Axillary shoot induction and plant regeneration in Plantago ovata Forssk

Axillary shoot induction and plant regeneration were obtained in Plantago ovata. The optimum medium for inducing axillary shoots was Murashige & Skoog (MS) medium [5] supplemented with 4.6 M kinetin and 0.05 M NAA. Rooting of shoots was best on half-strength MS medium containing 5.0 M IBA and 0.05 M kinetin. The regenerated plants were similar to the control plants in karyotypic and phenotypic details.     

Enhanced development of somatic embryos of Plantago ovata Forsk. By additives

Summary Plantago ovata Forsk (commonly known as Isabgul) is an economically important medicinal plant. In the present investigation, in vitro plant regeneration of P. ovata was attempted through somatic embryogenesis. Casein hydrolysate and coconut water were used in different concentrations in Murashige and Skoog medium along with 1-naphthaleneacetic acid and N⁶-benzyladenine to increase the amount of callus and number of somatic embryos. Light and scanning electron microscopic studies followed the developmental stages of embryo formation. Results indicated that optimum concentrations of casein hydrolysate and coconut water are useful for promoting the growth of embryogenic cultures. However, a supra-optimal dose of casein hydrolysate and coconut water induced polyphenol synthesis and caused browning of callus and also eventual death of embryos. The use of additives such as coconut water and casein hydrolysate promotes large-scale production of P. ovata through in vitro somatic embryogenesis.     

In Vitro Radiation Induced Alterations in Heavy Metals and Metallothionein content in Plantago ovata Forsk

Proton Induced X-ray emission (PIXE) and fluorescence-activated cell sorting (FACS) have been used to study the effects of gamma irradiation on heavy metal accumulation in callus tissue of Plantago ovata-an important cash crop of India. PIXE analysis revealed radiation-induced alteration in trace element profile during developmental stages of the callus of P. ovata. Subsequent experiments showed antagonism between Fe and Cu and also Cu and Zn and synergistic effect between Fe and Zn. FACS analysis showed significant induction of the metallothionein (MT) protein following gamma-irradiation, and maximum induction was noted at the 50-Gy absorbed dose. This indicated a progressive increment of MTs as a measure for protection against gamma-rays, to combat alteration in the homeostasis of heavy metals like Fe, Cu, Zn, and Mn.     

Callus initiation and regeneration capacities in Brassica species

In order to know the genetic differences of de- and redifferentiation capacities, seven Brassica species (B. campestris, B. nigra, B. oleracea, B. hirta, B. carinata, B. juncea and B. napus) were cultured in vitro, and their response to the medium supplemented with various combinations of auxin and cytokinin hormones was compared. Important factors for callus initiation were shown to be auxin and species. Calli were induced most frequently in Murashige and Skoog (MS) medium with 1.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), whereas -naphthaleneacetic acid (NAA) induced preferentially roots at a concentration of 2 to 5 mg/l. Callus-, root- and shoot-forming capacities from explanted cotyledon tissues were significantly different among the seven Brassica species. Calli derived from cotyledons and hypocotyls of seven species were transferred to MS media with 20g/l sucrose, 0 to 0.1 mg/l NAA and 0 to 4 mg/l kinetin to compare their regeneration capacities. Among the seven species tested, B. napus (2n=4x=38, genome AACC) had the highest shoot forming capacity (20.0%). Other amphiploid species, B. carinata (2n=4x=34, BBCC) and B. juncea (2n=4x=36, AABB) formed shoots at low frequencies (2.8% and 1.2%, respectively). A diploid species, B. oleracea (2n=2x 18, CC) also showed high shoot formation (10.2% on average). This result suggests that the gene(s) controlling shoot formation may be localized in the C genome. Differences were also found among varieties and cultivars within a species. One of the cultivars, Siberian kale (B. oleracea var. acephala) gave about 50% shoot formation. This kale was shown cytologically to be an autotetraploid (2n=4x=36, CCCC), thus probably possessing a double set of the shoot-forming gene(s).     

