Showing papers on "Kinetin published in 1994"
TL;DR: It is observed that an addition of 40-200 microM Kn in the culture medium of human diploid fibroblasts can both delay the onset and decrease the extent of many of the ageing characteristics that appear during serial passaging of normal cells in culture.
178 citations
TL;DR: Shoots of Eucalyptus globulus Labill cultured on shoot multiplication media containing, on alternate subcultures, 6-benzylaminopurine or 6-furfurylaminipurine (kinetin), showed better growth than cultures in which either of the cytokinins was used continuously, or both were used in an equimolar mixture.
79 citations
TL;DR: Efficient plant regeneration via somatic embryogenesis has been developed in chickpea cultivar C235 through somatic embryos with high efficiency during dark incubation and hardened plantlets produced normal, fertile plants upon transfer to soil.
Abstract: Efficient plant regeneration via somatic embryogenesis has been developed in chickpea cultivar C235. Leaf explants, on MS medium supplemented with 1.25 mg/l 2,4-D and 0.25 mg/l kinetin, yielded somatic embryos with high efficiency during dark incubation. MS medium supplemented with B5 vitamins, 0.125 mg/l IBA and 2 mg/l BAP was found suitable for embryo maturation. The well formed embryos germinated into plantlets on basal B5 medium supplemented with 0.25 mg/l BAP. Further development into healthy plantlets was obtained on basal B5 medium. Hardened plantlets produced normal, fertile plants upon transfer to soil.
73 citations
TL;DR: Plant regeneration via somatic embryogenesis was achieved in callus cultures derived from nodal explants of in vitro grown seedlings and excised mature zygotic embryos of three bamboo species on Murashige and Skoog's basal medium supplemented with 0.5 mg/l kinetin (Kn) and 3% sucrose.
Abstract: Plant regeneration via somatic embryogenesis was achieved in callus cultures derived from nodal explants of in vitro grown seedlings and excised mature zygotic embryos of three bamboo species on Murashige and Skoog's (MS) basal medium supplemented with 0.5 mg/l kinetin (Kn), 2.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), 10 mg/l adenine sulphate (Ads) and 3% (w/v) sucrose incubated in the light or in the dark. Somatic embryos germinated (95–98%) into normal plants and were transferred to soil with 95% success. In vitro flowering was induced on shoots developed from nodal explants taken from somatic embryo regenerated plants of Bambusa vulgaris, Dendrocalamus giganteus and Dendrocalamus strictus on half-strength MS basal medium supplemented with 0.25 mg/l indole-3-butyric acid (IBA), 0.5 mg/l Ads, 0.5 mg/l gibberellic acid (GA3) and 3% sucrose.
69 citations
TL;DR: Regenerants from TIBA plus BA or kinetin media were successfully established in the soil (86% survival rate), where they flowered and showed normal meiotic behaviour with 100% pollen viability and plantlets obtained were normal diploids while those from BA or Kinetin alone revealed distinct chromosomal aberrations in their root tip squashes.
Abstract: The effect of various concentrations of benzyladenine (BA 4.4–177.5 μM) or kinetin (4.7–185.9 μM) on shoot proliferation from shoot-tip explants was investigated in C. praetermissum Heiser & Smith and C. annuum L. Maximum number of shoots were obtained on Murashige & Skoog's medium with 66.6 μM BA or 92.9 μM kinetin in C. praetermissum, and 88.8 μM BA or 116.2 μM kinetin in C. annuum after 4 weeks of culture. Combining 1 μM 2, 3, 5-triiodobenzoic acid (TIBA) with low levels of BA or kinetin significantly increased shoot number as compared to using either cytokinin alone. Rooting of regenerated shoots was achieved on MS medium containing 5.7 μM indoleacetic acid. Best rooting (80–100%) was observed in shoots from TIBA plus BA or kinetin media while only 40–50% of shoots from the BA or kinetin treatments were rootable. Plantlets obtained from TIBA plus BA or kinetin were normal diploids while those from BA or kinetin alone revealed distinct chromosomal aberrations in their root tip squashes. Regenerants from TIBA plus BA or kinetin media were successfully established in the soil (86% survival rate), where they flowered and showed normal meiotic behaviour with 100% pollen viability.
67 citations
TL;DR: During this process, ABA rapidly induces elevated levels of mRNA transcripts encoding a novel basic peroxidase, and in the presence of the cytokinin kinetin the maintained increase is attenuated and Kinetin not only totally inhibits the induction of turion formation but also alleviates ABA-induced growth inhibition.
