Showing papers in "Plant Cell Tissue and Organ Culture in 1998"
TL;DR: A new protocol was established for sugarcane cv.
Abstract: A new protocol was established for sugarcane cv C-1051-73 shoot formation in a temporary immersion system The two-step protocol involves shoot formation in 50 ml of culture medium per explant and 10 mg l-1 paclobutrazol for 30 days followed by shoot elongation by exposure to 10 mg l-1 gibberellic acid for 15 days The multiplication rate was doubled in comparison with the conventional micropropagation protocol (Jimenez et al, 1995) and the cost has been reduced by 46% Three additional sugarcane varieties have been micropropagated according to this new protocol and results are comparable Temporary immersion-derived plants have also been compared with conventionally propagated plants in sugarcane fields for more than 9 months and their agricultural indicators of performance are similar
179 citations
TL;DR: In this paper, the effects of genotypes with callus induction and regeneration media combinations on green plantlet regeneration response were studied for three indica rice (Oryza sativa L.) cultivars, IR-72 and IR-54, and fifteen media combinations involving MS, N6, R2, SK1 and some modifications were tested.
Abstract: Interactive effects of genotypes with callus induction and regeneration media combinations on green plantlet regeneration response were studied for three indica rice (Oryza sativa L.) cultivars, IR-72, IR-54 and Karnal Local. Isolated mature-embryos were used to derive scutellar callus and fifteen media combinations involving MS, N6, R2, SK1 and some modifications were tested. Regeneration percentage as well as the shoot-bud induction frequency were influenced by genotype, callus induction medium, regeneration medium, interaction between genotype and the two media (callus induction and regeneration) as well the interaction between the callus induction medium and regeneration medium. Basal media combination of SK1m (callusing) and MS (regeneration) was found to be the best for cv. Karnal Local in which regeneration frequency of 88% and shoot-bud induction of 233% was observed. In IR-72, the highest regeneration frequency of 47.5% and shoot-bud induction frequency of 77% was obtained on MS-MS combination. In IR-54, highest regeneration frequency (25%) was recorded on MMS(N)-MMS(N) combination, whereas, highest frequency of shoot-bud induction (50%) was observed on MMS(S)-MS combination. Although genotype and the composition of the callus induction basal medium were the major determinants of regeneration response, an overall analysis of variation also revealed a significant interaction between the media used for de-differentiation (callusing) and re-differentiation (plantlet regeneration).
126 citations
TL;DR: The results obtained in this study suggest that rooting parameters are the most useful traits for rapid evaluation and screening of tomato species and segregating populations through in vitro shoot apex culture.
Abstract: The possibility of using in vitro shoot apex culture to evaluate salt tolerance of cultivated (Lycopersicon esculentum Mill.) and wild (Lycopersicon pennellii (Correll) D'Arcy) tomato species was determined and related to the response obtained by callus culture. Both apices and calluses were grown on media supplemented with 0, 35, 70, 105, 140, 175 and 210 mM NaCl, and growth and physiological traits were determined. Most apices of L. esculentum did not develop roots from low NaCl levels, whereas the apices of L. pennellii were able to develop roots at the different salt levels. This different degree of salt tolerance between L. esculentum and L. pennellii was not, however, clearly shown on the basis of the shoot growth of the plantlets. The callus response was similar to that shown by the rooting parameters, as callus growth in response to increased salinity was much greater in L. pennellii than in the tomato cultivar. K+decreased more and proline accumulated less with salinity in shoots of L. esculentum compared to L. pennellii, whereas the opposite response was obtained in calluses. The results obtained in this study suggest that rooting parameters are the most useful traits for rapid evaluation and screening of tomato species and segregating populations through in vitro shoot apex culture.
109 citations
TL;DR: According to microscopical observations, the cells that retained their viability and regrowth ability after cryopreservation were the embryonal head cells, as well as some elliptic suspensor cells close to the embryo head cell area.
Abstract: The aim of the study was to develop an effective cryopreservation method for Scots pine (Pinus sylvestris L.) embryogenic cultures. Altogether nine cell lines derived from three mother trees were cryopreserved after cold hardening using dimethylsulfoxide or two different mixtures of polyethyleneglycol 6000, glucose and dimethylsulfoxide as cryoprotectants. Seventy-eight percent of the cell lines remained viable after cryostorage, the best cryoprotectant treatment being 10% polyethyleneglycol 6000, 10% glucose, and 10% dimethylsulfoxide in water. This treatment resulted in significantly better regrowth of the embryogenic cultures than with the other cryoprotectants or with the controls. According to microscopical observations, the cells that retained their viability and regrowth ability after cryopreservation were the embryonal head cells, as well as some elliptic suspensor cells close to the embryonal head cell area. When proliferation growth of the frozen cultures had started, their morphological appearance was the same as the non-frozen cultures. In addition, the RAPD assays suggested that the cryostorage treatment used here preserved the genetic fidelity of the Scots pine embryogenic cultures.
