Somatic embryogenesis and plant regeneration of squash Cucurbita pepo L cv. YC 60

Plant regeneration from tissue cultures of summer squash, Cucurbita pepo L., cv. YC60, has been observed. Somatic embryos organized from shoot apex derived callus cultured on Murashige and Skoog (MS) medium supplemented with 1.2 mg/l 2,4,5-trichlorophenoxyacetic acid, 0.8 mg/l benzylaminopurine, and 0.1 mg/l kinetin. Embryos developed into plantlets by transfer of immature somatic embryos to MS medium with 0.05 mg/l NAA and 0.05 mg/l kinetin. Regenerated plants appeared morphologically normal and set fruits with seeds which could germinate normally.Abbreviation BAP 6-benzylaminopurine - 2,4-D 2, 4dichlorophenoxyacetic acid - IAA indole-3-acetic acid - KN kinetin - NAA -naphthyleneacetic acid - MS Murashige and Skoog - 2,4,5-T 2, 4,5-trichlorophenoxyacetic acid     

Callus initiation and plant regeneration from inflorescence primordia of the intergeneric hybrid Agropyron repens (L.) Beauv.xBromus inermis Leyss. cv. nanus on a modified nutritive medium

Plant regeneration from callus of intergeneric hybrid Agropyron repens (L.) Beauv. x Bromus inermis Leyss cv. nanus (AGROMUS) was carried out on a new culture medium designated medium-F. Within 21 days of the plating of inflorescence primordia the initiated callus showed globular structures. From the 21st day of culture, one step plant regeneration occurred on the callus without subculture. The new basal medium reported in this work was effective in callus initiation and plant regeneration of the hybrid AGROMUS by (i) the reduction of the total ion strength (2.6 g/l, 22.5 mM) of macroelements compared to MS (4.5 g/l,45.2 mM), (ii) the use of NH₄NO₃ as the sole N-source, and (iii) the application of KH₂PO₄ at an 8 times higher concentration (1160 mg/l,8.5 mM) when compared to the Murashige and Skoog medium composition. This medium provided a 2 to 10 fold reduction in the 2,4-dichlorophenoxyacetic acid supplement needed for the callus initiation and one step plant regeneration after a gibberellic acid (2 mg/l, for 5 days) pretreatment of tillers. The regenerated plantlets were subcultured in multi-shoot culture and potted in soil to grow for further analysis.Abbreviations AA amino acid medium (Müller and Grafe 1978, Toriyama and Hinata 1985) - B5 Gamborg et al. (1968) medium - 2,4-D 2,4-dichlorophenoxyacetic acid - GA₃ gibberellic acid - MS Murashige and Skoog (1962) medium - NAA naphthaleneacetic acid - N6 Chu et al. (1975) medium - SH Schenk and Hildebrandt (1972) medium - 2,4,5-T 2,4,5-trichlorophenoxyacetic acid     

Plant regeneration from cotyledons of niger

Callus initiation from seedling explants of niger (Guizotia abyssinica Cass) cv. Ootacamund was found to be better on LS medium containing kinetin (1.4 M) plus 2,4-dichlorophenoxyacetic acid (9 M) than its analogues. Embryoids were induced directly from cotyledons on LS medium supplemented with 2,4,5-trichlorophenoxyacetic acid and 2,4,5-trichlorophenoxypropionic acid. When cotyledon-derived callus was subcultured onto medium with 10.7 M naphthalene-acetic acid and 2.3 M kinetin, embryogenesis was observed. Multiple shoots were obtained from cotyledonary explants in presence of MS medium containing 4.4 M benzyladenine and 11.4 M indoleacetic acid. Regenerated plants that were transferred to pots and grown to maturity were morphologically normal and fertile.Abbreviations NAA naphthaleneacetic acid - IAA indoleacetic acid - BA benzyladenine - GA₃ gibberellic acid - 2,4-D 2,4-dichlorophenoxyacetic acid - 2,4,5-T 2,4,5-trichlorophenoxypropionic acid - 2,4,5-TP 2,4,5-trichlorophenoxypropionic acid - ABA abscisic acid     