Callus growth and plant regeneration in diverse cultivars of cucumber (Cucumis sativus L.)

The growth and differentiation of callus tissues derived from cotyledons of ten cultivars ofCucumis sativus L. were investigated. Cotyledonary explants from all ten cultivars formed callus tissue on Murashige and Skoog (MS) medium supplemented with 0.5 M 2,4-dichlorophenoxyacetic acid and 5 M 6-benzylaminopurine. Fresh weight of the callus tissues averaged 1 to 8 g per flask after five weeks of culture. Shoot development was achieved in three cultivars, Hukchinju, Manchoonchoungjang and Seoul, on MS medium supplemented with 0.5 M -naphthaleneacetic acid and 5 M 6-benzylaminopurine. Reducing the 6-benzylaminopurine concentration to 0.01 M resulted in root formation on callus tissues and on shoots transferred to this medium. All cultivars gave the same response in tests of root formation, but shoot regeneration from callus culture of cucumber cotyledons was dependent on genotype with cultivar Manchoonchoungjang exhibiting the best shoot differentiation capability among the genotypes examined. Examination of mitotic metaphase from the regenerants revealed that all were tetraploid.     

Callus initiation and plant regeneration in ragi (Eleusine coracana Gaertn.)

Callus was successfully initiated on root, mesocotyl and leaf base segments of 3- to 4-day-old seedlings of ragi (Eleusine coracana Gaertn.). 2,4-D along with casein hydrolysate for Murashige and Skoog's basal medium was found to be most effective for callus initiation and maintenance. Mesocotyl and leaf base tissue derived calli gave shoot buds in medium in which the 2,4-D concentration was lowered.     

Impact of bio-fertilizers and different levels of cadmium on the growth,biochemical contents and lipid peroxidation of Plantago ovata Forsk

Plantago ovata Forsk. (isabgol) is a valuable medicinal plant; its seeds and shell have a significant role in pharmacy as a laxative compound. Increasing soil contamination with cadmium (Cd) is one of the major concerns and is responsible for toxic effects in plants. This investigation was aimed to analyze the role of biofertilizers in alleviation of cadmium stress, given at the rate of 0, 50, and 100 mg kg⁻¹ of soil. The plants of isabgol, were grown in pots with and without application of AM fungi and Azotobacter (alone and combination). Cadmium showed negative effect on growth and biochemical component whereas proline and MDA content increase with increasing cadmium concentration. Addition of bio-fertilizer showed better growth and higher pigment concentration under cadmium stress as compared to the control. The dual inoculation of AM fungi and Azotobacter was found to be the best in reduction of cadmium stress and promotion of growth parameters.     

Callus induction and plant regeneration from shoot portions of mature embryos of high tannin sorghums

Callus and plant regenertion were induced from shoot portions of mature embryos (dry seeds) of five high tannin Sorghum bicolor (L.) Moench cultivars. The explants were cultured on Murashige and Skoog medium with altered concentrations of 5 salts, supplemented with 150 mg/L L-asparagine, 5mg/L 2,4-Dichlorophenoxyacetic acid and 0.05mg/L kinetin. Calli which were yellow and globular were formed with 70–90% frequencies. The subculture medium which gave best results was MS with 2mg/L 2,4-Dichlorophenoxyacetic acid and 0.5mg/L kinetin. Plants were regenerated on MS medium supplemented with 150mg/L L-asparagine and 0.2mg/L kinetin with regeneration frequencies of 11–48%.Abbreviations 2,4-D dichlorophenoxyacetic acid     

Callus culture of Coronilla varia L. (crownvetch): plant regeneration through somatic embryogenesis

Callus culture and plant regeneration through somatic embryogenesis have been obtained in Coronilla varia. Media used were UM (25) supplemented with 2 mg/l 2,4-D followed by subculture on MS (18) containing 1 mg/l 2-iP and 0.1 mg/l IAA. Embryoids developed into complete plantlets on filter paper saturated with hormone-free MS medium.     