Abstract: The growth regulator abscisic acid (ABA) can be used to induce dormant bud structures (turions) in the duckweed Spirodela polyrrhiza L. In this paper we show that during this process, ABA rapidly induces elevated levels of mRNA transcripts encoding a novel basic peroxidase. In addition, we show that in the presence of the cytokinin kinetin the maintained increase is attenuated. Kinetin not only totally inhibits the induction of turions by ABA but also alleviates ABA-induced growth inhibition. This antagonism of an ABA-induced gene by a cytokinin correlates with an easily observable antagonistic effect of these two hormones on plant morphogenesis. These data contribute to a growing body of evidence linking growth regulators with changes in peroxidase gene expression and to the concept of pairs of hormones playing antagonistic roles during plant development. Finally, we discuss the possible functions that peroxidases could have during ABA-induced turion formation and growth inhibition.
61 citations
TL;DR: Clonal micropropagation was established by shoot tip culture and was maintained on Murashige and Skoog medium supplemented with kinetin and gibberellic acid A 3 and callus that was induced and maintained on supplements of 2,4-dichlorophenoxyacetic acid and 6-benzylaminoputine in the absence of light.
Abstract: Callus tissue from petioles of Salvia miltiorrhiza was obtained on Murashige and Skoog medium supplemented with indole-3-butyric acid and 6-benzylaminopurine. When the calli were subcultured, adventitious shoots formed. These shoots developed into normal plantlets with roots when transferred to hormone-free Murashige and Skoog medium. Clonal micropropagation was established by shoot tip culture and was maintained on Murashige and Skoog medium supplemented with kinetin and gibberellic acid A 3 . Callus that was induced and maintained on supplements of 2,4-dichlorophenoxyacetic acid and 6-benzylaminoputine in the absence of light produced rosmarnic acid (1.24% dry wt) and lithospermic acid B (0.10% dry wt)
58 citations
TL;DR: Stem cuttings of potato plants were cultured in vitro on MS medium with sucrose either without or with addition of indole-3-acetic acid (IAA) or kinetin (K) under red light (R) or blue light (B).
Abstract: Stem cuttings of potato plants (Solanum tuberosum L., cv. Miranda) were cultured in vitro on MS medium with sucrose either without or with addition of indole-3-acetic acid (IAA) or kinetin (K) under red light (R) or blue light (B). Plants on medium without hormones under R were thin, long, with very small leaves, and produced no or only a few microtubers (after longer-lasting cultivations). In B, plants remained short, thick, with large, wellde-veloped leaves and produced a significant amount of microtubers. Darkening of both roots and shoots strongly promoted tuber formation; the tubers were formed on the darkened part of the plant. IAA had no pronounced effect on plant development in B except for slight lengthening of the stem, and, in longer cultivations, slightly enhanced tuber formation as well. In R, IAA brought about several significant effects: stem reduction and induction of tuber formation being the most significant. Kinetin in R increased tuber formation slightly. In B, kinetin not only strongly stimulated tuber formation, but also increased the total fresh weight and root (+ stolons)/shoot ratio. Results are discussed with regard to the possible role of auxins and/or cytokinins in mediating the morphogenetic effects of light.
58 citations
TL;DR: The results suggested that it has became feasible to find the most effective conditions for cell growth and anthocyanin production by optimizations of the nitrogen concentration and the ratio of NH4+ to NO3- in the medium.
Abstract: High anthocyanin-producing cell lines, which were grown in a dark or in a light-dark regime, were selected from callus cultures initiated from stem and leaf tissues of Aralia cordata Thunb. by small-cell-aggregate selection. To verify the optimum culture conditions for anthocyanin production, cells were tested by changing the various basal media, sucrose concentration and nitrogen source and concentration. Good growth was obtained in the dark on Linsmaier-Skoog's basal medium containing 1.0 mg l-1 2,4-d and 0.1 mg l-1 kinetin, 2% (w/v) sucrose and full strength of nitrogen concentration. However, the highest anthocyanin yield (10.3% dry wt) was obtained in the dark on B5 medium containing 1.0 mg l-1 2,4-d and 0.1 mg l-1 kinetin. Our results suggested that it has became feasible to find the most effective conditions for cell growth and anthocyanin production by optimizations of the nitrogen concentration and the ratio of NH4
+ to NO3
- in the medium.