Zeatin-induced shoot regeneration from immature chickpea (Cicer arietinum L.) cotyledons

For the purpose of developing an in vitro regeneration system for chickpea (Cicer arietinum L.), an important food legume, immature cotyledons approximately 5 mm long were excised from developing embryos and cultured on B5 basal medium supplemented with 1.5% sucrose and various growth regulator combinations. Only non-morphogenic callus was formed in response to concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), naphthaleneacetic acid (NAA) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) previously reported to induce somatic embryogenesis on immature soybean cotyledons. However, 4.6, 13.7, and 45.6 M zeatin induced formation of white, cotyledon-like structures (CLS) at the proximal end of immature cotyledons placed with adaxial surface facing the agar medium. No morphogenesis, or occasional formation of fused, deformed CLS, was observed when zeatin was replaced with kinetin or 6-benzyladenine, respectively. The highest response frequency, 64% of explants forming CLS, was induced by 13.7 M zeatin plus 0.2 M indole-acetic acid (IAA). Within 20–40 days culture on zeatin, shoots formed at the base of CLS on approximately 50% of CLS-bearing explants, and proliferated upon subsequent transfer to basal medium with 4.4 M BA or 4.6 M kinetin. This regeneration system may be useful for genetic transformation of chickpea.     

Improved shoot regeneration system through leaf derived callus and nodule culture of Sansevieria cylindrica

Long-term culture establishment and efficient in vitro regeneration protocol for Sansevieria cylindrica Bojer ex Hook was developed using leaf derived callus and nodule culture. Profuse callus induction on leaf discs was achieved on Murashige and Skoog (MS) medium supplemented with 10 μM indole-3-butyric acid (IBA), while a high frequency of nodulation was induced on 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) containing media. Shoot regeneration ability from cultured tissues occurred at varying degrees on all media. Through callus culture a maximum of 17.6 ± 0.14 shoots per culture was formed on medium containing 5μM 6-benzyladenine (BA) and 2 μM α-naphthaleneacetic acid (NAA). Among nodule cultures, the 2,4-D generated nodules were more proliferative and regenerative as compared to 2,4,5-T induced nodules and a maximum of 25 ± 0.16 shoots per culture was produced on a medium containing 5 μM BA plus 1 μM NAA. The regenerated shoots were successfully rooted on a semi-solid half strength MS medium containing 5 μM IBA with an average root number 3.5 ± 0.18 and root length 6.5 ± 0.14 cm. The regenerative ability of callus tissues was steady upto one year, while the nodules retained the totipotency to regenerate on optimal medium even after 3 years of subculturing. The histological sections of nodules confirm the typical anatomy exhibiting the vascular elements in bundles with well demarcated cortex and epidermal covering.     

Long-duration,high-frequency plant regeneration from cereal tissue cultures

By visual examination of calli derived from germinating seeds of wheat, oats, rice, proso millet, and pearl millet it has been possible to visually select embryogenic (E) callus which, on transfer to a regeneration medium, forms plants an average of 33 times more frequently than non-embryogenic (NE) callus of equal mass. Embryogenic callus consists of small isodiametric cells averaging 31 m in diameter; NE callus consists of long tubular cells averaging 52 m in width and 355 m in length. Production of E callus is in many cases promoted by media containing 2,4-di- or 2,4,5-trichlorophenoxyacetic acid (2,4-D or 2,4,5-T) plus indole-3-acetic acid or tryptophan+kinetin. Production on NE callus is promoted by media containing 2,4-D or 2,4,5-T alone. As a result of initial experiments to optimize both media for E callus production and media for plant regeneration, callus derived in six passages from an average of 26 seeds could produce about 1,000 regenerated plants.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - 2,4,5-T 2,4,5-trichlorophenoxyacetic acid - IAA indole-3-acetic acid - Kin kinetin - Trp L-tryptophan - E embryogenic - NE non-embryogenic     

