole and leaf expiants and production of protoplast-derived callus in Tanacetum vulgare L. (Tansy)

Tanacetum vulgare (Tansy) was established in vitro on Murashige and Skoog (MS) medium supplemented with naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP) using shoot tips and embryos. From petiole expiants 93% formed callus, and 27% produced shoots on MS medium containing 4.5 mg l^-1 NAA and BAP. NAA alone induced root formation from leaf expiants. Up to 7 ×10⁶ viable protoplasts were obtained by macerating 1 g of leaves in 0.5 % Macerozyme R-10, 1.0% Cellulase R10, and 1.0% Cellulysin. Cell division was observed 3–4 days after protoplast isolation at the optimum plating density of 0.2-0.4×10⁶ cells ml^-1. A total of 350 protoplast-derived calluses were produced on which nodules with meristematic zones developed. Roots regenerated on MS medium supplemented with BAP 3.0 mg 1^-1, NAA 2.0 mg l^-1, and 250 mg l^-1 casein hydrolysate, however no shoots have been obtained yet.Abbreviations BAP 6-benzylaminopurine - CH casein enzymatic hydrolysate - 2.4 D dichlorophenoxyacetic acid - FDA fluorescein diacetate - GA₃ gibberellic acid - IBA indole butyric acid - IPA 6-dimethylallylamino purine - KIN Kinetin - MS Murashige and Skoog medium - NAA -naphthaleneacetic acid     

Somatic Embryogenesis and Plant Regeneration from Tissue Cultures of Hyoscyamus muticus L.

Somatic embryogenesis and regeneration of plantlets was achieved In callus cultures derived from cotyledonary leaf pieces of Hyoscyamus muticus L on MS medium enriched with 2 mg/l 2,4–0 and 0.5 mg/l BAP. For embryogenesis and organogenesis varying concentrations of NAA with or without BAP were added In the medium. Organogenesis was also achieved when callus was transferred to the hormone free medium.     

Enhanced shoot regeneration from Brassica campestris by silver nitrate

Summary The morphogenetic response of Brassica campestris genotype R500 to inhibitors of ethylene biosynthesis and action was investigated. A medium containing 1.0 mg.l^–1 NAA, 2.0 mg.l^–1 BAP, and 30 or 60 M AgNO₃ significantly enhanced both the percentage shoot regeneration and the number of shoots per cotyledon expiant. Although callus proliferation occurred on hypocotyl segments, no shoots were formed in response to AgNO₃ with expiants older than five days. Cotyledons older than six days formed shoots only with AgNO₃. Cobalt chloride at 20 and 30 M increased cotyledon shoot regeneration but was inferior to AgNO₃. Hypocotyl segments were unresponsive. Salicylic acid at 25 and 50 M prevented both shoot regeneration and callusing without any obvious toxic effects. Removal of expiants from AgNO₃ after 12 days did not alter the percentage of shoot regeneration but increased the number of shoots per expiant. This response was dependent on the level of BAP. Percentage shoot regeneration and number of shoots per cotyledon explant were not affected by removal of CoCl₂. These results indicate that the poor regenerative capacity of this genotype may be related to ethylene biosynthesis or metabolism.Abbreviations NAA Naphthalene Acetic Acid - BAP 6-Benzylamino Purine - MS Murashige and Skoog Medium     

Shoot multiplication and adventitious regeneration in Sorbus aucuparia

In vitro mother plants initiated from a mature tree of Sorbus aucuparia, produced numerous propagules on a medium containing 2 μM 6-benzylaminopurine (BAP) and 0.2 μM 1-naphthaleneacetic acid (NAA). These were rooted on a medium containing 0.25 μM NAA and 0.25 μM indole−3-butyric acid. Adventitious shoots were produced on excised leaves and internodes on media containing 10 μM thidiazuron and 0.3–1.0 μM NAA. They formed by direct regeneration in the axils of leaflets of intact leaves. They also developed indirectly, from callus that developed on the rachis of intact leaves, and the cut ends of petioles and internodes. Somatic embryos were produced on cotyledons of zygotic embryos on medium containing 1 μM BAP, 1 μM kinetin, 0.5 μM NAA, 500 mg l⁻¹ casein hydrolysate and 250 mg l⁻¹ glutamine. On basal medium, 69% developed cotyledons and 20% germinated after pre-treatment at 4 °C on medium containing 30 g l⁻¹ maltose.     