52 citations
TL;DR: The results revealed that for the induction of embryogenic callus and somatic embryogenesis of Cayratia japonica, both cytokinin and auxin are required in the medium and the cytokinIn activity of TDZ is much stronger than that of kinetin even when the concentration of TDz used was only 4% of Kinetin.
Abstract: Unpollinated ovary explants of Cayratia japonica (Thump.) Gagnep, were cultured on the revised Murashige & Skoog's medium supplemented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-d) alone, or in combination with 0.009 μM thidiazuron (TDZ) or 0.23 μM kinetin for induction of embryogenic callus. The best results were obtained on medium containing 2.3 – 4.6 μM 2,4-d and TDZ. When the calluses were subcultured on the basal medium (BM), somatic embryogenesis took place spontaneously at surfaces of the calluses, but only about 5% of the somatic embryos could develop to cotyledonary stage and most of the rest remained at the globular stage of development. If the calluses were transferred onto medium containing TDZ or TDZ combined with 0.27 μM α-napthaleneacetic acid, the number of cotyledonary somatic embryos increased up to 25%. When the somatic embryos of different stages were transferred onto fresh BM, only the cotyledonary embryos could convert into the plantlets. The results revealed that for the induction of embryogenic callus and somatic embryogenesis of Cayratia japonica, both cytokinin and auxin are required in the medium and the cytokinin activity of TDZ is much stronger than that of kinetin even when the concentration of TDZ used was only 4% of kinetin.
47 citations
TL;DR: The effect of 6-furfurylaminopurine (kinetin) on the HR of potato tubers challenged with Phytophthora infestans was investigated and a hypothetical model linking senescence and HR physiology via oxidative damage is briefly presented.
TL;DR: Although, high frequency shoot regeneration was obtained from all petal explants harvested from various developmental stages of buds, a significant decrease in regeneration capacity was observed in the explants obtained from fully-opened flowers.
Abstract: Adventitious shoot regeneration was compared among leaf, stem and petal explants of carnation (Dianthus caryophyllus L.) cv. Scania on MS medium containing different concentrations of 6-benzyladenine (BA) and α-naphthaleneacetic acid (NAA). High frequency regeneration was obtained only from petal explants on the media containing 5 to 10 μM BA with or without 5 μM NAA. Among the cytokinins tested, N-2-chloro-4-pyridyl-N′-phenylurea and N-1,2,3-thiadiazol-5-yl-N′-N′-phenylurea were more effective than BA, kinetin, N6-2-isopentenyl adenine and zeatin on regeneration from petal explants. Although, high frequency shoot regeneration was obtained from all petal explants harvested from various developmental stages of buds, a significant decrease in regeneration capacity was observed in the explants obtained from fully-opened flowers. High frequency shoot regeneration was also obtained from the petal explants of cvs. Coral. Lena, Nora and White Sim, and an interspecific cultivar Eolo using the method developed in this study.
TL;DR: The interaction of auxin (NAA), cytokinins (BA, kinetin, 2iP and zeatin) and culture environment (light and temperature) on bulblet production from bulbscale explants of Lilium japonicum Thunb.
Abstract: SummaryThe interaction of auxin (NAA), cytokinins (BA, kinetin, 2iP and zeatin) and culture environment (light and temperature) on bulblet production from bulbscale explants of Lilium japonicum Thunb. were investigated. A combination of NAA and 2iP, in general, gave a better response than combinations involving other cytokinins. An incubation temperature of 20°C and continuous illumination were better than growing at 25°C in the dark. Regenerated bulblets predominantly originated from the basal end of explants in the control medium and this polarity was reversed by supplementing the medium with NAA + BA or NAA + 2iP. The importance of an illuminated environment for leaf induc-tion in regenerated bulblets is discussed.
TL;DR: In vitro methods for rapid propagation, and morphogenetic potential of the rare and endangered bulb species Leucojum aestivum L., Amaryllidaceae, and Lilium rhodopaeum Delip.