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     

Influence of photoperiod and medium formulation on peanut somatic embryogenesis

Somatic embryos were produced from peanut (Arachis hypogaea L.) immature zygotic cotyledons. Comparisons were made of the level of -naphthaleneacetic acid during induction, nitrogen formulation of the medium, and photoperiod. Over 70% embryogenesis was obtained regardless of NAA level used. Percent embryogenesis and number of embryos were markedly lower in explants induced on NAA compared to 2,4-D. Embryo production was not greatly affected by either the use of Murashige & Skoog versus Finer & Nagasawa salts or light versus dark culture conditions. However, embryo morphology was noticeably affected by photoperiod. Embryos produced under a 16 h photoperiod were tough, woody and difficult to separate for subsequent germination and conversion. Those produced under a 0-h photoperiod were succulent and pliable.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - NAA -naphthaleneacetic acid - MS Murashige & Skoog (1962) - B5 Gamborg et al. (1968) - picloram 4-amino-3,5,6-trichloropicolinic acid - FN Finer & Nagasawa (1988) - 2,4,5-T 2,4,5-trichlorophenoxyacetic acid     

Regeneration of plants from primary leaves of cowpea

Plants were regenerated from the in vitro cultured explants of primary leaves of cowpea (Vigna unguiculata L. Walp). Primary leaves, including the intact petiole, were excised from three-day-old seedlings and cultured on Gamborg's B5 basal medium containing 8×10^–7 M 2,4,5-trichlorophenoxyacetic acid, 1×10^–2 M L-glutamine and 1×10^–4 M adenine sulfate. Callus formed at the petiole end. Prolific shoot regeneration occurred when this callus was transferred to B5 basal medium containing 5×10^–6 M 6-benzyl-aminopurine (BAP). Regenerated shoots rooted in growth-regulator-free B5 basal medium and were established in soil.Abbreviations BAP 6-benzylaminopurine - IAA indole-3-acetic acid - NAA 1-napthalene acetic acid - 2,4,5-T 2,4,5-trichloro-phenoxyacetic acid     

Adventitious shoot regeneration from leaf, stem and root explants of commercial cultivars of Gentiana

Several culture conditions were examined for promoting efficient plant regeneration from explants of Gentiana. Adventitious shoot regeneration from leaf explants of cv. WSP-3 was very superior on MS medium, compared to B5 medium, supplemented with four cytokinins (TDZ, 4PU-30, BA and zeatin). An auxin / cytokinin combination was required for regeneration. TDZ was the most effective cytokinin, while NAA was more effective than IAA or 2,4-D. Optimum conditions for regeneration from explants (leaf, stem and root) of cv. WSP-3, evaluated in terms of regeneration frequency and number of regenerated shoots per explant, were TDZ and NAA in combination, 5–10 mg/l and 0.1 mg/l for leaf and stem explants, and 10 mg/l and 1 mg/l for root explants, respectively. Application of these conditions to eight other commercial cultivars resulted in 30–100% regeneration from leaf explants. The number of chromosomes in each of ten regenerated plants of each cultivar was diploid, 2n=26. Shoots regenerated in vitro were rooted in phytohormone-free medium and transferred to soil.Abbreviations MS medium Murashige and Skoog's medium (Murashige and Skoog 1962) - B5 medium Gamborg B5 medium (Gamborg et al. 1968) - BA 6-benzylaminopurine - TDZ N-phenyl-N'-1,2,3-thiadiazol-5-yl urea - 4PU-30 N-(2-chloro-4-pyridyl)-N'-phenylurea - 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indole-3-acetic acid - NAA 1-naphthaleneacetic acid     

Application of the disk method: responses to growth regulators

The paper disk method of screening several plant growth regulators was evaluated. Leaf explants ofVigna unguiculata (L) Walp. were placed on solidified Murashige and Skoog's minimal organics medium containing 0.5 mg/l nicotinic acid. Hormones were tested, singly and in combinations, on paper disks in large Petri plates (150×20 mm). Hormones tested were 2,4-D (2,4-dichlorophenoxyacetic acid), 2,4,5-T (2,4,5-trichlorophenoxyacetic acid), IAA (indole-3-acetic acid), IBA (indole-3-butyric acid), picloram (4-amino-3,5,6-trichloropicolinic acid), dicamba (3,6-dichloro-2-methoxybenzoic acid), BA (6-benzyladenine), 2iP (2-isopentenyl adenine), and kinetin [6-(furfurylamino)-purine]. Root formation was stimulated by IAA and IBA; dicamba, picloram, 2,4-D, and 2,4,5-T stimulated callus formation. All cytokinins tested suppressed root formation. Dicamba in combination with either 2iP or kinetin induced the greatest callus formation. Root formation was optimal with kinetin and either IAA or IBA. The disk method provided a rapid, nonquantitative evaluation of callus and root formation from leaf disks.     