Callus formation and plant regeneration from tubercles of Coryphantha elephantidens (Lem.) Lem.

Summary Callus cultures were established from pith tissue of Coryphantha elephantidens (Lem.) Lem. on Murashige and Skoog (MS) basal medium supplemented with 9.05 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.3 μM kinetin. Highest shoot regeneration frequency was observed on a medium containing 6.9 μM kinetin and 2.3 μM 2,4-D under 30 μE m⁻² s⁻¹ light intensity with a 16-h photoperiod. Calluses retained organogenic potential throughout several passages of subculture (18 mo.). Shoots were rooted on MS medium without plant growth regulators. All (100%) plantlets transplanted to soil survived acclimatization. Regenerated plants showed good overall growth and were morphologically similar to the mother plants.     

The gel-forming polysaccharide of psyllium husk (Plantago ovata Forsk)

The physiologically active, gel-forming fraction of the alkali-extractable polysaccharides of Plantago ovata Forsk seed husk (psyllium seed) and some derived partial hydrolysis products were studied by compositional and methylation analysis and NMR spectroscopy. Resolving the conflicting claims of previous investigators, the material was found to be a neutral arabinoxylan (arabinose 22.6%, xylose 74.6%, molar basis; only traces of other sugars). With about 35% of nonreducing terminal residues, the polysaccharide is highly branched. The data are compatible with a structure consisting of a densely substituted main chain of beta-(1-->4)-linked D-xylopyranosyl residues, some carrying single xylopyranosyl side chains at position 2, others bearing, at position 3, trisaccharide branches having the sequence L-Araf-alpha-(1-->3)-D-Xylp-beta-(1-->3)-l-Araf. The presence of this sequence is supported by methylation and NMR data, and by the isolation of the disaccharide 3-O-beta-D-xylopyranosyl-L-arabinose as a product of partial acid hydrolysis of the polysaccharide.     

Callus induction and high-frequency plant regeneration from hypocotyl and cotyledon explants of Arctium lappa L.

Summary This study describes a protocol for plant regeneration from cultured seedling explants of Arctium lappa. Hypocotyls and cotyledons of A. lappa were induced to form callus by culturing on Murashige and Skoog (MS) medium supplemented with 2.0mg l^−1 2,4-dichlorophenoxyacetic acid and 0.5–2.0 mg l^−1 benzyladenine (BA). Formation of adventitious buds could be induced from calluses or explants directly by culturing on MS medium containing 1.0–2.0 mg l^−1 α-naphthaleneacetic acid (NAA) and 0.5–2.0 mg l^−1 BA. These regenerated shoots were rooted on MS medium with 1.0 mg l^−1 indole-3-butyric acid or indole-3-acetic acid in combination with 1.0 mgl^−1 NAA. The regenerated plants acclimatized in soil were normal morphologically and in growth characters. They flowered and set seeds in the following year after acclimatization.     

Callus induction and plant regeneration from mature embryos of sunflower

Callus development and efficient shoot and root organogenesis were obtained from five different sunflower (Helianthus annuus L.) genotypes: Trakya 80, Trakya 129, Trakya 259, Trakya 2098, and Viniimk 8931, which are commercially important for Turkey. Plant tissue culture systems were established on Murashige and Skoog (MS) media supplemented with various plant growth regulators using mature embryos of sunflower. For callus induction MS + 1 mg/l 2,4-D, for shoot regeneration MS + 1 mg/l benzyladenine and 0.5 mg/l α-naphthaleneacetic acid were used. Callus induction ratios were around 80–92% in all tested genotypes. The Trakya 259 genotype gave the best shoot regeneration response (44%). All regenerated shoots were rooted on MS medium supplemented with 1 mg/l indolyl-3-butyric acid and on MS medium without any hormones. Mature embryos could be an alternative source for indirect plant regeneration and gene transfer systems for different sunflower genotypes. Published in Russian in Fiziologiya Rastenii, 2006, Vol. 53, No. 4, pp. 621–624. The text was submitted by the authors in English.     