Abstract: The present work deals with the in vitro methods for rapid propagation, and morphogenetic potential of the rare and endangered bulb species Leucojum aestivum L., Amaryllidaceae, and Lilium rhodopaeum Delip., Liliaceae. The morphogenetic potential of different plant organs (bulb, stem, leaves and ovaries) was studied. Leaves of Leucojum aestivum L. and basal parts of the bulb in Lilium rhodopaeum Delip. possess the highest regeneration activity. Murashige and Skoog (MS) medium + 1 mg/l 6-benzylaminopurine (BAP) + 1 mg/l kinetin and Linsmaier and Skoog (LS) medium + 0.5 mg/l 1-naphthaleneacetic acid (NAA) + 0.1 mg/l kinetin were favourable for direct organogenisis from these explants. A stimulating effect of alow gamma-irradiation dose (5 Gy) upon the quantity and growth intensity of the bulbs formed by the explants in in vitro conditions is observed.
TL;DR: Upon exposure of the leaves to light, the dark-accumulated Pchlide was efficiently phototransformed to chorophyllide (Chlide), even on the 7th d of dark incubation, demonstrating that the activity of PchLide reductase, one of the late enzymes of the Chl biosynthetic pathway, is not substantially affected during senescence.
Abstract: The chlorophyll (Chl) biosynthetic reactions were monitored during senescence of dark-incubated excised barley (Hordeum vulgare L. cv IB 65) leaves floated in double-distilled water or kinetin solution. Kinetin abolished the degradation of Chl but failed to check the net degradation of protochlorophyllide (Pchlide), suggesting that different sets of enzymes, i.e. kinetin sensitive and insensitive, are responsible for the degradation of Chl and Pchlide, respectively. Upon exposure of the leaves to light, the dark-accumulated Pchlide was efficiently phototransformed to chorophyllide (Chlide), even on the 7th d of dark incubation, demonstrating that the activity of Pchlide reductase, one of the late enzymes of the Chl biosynthetic pathway, is not substantially affected during senescence. The senescing leaves continued to synthesize Pchlide and Chlide until the 7th d, although at a reduced rate (20% of the 1st d). The decline of the rate of synthesis of Pchlide and Chlide is due to the loss of activity of two early enzymes of the Chl biosynthetic pathway, i.e. 5-aminolevulinic acid dehydratase and porphobilinogen deaminase. Kinetin substantially checked the loss of activity of these two enzymes.
TL;DR: Multiple shoots were obtained from shoot tips derived from mature plants (5 to 6 years old) of Citrus reticulata Blanco CV.f.
Abstract: Multiple shoots were obtained from shoot tips (2 to 3 mm) derived from mature plants (5 to 6 years old) of Citrus reticulata Blanco CV. Khasi mandarin and C. limon Burm.f. CV. Assam lemon when cultured on Murashige and Skoog (MS) medium, supplemented with (mg·liter -1 ) 1.0 BAP, 0.5 kinetin, and 0.5 NAA. Root induction was observed when 7-week-old single shoots (≈ 2 cm long) of both Citrus species were cultured on MS medium supplemented with (mg·liter -1 ) 0.25 BAP, 0.5 NAA, and 0.5 IBA. These plantlets were successfully established in the soil. Chemical names used: naphthalene acetic acid (NAA), indole 3-butyric acid (IBA), and benzylamino purine (BAP). plants from the orchard of the Assam Agricul- tural Univ., Jorhat. The expanded leaves were removed and washed thoroughly with a 1% solution of the detergent Teepol (Sigma, St. Louis) and then washed thoroughly with dis- tilled water. Explants were surface-sterilized with 2% (w/v) calcium hypochlorite solution
TL;DR: The isozymes of esterase, peroxidase, glutamate oxaloacetate transaminase and acid phosphatase investigated in this study were found appropriate to distinguish compact embryogenic from friable non-embryogenic callus in sweet potato.
Abstract: The potential of somatic embryogenesis was evaluated for 10 cultivars of sweet potato through extensive embryogenic response and isozyme analysis. Embryogenic callus was induced by incubating lateral buds on Murashige and Skoog medium containing 10 μM 2,4-dichlorophenoxyacetic acid for 6–8 weeks. The frequency of embryogenic response was low, and varied with genotypes, ranging from 0 to 17%. Embryo to plantlet formation could be enhanced by the use of the combination of 2,4-dichlorophenoxyacetic acid with kinetin, both used at 0.01 μM. Embryogenic callus with its potential of plantlet formation has constantly been maintained for over two years. However, after several subcultures, 0.5 to 12% of embryogenic callus reverted irreversibly into friable fast-growing non-embryogenic callus whose ability to regenerate shoots was then definitively lost. The isozymes of esterase, peroxidase, glutamate oxaloacetate transaminase and acid phosphatase investigated in this study were found appropriate to distinguish compact embryogenic from friable non-embryogenic callus in sweet potato. In fact, the callus reversion was associated with a loss of bands or a decline in isozyme activity. On the contrary, very small changes in isozyme activity or no specific changes at all were observed during the differentiation of embryogenic callus into globular embryos.