Embryoid and plantlet formation from leaf segments of Dactylis glomerata L.

Summary The purpose of this investigation was to demonstrate callus induction and plantlet formation from cultured leaf segments of 12–15 week-old Dactylis glomerata L. (orchardgrass) plants. Flat half-leaf sections, approximately 2–3 mm square, from the three innermost (youngest) leaves were isolated and individually plated serially beginning at the leaf base on a solid SH medium containing 30 M of 3,6-dichloro-oanisic acid (dicamba). Callus formed on leaf sections from all 50 plants used in the study. After transfer to SH medium with 1 M dicamba, plantlets formed from leaf sections of 9 of the 50 plants. In most cases plantlets formed from embryogenic callus but in a few cases embryoids formed directly on the leaf surface without an intervening callus state. These developed into plantlets when transferred to low auxin medium. The response for both callus and plantlet formation decreased with increasing distance both spatially and temporally from the shoot apex. Histological examination of embryogenic callus revealed the presence of non-zygotic embryos in various stages of development. The results provide further support for compentency (if not totipotency) of Gramineae leaf cells.     

Shoot regeneration from stem and leaf callus of Eucalyptus tereticornis

Adventitious shoots were obtained from leaf and stem callus of Eucalyptus tereticornis SM. Callus was induced on B5 medium with 0.1 mg/l benzyladenine (BA) and 3 or 5 mg/l naphthalene acetic acid in the dark. Shoot initiation occurred on modified Woody Plant medium (mWP) containing 0.5 mg/l BA, 500 mg/l polyvinylpyrrolidone and 10% (v/v) coconut milk. Multiple shoots were also regenerated directly from hypocotyl segments of 4 to 6 week old seedlings on B5 medium with 0.5 mg/l BA. Regenerated shoots could be rooted with 100% efficiency on mWP medium containing 0.5 mg/l indolebutyric acid and transferred to soil in the greenhouse. Suspension cultures were obtained from the callus using B5 medium with 0.5 mg/l 2,4-dichlorophenoxyacetic acid. Callus clumps grew from less than 1 mm to 4–6 mm in diameter within two weeks on transfer to shoot regeneration medium but failed to form shoots or somatic embryos.Abbreviations BA Benzyladenine - 2,4-D 2,4-dichlorophenoxyacetic acid - IBA Indolebutyric acid - NAA Naphthaleneacetic acid - PVP Polyvinylpyrrolidone - mWP modified Woody Plant medium Scientific Contribution No. 1689 from New Hampshire Agricultural Experiment Station.     

Effects of auxins,cytokinins, carbohydrates and amino acids on somatic embryogenesis induction from shoot apices of pea

Studies were conducted to test the effects of various auxins, cytokinins, carbohydrates and amino acids on somatic embryogenesis from shoot apices of pea (Pisum sativum L.) cultured on a sole medium. Picloram (4.5 M) and 4-chlorophenoxyacetic acid (45 M) were the most effective auxins. Addition of cytokinins (benzyladenine, zeatin, kinetin) to auxin-containing medium reduced embryo production. Amino acids (glutamine, alanine, proline) did not improve somatic embryogenesis. Carbohydrate seemed to be a critical factor. Embryogenic efficiency and embryo development were promoted by high carbohydrate concentration. The best results were obtained with fructose (252–504 mM); the number of somatic embryos per cultured explant was 3- to 4-fold higher compared to the control (84 mM sucrose). From these results, an optimized induction medium is proposed.Abbreviations BA benzyladenine - 4-CPA 4-chlorophenoxyacetic acid - 2,4-d 2,4-dichlorophenoxyacetic acid - NAA 1-naphthaleneacetic acid - 2,4,5-T 2,4,5-trichlorophenoxyacetic acid - MS Murashige & Skoog - EE embryogenic explants - G globular somatic embryos     

Callus production,regeneration and evaluation of plants from cultured inflorescences of tall fescue (Festuca arundinacea Schreb.)