骆驼蓬的组织培养及植株再生

以骆驼蓬(Peganum harmala L)无菌苗下胚轴切段为材料,在不同的培养基上进行愈伤组织的诱导,发现在MS基本培养基附加2．0mg/L 2,4—D、0．5mg／L 6—BA和3％蔗糖时,可100％的诱导出愈伤组织。愈伤组织在附加2．0mg／L 6—BA、0．5mg／L NAA、500mg／L CH和3％蔗糖的MS培养基上诱导出丛生芽,进而发育成苗,苗的分化频率在30％左右。分化苗或其茎切断在附加0．2mg／L IBA、0．2mg/L NAA和3％蔗糖的l／2MS培养基上出现根的分化,分化频率在90％以上。再生植株经炼苗后移栽成活,成活率在80％以上。     

In vitro plant regeneration of Vismia guianensis through organogenesis

A protocol for in vitro plant regeneration through organogenesis was established for Vismia guianensis(Hypericaceae), a species that produces an anti-cancer compound. The highest mean number of shoots per gram of callus (57.33) was obtained on Murashige and Skoog medium supplemented with 4.44 μM 6-benzyl-aminopurine, 5.70 μM indole-3-acetic acid and 12.88 μM gibberellic acid. Rooting was favoured by the addition of 10 μM indole-3-butyric acid, and by sucrose concentrations higher than 1%. This revised version was published online in June 2006 with corrections to the Cover Date.     

In vitro plant regeneration of spinach from mature seed-derived callus

Summary A system for the regeneration of spinach (Spinacia oleracea L.) from mature dry seed explants has been established. The response of two commercial spinach cultivars, ‘Grandstand’ and ‘Baker’, was examined. Callus proliferation was most prominent on MS medium supplemented with 9.3 μM of 6-furfurylaminopurine (kinetin) and 3.39 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Adventitious shoot formation was observed within 8 wk after callus was transferred onto regeneration medium. Shoot regeneration was best from callus induced on 9.3 μM kinetin and 4.56 μM 2,4-D. The regeneration medium contained 9.3 μM kinetin, 0.045 μM 2,4-D, and 2.89 μM gibberellic acid (GA₃). Shoots were rooted on hormone-free medium, and plants grown in a greenhouse showed normal phenotype. This system is beneficial in rapid propagation of spinach plants, particularly when only a limited number of seeds are available.     

A comparison of methods for callus culture and plant regeneration of RD25 rice (Oryza sativa L.) in two laboratories

While methodology is transferable from one laboratory to another, an exact transfer does not usually occur and even a nearly exact transfer of methods does not always result in repeatable data. Researchers should not expect that an effort to duplicate a published procedure will necessarily lead to identical results.In attempting to transfer rice tissue culture methods between laboratories in Fort Collins, Colorado, USA and Bangkok, Thailand, we discovered that a combination of the methods of each laboratory produced the best results in term of callus productions and plant regeneration. In the experiments reported here, the type of culture vessel used and the geographical location were also important variables.Supported by the USAID/Cooperative Agreement No DAN-4137-A-00-4053-00.     

Studies of cotyledon protoplast cultures from B napus,B. campestris and B. oleracea. II: Callus formation and plant regeneration