Somatic embryogenesis and organogenesis inGuizotia Abyssinica

Summary Induction of somatic embryogenesis, shoot organogenesis, and subsequent plant regeneration in niger seem to be dependent on genotype, choice of explant, and composition of media growth regulators. Two distinct regeneration protocols have been developed for somatic embryogenesis and shoot organogenesis. Somatic embryogenesis was induced from epicotyls and cotyledonary explants (9 to 35%) (but not from hypocotyls and roots) in presence of 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, and 2,4,5-trichlorophenoxypropionic acid. These embryos matured in MS medium containing Kinetin plus naphthalene acetic acid (NAA), Kinetin plus Zeatin, and Kinetin plus abscisic acid (ABA). Matured embryos could be germinated on LS and MS basal media without hormones. Non-embryogenic callus initiated on Linsmaier and Skoog’s (LS) medium from cotyledons of six different genotypes produced shoots (9 to 32%) on Murashige and Skoog’s (MS) medium fortified with 6-benzylaminopurine (BAP, 0.5 mg · liter^−1), and BAP (1 mg · liter^−1) plus NAA (0.1 mg · liter^−1). These shoots were rooted with 100% frequency by using indole-3-acetic acid or NAA and transferred successfully to the soil.     

High frequency plantlets regeneration from seedling explants of Prosopis tamarugo

Callus cultures of Prosopis tamarugo Phil (Leguminosae, Sub family-Mimosoideae) were established from hypocotyls and cotyledons on MS medium supplemented with NAA (2.0 mg l^-1) and BAP (0.2 mg l^-1). Regeneration through various juvenile explants was obtained on hormone-free and high cytokinin containing Murashige and Skoog's medium. Multiple shoot buds formation was observed from the embryonic axis on MS medium incorporated with BAP (5.0 mg l^-1)). Elongation of shoot buds was observed on subsequent transfer to MS medium with BAP (1.0–2.5 mg l^-1) or without BAP. Explants containing apical meristem showed higher number of shoot formation at an early period. De novo shoot buds formation through callus morphogenesis was observed at the base of differentiated shoots on high cytokinin containing medium. All the manipulations of salt strength of MS, nitrogen, carbon, ascorbic acid and polyamines failed to induce organogenesis in isolated callus. In vitro produced shoots were rooted on MS medium supplemented with IBA or NAA singly or in combination.Abbreviations HC high cytokinin (BAP 5.0 mg l^-1) - BAP 6-benzyl amino purine - IBA indole-3-butyric acid - HF hormone free - NAA I-naphthalene acetic acid - MS Murashige & Skoog     

In vitro regeneration of chickpea (Cicer arietinum L.): Stimulation of direct organogenesis and somatic embryogenesis by thidiazuron

In vitro regeneration in chickpea (Cicer arietinum L.) was achieved by direct culture of mature seeds on Murashige and Skoog (MS) medium supplemented with either N-phenyl-N(-1,2,3-thidiazol-5-yl) urea (thidiazuron, TDZ) or N⁶-benzylaminopurine (BAP). Multiple shoots formed de novo without an intermediary callus phase at the cotyledonary notch region of the seedlings within 2 to 3 weeks of culture initiation. TDZ was found to be more effective compared to BAP as an inductive signal of regeneration. The former induced multiple shoot formation at all the concentrations tested (1 M to 100 M), although, maximum morphogenic response was observed at 10 M concentration. Addition of naphthaleneacetic acid (NAA) alone or in combination with BAP to the MS medium failed to invoke a similar response. When the TDZ supplemented medium was amended with L-proline, the resultant regenerants were mostly somatic embryos. Histological investigations confirmed the switch in the regeneration pathway from directly formed adventitious shoots to embryogenesis. For obtaining plantlets, adventitious shoots were rooted on MS medium supplemented with 2.5 M NAA; somatic embryos were germinated and established on MS medium. Normal plants were regenerated from both adventitious shoots and somatic embryos and transferred to soil.Abbreviations BAP 6-benzylaminopurine - MS Murashige and Skoog [14] basal medium - NAA naphthaleneacetic acid - TDZ thidiazuron [N-phenyl-N(-1,2,3,-thidiazol-5-yl)-urea]     

In vitro culture of petioles and intact leaves of sugar beet (Beta vulgaris)

Methods are described for obtaining explants which produce adventitious shoots, for subsequent stimulation of rooting and then transplanting using six commercial sugar-beet cultivars. The rate of adventitious shoot regeneration from petioles or intact leaf explants was affected by the source of donor plants, cytokinin type (BAP or Kin) and concentration and cultivar. Increasing the sucrose concentration of the medium from 3% to 5% or 8% had no apparent effect. Adventitious shoots could be produced directly from callus formed on the base of the petioles. In general adventitious shoots were produced on either the concave surface of the petiole or from the callus, occasionally simultaneously on both, and on the convex surface of the petiole in intact leaf explants. The highest rooting rate with 3% sucrose and 1.0 mg l^–1 NAA was obtained using half-strength MS medium. There was considerable variation in the propagules from petioles or callus indicating that this system may provide valuable somaclonal variation.Abbreviations BAP benzylaminopurine - IBA indole-3-butyric acid - GA₃ gibberellic acid - MS Murashige and Skoog medium - NAA naphthaleneacetic acid Author for correspondence