Twenty genotypes (individual plants) of Kentucky 31 tall fescue (Festuca arundinacea Schreb., 2n=6x=42) were evaluated to determine regeneration response, and meiotic and isozyme changes in the regenerants. Six genotypes (K8, K16, K25, K27, P3 and P13) were selected for study of efficiency in producing calli and regenerating plants. Panicle pieces (3569) were plated on Schenk & Hildebrandt medium with one of three auxins, 2,4-D (2.0 mg 1^-1), pCPA (3.8 mg 1^-1) or 2,4,5-T (2.5 mg 1^-1). Square-root transformed data were analysed as a completely randomized 6×3 factorial with genotype and auxin as the main effects. F-protected means were compared by the Waller-Duncan K-ratio T test. Genotype K8 produced significantly more calli per panicle piece (88/877), whereas genotype K25 regenerated significantly more plantlets per panicle piece (58/214) than the other genotypes. Callus production was significantly higher using 2,4-D (102/1244 calli per piece) than pCPA or 2,4,5-T. The type of auxin did not have a statistically significant effect on plant regeneration, which suggested that genotype was the most important variable. Twelve of the 210 regenerants were albino. Cytological evaluation of 95 green regenerants showed that all plants had 21 bivalents and pollen stainability ranged from 43.0–98.4%, which suggested all plants were male fertile. Zymograms of these 95 regenerants for ACPH, ADH, GOT, MDH, 6-PGD, PGI and SOD showed no differences from that of the parental genotype, which suggested that the green plantlets regenerated from somatic tissue.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - pCPA parachlorophenoxyacetic acid - 2,4,5-T 2,4,5-trichlorophenoxyacetic acid - ACPH acid phosphatase - ADH alcohol dehydrogenase - GOT glutamate oxaloacetate transaminase - MDH malate dehydrogenase - 6-PGD 6-phosphogluconate dehydrogenase - PGI phosphoglucoisomerase - SOD sulfoxide dismutase     

Direct shoot regeneration from foliar explants of an epiphytic orchid,Acampe praemorsa (Roxb.) Blatter and McCann

An efficient and reproducible procedure is described for the large-scale propagation of an epiphytic orchid,Acampe praemorsa (Roxb.) B latter and McCann using foliar explants. Shoot buds were induced in basal parts of foliar explants on Murashige and Skoog medium supplemented with N⁶-benzyladenine (BA), kinetin (Kn) or thidiazuron (TDZ), the latter being most effective at 1.0 mg/1. Shoots formed to a TDZ-containing medium elongated following transfer to a substrate supplemented with 2.0 mg/l 1-naphthaleneacetic acid (NAA) and 0.5 mg/1 BA. NAA at lower concentrations had no beneficial effects on shoot regeneration, whether added to the medium along with BA, Kn or TDZ. However, it promoted shoot elongation and leaf expansion. Higher concentrations of NAA suppressed shoot regeneration. The frequency of shoot regeneration was greatly influenced by the developmental stage and orientation of the leaf. Shoots regenerated from the foliar explants were rooted successfully on MS medium containing 1.0 mg/l indole-3-butyric acid. The plantlets were acclimated and eventually transferred to a garden.Abbreviations BA N⁶-Benzyladenine - IAA Indole-3-acetic acid - IBA Indole-3-butyric acid - Kn Kinetin - MS Murashige and Skoog (1962) medium - NAA 1-Naphthaleneacetic acid - TDZ Thidiazuron (N-phenyl-N-1,2,3-thiadiazol-5-ylurea)     

Plant regeneration from mesocotyl callus of Hordeum vulgare L.