TL;DR: Flowering was induced in 7-month-old × Doriella Tiny (Doritis pulcherrima × Kingiella philippinensis) explants in an vitro system and BA was required for the formation of floral buds on explants under certain nutritional conditions, including the appropriate content of sucrose and nitrogen in the culture media.
TL;DR: Somatic embryogenesis and subsequent plant regeneration of Euonymus europaeus L (European Spindle Tree) were obtained from square pieces of mature zygotic embryos with an intervening callus phase and development of somatic embryos into plantlets was achieved on a medium devoid of growth regulators.
Abstract: Somatic embryogenesis and subsequent plant regeneration of Euonymus europaeus L (European Spindle Tree) were obtained from square pieces of mature zygotic embryos with an intervening callus phase Callus and somatic embryos were induced using a Murashige and Skoog's semi-solid basal medium supplemented with several combinations of auxins and cytokinins The greatest number of somatic embryos was obtained with a continuous exposure to 228 μM indoleacetic acid and 0046 μM kinetin The frequency of somatic embryogenesis from zygotic embryos depends on the cold conservation time of seeds The embryos frequently germinated on the same medium Further development of somatic embryos into plantlets was achieved on a medium devoid of growth regulators
TL;DR: Somatic embryos could be induced from the cotyledons of zygotic embryos from immature fruits of Feijoa sellowiana Berg in the presence of a wide range of concentrations of fructose, glucose, maltose, and sucrose in order to improve somatic embryogenesis by acting both as carbon source and as osmotic regulator.
Abstract: Somatic embryos could be induced from the cotyledons of zygotic embryos from immature fruits ofFeijoa sellowiana Berg (Feijoa) in the presence of a wide range of concentrations of fructose, glucose, maltose, and sucrose. Mannitol or sorbitol alone were ineffective. The highest frequencies of induction (99%) and the greatest number of somatic embryos per explant (134) were obtained with 0.4M fructose and 0.3M sucrose, respectively. This sucrose concentration also showed greater induction capacity than equimolar combinations of its monosaccharide constituents combined. Somatic embryo development was arrested at the globular stage at concentrations higher than 0.5M of all the sugars tested. When transferred to solid germination medium containing 2.0 mg/liter (5.77µM) gibberellic acid, 0.5 mg/liter (2.32µM) kinetin, and 0.029M sucrose, somatic embryos formed under 0.3 or 0.4M sucrose had better germination capacity than those induced under lower (0.1 and 0.2M) concentrations, as assessed by the frequency of explants presenting germinated embryos and by the number of plants obtained from those explants. On liquid media of similar composition somatic embryos did not germinate. Our data suggest that high (0.3 to 0.4M) carbohydrate levels improve somatic embryogenesis by acting both as carbon source and as osmotic regulator.
Journal Article•
TL;DR: In the culture system, the type of cytokinin was the key to control the morphogenic pathways, and one of the most active urea cytokinins, N-(2- chloro- 4- pyridyl)-N' -phenylurea (4PUCl), tended to induce adventitious shoots.
Abstract: There are two morphogenic pathvways in plant regeneration. These are adventitious shoot and root formation (organogenesis) and somatic embryo formation (embryogenesis). To establish a rice (Oryza sativa L.) culture system, in which highly-frequency of either organogenesis or embryogenesis were achieved, effective regeneration media were investigated. We tested N6 medium containing 20 g·l-1 sucrose, 35 or 50 g·l-1 sorbitol, 3 g·l-1 casein hydrolysate, lO mM L-proline, 10 g'l-1 agarose and different levels of abscisic acid (ABA), auxin, and cytokinin for regeneration. In our culture system, the type of cytokinin was the key to control the morphogenic pathways. One of the most active urea cytokinins, N-(2- chloro- 4- pyridyl)-N' -phenylurea (4PUCl), tended to induce adventitious shoots. A purine cytokinin, kinetin, in low concentration tended to induce somatic embrvos.