Cotyledons from twelve cultivars of Brassica; B. napus (Westar, Eureka, Global, Pivot and Narc 82); B. campestris: (Arlo, Sonja, Bunyip and Wonk Bok) and B. oleracea (Phenomenal Early, Sugar Loaf and Earliball) were used for protoplast isolation and culture in a comparative study of cell colony and callus formation, and plant regeneration. The formation of cell colonies and callus from protoplast cultures were significantly influenced by the light conditions of seed germination. All twelve cultivars showed callus formation from protoplast cultures derived from cotyledons of seedlings grown in dark for 3 days followed by 1 day dim light (dark/dim light-grown). Callus was obtained in all five liquid media used: modified K8P(1), modified K8P(2), modified MS, modified B and modified NN. In contrast, only six cultivars exhibited callus formation from the protoplasts isolated from cotyledons of seedlings germinated under light conditions for 7 days (light-grown) and in only three media: modified K8P(1), modified MS, modified B.Callus, derived from protoplast cultures isolated from dark/dim light-grown cotyledons and grown on K3 or MS series solid media for about 1 month, could develop shoots when further transferred onto MS series regeneration media. All five cultivars of B. napus, three of the four cultivars of B. campestris (Arlo, Sonja and Bunyip) and one of the three cultivars of B. oleracea (Sugar Loaf) exhibited shoot regeneration from protoplast cultures within 2–3 months after protoplast isolation. The frequency of shoot regeneration ranged among 1–22.5%. A high degree of reproducibility was observed in cultivars Westar, Eureka, Global, Arlo, Bunyip and Sugar Loaf. In contrast, among the six cultivars that formed callus in protoplast culture derived from light-grown cotyledons, only three cultivars from B. napus (Westar, Eureka, Global) exhibited shoot regeneration 5.5 months after protoplast isolation. Regenerated shoots from cultivars Westar, Eureka and Bunyip and Sugar Loaf, which derived from protoplasts of dark/dim light germinated seedling and were induced to root on rooting media, survived in soil and grew to produce silique and set seeds.Abbreviations 2,4-d 2,4-dichlorophenoxyacetic acid - BA benzylaminopurine - EDTA ethylenediaminetetraacetic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid - KT kinetin - GA₃ gibberellic acid - MS Murashige and Skoog medium - NAA -naphthaleneacetic acid - PAR photosynthetically active radiation     

Secondary somatic embryogenesis and plant regeneration in cassava

Somatic embryos isolated from mature seed-derived cotyledon cultures of cassava (Mannihot esculenta Crantz) underwent direct secondary somatic embryogenesis or plant development under appropriate incubation conditions. Isolated somatic embryos were subjected to a two-stage culture procedure similar to that which induced their development on cotyledon explants. This involved incubation for 24–30 days on Murashige and Skoog basal medium supplemented with 2–8 mgl^-1 2,4-dichlorophenoxyacetic acid (2,4-D) (Stage I medium) before transfer to medium supplemented with 0.01 mgl^-1 2,4-D and 0.1 mgl^-1 6-benzylamino purine (BAP) (Stage II medium). Under these conditions, secondary somatic embryos developed directly from the cotyledons and shoot-tip region of primary somatic embryos by a developmental process morphologically very similar to that occurring on zygotic cotyledon explants. Apical shoot extension and adventitious root formation occurred when somatic embryos were isolated from parental cultures and incubated on Stage II medium. Somatic embryo-derived plants growing in greenhouse conditions appeared morphologically normal when compared with non-regenerated plants.     

Induction of callus and plant regeneration in Vicoa indica

Callus cultures were initiated from the stem and leaf explants of aseptically grown Vicoa indica. A simple method is described for plant regeneration from callus and the rapid multiplication of the plants thus obtained. Callus initiation was optimum in Gamborg B5 (B5) basal medium containing either 2.0 mg l^-1 naphthaleneacetic acid (NAA) with 0.2 mg l^-1 kinetin (Kn) or 2.0 mg l^-1 6-benzylaminopurine (BAP) with 0.2 mg l^-1 NAA. The calli initiated on B5 medium were able to proliferate on both Murashige and Skoog (MS) and B5 basal medium. Shoot primordia were obtained from greenish callus on passage to B5 basal medium containing 3.0 mg l^-1 BAP and 1.0 mg l^-1 Kn. On further subculture onto B5 medium containing 0.2 mg l^-1 Kn the shoot primordia developed into plantlets.