Callus tissue was induced on barley mesocotyl explants of germinated seven-day-old seedlings on MS medium supplemented with 2,4-D or 2,4,5-T in high concentrations. Two morphologically different tissue cultures were maintained in vitro for a long time: a callus tissue without organogenesis and a culture with high rhizogenic capacity. Shoots and plantlets were generated when the auxin-media induced callus was transferred to medium supplemented with 3 M TIBA. In 62% of cultures, during the first five subcultures, four to twentyeight plants per single mesocotyl were obtained. Some cultures produced shoots even in the 9th subculture, being in culture for nearly 14 months. The largest number of plants obtained per one mesocotyl was forty. Plantlets rooted well on MS with 5.7 M IAA and survived transplantation to soil in high percentages.Abbreviations IAA indole-3yl-acetic acid - BA 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid - 2,4,5-T 2,4,5-trichlorophenoxyacetic acid - TIBA 2,3,5-triiodobenzoic acid - MS Murashige and Skoog (1962) medium     

Rapid mass propagation of Tylophora indica Merrill via leaf callus culture

An efficient protocol has been developed for rapid mass propagation of Tylophora indica from leaf derived callus. Optimal callus was developed from leaf explants on Murashige and Skoog (MS) basal medium supplemented with 10 2,4,5-T. Adventitious shoots were regenerated (85%) from the surface of the callus on MS medium supplemented with 5 M Kinetin. Individual elongated shoots were rooted on half-strength MS medium containing 0.5 M IBA. Regenerated plantlets with well developed shoots and roots were successfully transferred to soil. The study demonstrated a dedifferentiated callogenic propagation route via adventitious shoot development in T. indica, which could be useful for large scale multiplication of this endangered medicinal plant.     

Enhanced somatic embryogenesis and plant regeneration in leaf explant cultures of Ostericum koreanum on medium of varying pH

The leaf explants of Ostericum koreanum were cultured on MS medium supplemented with 5.37 M NAA and 0.44 M BA and did not need transfer to growth regulator–free medium for somatic embryogenesis. The pH level of medium dropped after autoclaving and at the beginning of explant culture, then rose back to the normal pH level of medium. The low pH level of medium, pH 4.0 or 4.3, before autoclaving rose to pH 5.2 or 5.3 and pH 6.1 or 6.2 after the 1 and 8 weeks from culture initiation, respectively, and this level was variable around pH 5–pH 6 during culture period. The explants were exposed to low pH for only several days at the early period of culture. On medium of pH 4.3, the production of somatic embryos was enhanced to six times in comparison with that on medium of pH 5.8. The average regeneration rate of total somatic embryos produced on medium of low pH was over 10% higher than that at pH 5.8. The regeneration of cup-shaped embryos was improved from 33% on medium of pH 5.8 to 67% on medium of pH 4.3. Therefore, the production and regeneration of somatic embryos were enhanced by the temporary exposure of leaf explant to medium of low pH, even though somatic embryogenesis substantially occurred on medium of nearly routine pH.     

Effect of genotype,explant and medium onin vitro regeneration of red pepper

In vitro plant regeneration was achieved inCapsicum praetermissum, C. baccatum andC. annuum cvs. G4, Bhiwapuri Sweet pepper, Cayenne pepper and Hybrid pepper. Shoots were induced from hypocotyl, cotyledon and leaf explants on Murashige and Skoog medium supplemented with 5.7 M indoleacetic acid (IAA)+13.3 M benzyladenine (BA); 22 M BA; and 44 M BA. Analysis of variance revealed that the most significant effect on shoot regeneration was due to the explant and it accounted for 56.3% of total variation observed. The genotype x explant effect on regeneration was minor relative to all other 2- and 3-way interactions because leaf explants consistently regenerated more shoots than hypocotyls or cotyledons in all the genotypes and thereby reduced the variation among the genotypes. Explant x medium interaction revealed that 22 M BA was the best growth regulator supplement in regeneration medium for optimal shoot regeneration from leaf explants. Rooting of regenerated shoots was achieved on 5.7 M IAA-containing medium, and the rooting response was better from shoots induced on medium fortified with 5.7 M IAA plus 13.3 M BA. Complete plantlets with diploid chromosome number (2n=2x=24) were transferred to soil and 60–70% of these plantlets survived and grew well.