TL;DR: Seedlings of silktree were grown in vitro on MS-media containing B5 vitamins, 3% sucrose, 0.25% phytagel and various concentrations (0.1–10 μM) of thidiazuron (TDZ), and addition of TDZ to the culture medium greatly reduced shoot and root elongation but did not influence shoot production from the cotyledonary node or apex.
Abstract: Seedlings of silktree (Albizzia julibrissin Durrazz.) were grown in vitro on MS-media containing B5 vitamins, 3% sucrose, 0.25% phytagel and various concentrations (0.1–10 μM) of thidiazuron (TDZ). Addition of TDZ to the culture medium greatly reduced shoot and root elongation but did not influence shoot production from the cotyledonary node or apex. Within 8–10 days the seedling roots split open, formed large masses of callus, and developed green patches which eventually grew into normal shoots while still within the culture medium containing TDZ at 0.1–1.0 μM. Such callus and shoot formation did not occur in control cultures lacking TDZ. At higher TDZ concentrations (2.5–10 μM), the green patches formed in the callus did not further develop into shoots. Addition of other cytokinins (kinetin, benzylaminopurine, zeatin) to the culture medium also induced some shoot formation from the roots, but higher concentrations than TDZ were required to induce regeneration. Isopentenyladenine failed to induced shoot formation. Following excision and transfer to MS media with or without 4.9 μM IBA, the shoots induced by kinetin or benzylaminopurine rooted 4–7 days earlier than those induced by TDZ, but all excised shoots developed into normal rooted plantlets within 3 weeks.
TL;DR: A micropropagation system was developed for Acacia mearnsii De Wild, the principal source of the world’s tanbark and an excellent firewood, which promoted multiple shoot formation and rooting of the shoot tip explants.
Abstract: A micropropagation system was developed forAcacia mearnsii De Wild., which is the principal source of the world’s tanbark and an excellent firewood. Shoot tips 5-mm long from 3-wk-old seedlings germinated in vitro served as explants. The seeds were germinated on hormone-free MS medium and the shoot tips were cultured on three-fourth-strength MS medium supplemented with combinations of auxins [indole-3-butyric acid (IBA) andα-naphthaleneacetic acid (NAA)] and cytokinins [kinetin and benzylaminopurine (BAP)]. Cultures were maintained at 25° ± 5° C and exposed to 12-h photoperiods of cool-white fluorescent light (70 µEm−2·s−1). Multiple shoot formation was promoted by BAP at 2 mg · liter−1 (8.87µM) and higher combined with or without 0.01 mg · liter−1 (0.049µM) IBA. Cytokinins at concentrations of less than 1 mg · liter−1 combined with 0.01 to 0.1 mg · liter−1 auxin inhibited multiple shoot formation and promoted rooting of the shoot tip explants. Shoot multiplication cultures were maintained by transferring segments of multiple-shoot clusters onto a medium containing 2 mg · liter−1 BAP and 0.01 mg · liter−1 IBA. Although higher levels of BAP promoted more multiple shoot formation, this BAP level allowed shoot elongation as well as multiplication. In-vitro-produced shoots were induced to root on a range of NAA concentrations (0.0 to 0.8 mg · liter−1[4.3µM]) supplemented to half- or full-strength MS medium. The highest frequency of root proliferation was on half-strength MS medium supplemented with 0.6 mg · liter−1 (3.22µM) NAA. Plantlets survived in potting soil and exhibited normal growth under greenhouse conditions.
TL;DR: The development of microspore derived proembryos was obtained in MS medium supplemented with 2.2 μM N6-benzyladenine and reached the highest level when the microspores were cultured in MS6 inducing medium, and the development ofmicrospore-derived embryos ceased at the maturation stage.
Abstract: Three methods of microspore culture were tested for the induction of microspore embryogenesis in Camellia japonica L. cv. Elegans. Culture was performed on 17 different media consisting of Murashige and Skoog (MS) and N6 basal media with different combinations of carbon, growth regulators, serine and glutamine. Microspore suspensions plated over solid MS medium containing 4.5 μM 2,4-dichlorophenoxyacetic acid and 0.5 μM kinetin, with sucrose (MS6) or glucose (MS9) were seen as the best culture conditions for induction of embryogenesis. The development of microspore derived proembryos was obtained in MS medium supplemented with 2.2 μM N6-benzyladenine (MS10) and reached the highest level when the microspores were cultured in MS6 inducing medium. The development of microspore-derived embryos ceased at the maturation stage.
TL;DR: In all experimental situations in which tuber formation was stimulated, IAA level in roots and stolons rose significantly, stressing the importance of an IAA gradient for tuber formation.
Abstract: The levels of endogenous IAA and cytokinins (zeatin, zeatin riboside, isopentenyladenine, and isopentenyladenosine) were determined in potato plants cultured in vitro under red light (R) and blue light (B) on medium with or without hormones. On medium without hormones in B, plants contained much higher cytokinin levels, particularly in leaves and roots, and also slightly elevated IAA levels. Kinetin in the medium in B changed the distribution of cytokinins and significantly increased IAA level in roots. In R, the presence of kinetin led to an increased cytokinin level in the whole plant, while the IAA level was slightly lower. IAA in the medium in B decreased cytokinin level in all plant parts, while the IAA level did not change significantly. In R, the presence of IAA in the medium led to a moderate increase of CK level and to a significant increase in IAA level, especially in roots. Uptake of 1-14C-IAA and of 3H-zeatin was generally higher in B than in R. Higher percentage of IAA taken up in B was converted to conjugates in the roots. Metabolism of 3H-zeatin was similar in R and B with only slight differences in metabolite amounts. Thus, in all experimental situations in which tuber formation was stimulated, IAA level in roots and stolons rose significantly, stressing the importance of an IAA gradient for tuber formation.
TL;DR: Three Eucalyptus grandis x E. urophylla clones selected for their rapid growth and desirable pulping qualities were successfully multiplied in culture using half strength Murashige & Skoog (1962) medium and clonal differences were observed in the rooting potential, as well as in the establishment success of the plantlets.
TL;DR: C Cotyledons from seedlings of various ages of Aegle marmelos were cultured on Murashige and Skoog medium supplemented with different combinations of phytohormones and the proximal part of the cotyledon had the highest regeneration potential.
TL;DR: Because of the isozyme variations, which developed in culture medium and were transferred to the regenerated plants, the IDH, ACP, PER, and EST enzyme systems can be considered to be good markers for investigating possible genetic variations in plant populations of C. peruvianus obtained in vitro from callus culture.
Abstract: Electrophoretic patterns for isocitrate dehydrogenase (IDH; EC 1.1.1.42), acid phosphatase (ACP; EC 3.1.3.2), peroxidase (PER; EC 1.11.1.7), and esterase (EST; EC 3.1.1.1) isozymes were determined inCereus peruvianus tissues and used as markers of genetic uniformity of calli and of the plants regenerated from callus cultures. One IDH, six ACP, six PER, and six EST isozymes were induced in cultured callus tissues in medium containing three 2,4-dichlorophenoxyacetic acid and kinetin combinations. Four ACP, two PER, and three EST isozymes were still present in all regenerated plantsin vitro and therefore can be used as markers of theC. peruvianus plants regenerated from callus tissues. The differential patterns of ACP and IDH isozymes and the similar zymograms for PER and EST isozymes presented by callus tissues were used in a comparison of callus tissues cultured for 2 years. The comparative analysis of zymograms within each enzyme system indicated a mean heterogeneity coefficient of 0.33 forC. peruvianus calli cultured for 2 years. Because of the isozyme variations, which developed in culture medium and were transferred to the regenerated plants, the IDH, ACP, PER, and EST enzyme systems can be considered to be good markers for investigating possible genetic variations in plant populations ofC. peruvianus obtainedin vitro from callus culture.
TL;DR: A system for high frequency plant regeneration from cell suspension cultures in Catharanthus roseus is described and yellowish compact colonies proliferated from the cells and more than 80% of them gave rise to somatic embryos.
Abstract: A system for high frequency plant regeneration from cell suspension cultures in Catharanthus roseus is described. Calli were obtained from anthers cultured on Murashige and Skoog's medium supplemented with 1 mgl-1α-naphthaleneacetic acid and 0.1 mgl-1 kinetin. After the second subculture on solid medium, embryogenic callus was identified and transferred to liquid medium to initiate suspension cultures. Cells dispersed finely in the medium were subcultured at 14-day intervals. Upon plating onto the basal medium, yellowish compact colonies proliferated from the cells and more than 80% of them gave rise to somatic embryos. Subsequently, plantlets developed from the embryos. Both the plantlets and the source plants showed the normal somatic chromosome number of 2n=2x=16.