97 citations
TL;DR: Thidiazuron either alone or in combination with IAA induced high frequency shoot regeneration from primary leaf segments of three pigeonpea cultivars and Histological studies confirmed the mode of regeneration as shoot organogenesis.
Abstract: Thidiazuron either alone or in combination with IAA induced high frequency shoot regeneration from primary leaf segments of three pigeonpea cultivars Transfer of the cultures to medium with reduced concentration of thidiazuron resulted in further development of the shoots The regenerated shoots were subsequently transferred to medium supplemented with BA, IAA and gibberellic acid where 5-10% of the shoots elongated further Rooting of shoots could be obtained on half strength MS medium supplemented with NAA Histological studies confirmed the mode of regeneration as shoot organogenesis
87 citations
TL;DR: The growth regulator balance and culture conditions on the morphogenetic response of leaf disks from greenhouse grown plants of the strawberry cultivar Chandler, have been studied and the transgenic nature of several shoots was confirmed by the GUS assay and PCR analysis.
Abstract: The effects of growth regulator balance and culture conditions on the morphogenetic response of leaf disks from greenhouse grown plants of the strawberry cultivar Chandler, have been studied. Best results were obtained in the presence of 2.46 μM IBA and 8.88 μM BA, where 47% of the cultures regenerated after 16 weeks with 2.9 shoot colonies per regenerating leaf disk. Optimum incubation conditions included two weeks in the dark with subsequent transfer to light (40 μmol m-2 s-1, 16 h). The regeneration protocol was also valuable when leaf disks from in vitro grown plants were used as explants. Transformation was attempted using Agrobacterium tumefaciens carrying the plasmid pBI121. Leaf disks from in vitro cultures proliferating in the presence of 2.21 μM kinetin were best explants for transformation. A 4.22% of inoculated explants showed kanamycin resistance after 16 weeks in a medium containing 25 mg l-1 of this antibiotic. The transgenic nature of several shoots was also confirmed by the GUS assay and PCR analysis.
84 citations
TL;DR: It was demonstrated that the production of solasodine was shown to be growth-dependent in hairy root cultures but not in callus cultures, and the individual and combined effects of medium components on the growth index and theProduction of sol asodine were analyzed using factorial analysis of variance.
Abstract: The production of the steroidal alkaloid solasodine, an alternative to diosgenin as a precursor for the commercial production of steroid drugs, was studied in hairy root, callus, and cell suspension cultures of Solanum aviculare Forst through manipulation of culture medium The individual and combined effects of medium components on the growth index and the production of solasodine were analyzed using factorial analysis of variance Solasodine content was optimized to 62 mg g−1in the hairy root, 14 mg g−1callus, and 07 mg g−1in cell suspension cultures (dry weight) An improved isocratic reversed phase high performance liquid chromatographic method provided selective determination of the solasodine content of these samples Analysis of growth and solasodine content of hairy root cultures and callus cultures demonstrated that the production of solasodine was shown to be growth-dependent in hairy root cultures but not in callus cultures
81 citations
TL;DR: Results showed that, in grapevine cell suspensions, dimethyl-β-cyclodextrins themselves do not need the co-cultivation with bacteria to act as elicitors of the cells producing trans-resveratrol, a phytoalexin of grapevines.
Abstract: Gamay cell cultures were treated with dimethyl-β-cyclodextrins in order to ascertain their effect on resveratrol metabolism before and after inoculation with Xylophilus ampelinus. The results showed that, in grapevine cell suspensions, dimethyl-β-cyclodextrins themselves do not need the co-cultivation with bacteria to act as elicitors of the cells producing trans-resveratrol, a phytoalexin of grapevines. Dimethyl-β-cyclodextrins protected cell suspensions against bacteria by maintaining a high level of peroxidase activity.
79 citations
TL;DR: To select genotypes – especially Japanese ones – with a high regeneration capability, 107 wheat genotypes were screened for callus induction and regeneration capability from anther and immature embryo cultures and very few genotypes produced albino plants.
Abstract: Plant regeneration via tissue culture varies with the genotype and is an important factor in establishing cell selection and genetic transformation systems. To select genotypes – especially Japanese ones – with a high regeneration capability, we screened 107 wheat genotypes (78 domestic, 29 foreign) for callus induction and regeneration capability from anther and immature embryo cultures. For anther culture, 83 of 107 genotypes tested induced calli and 45 regenerated plants. Only 9 genotypes, however, produced green plants, 25 produced only albino plants, and 11 produced both green and albino plants. Glennson 81 was the highest in callus induction, followed by Orofen, Danchi–komugi and Chris. The genotypes with a relatively high regeneration capability were Framala 80 at 24% and Glennson 81 at 19%, these two genotypes produced only green plants. For immature embryo culture, 97 genotypes showed a 90% callus induction rate and 74 genotypes regenerated plants. Very few genotypes produced albino plants. The genotypes with a high regeneration capability were Genaro 81 at 90%, Chinese Spring at 80%, and Norin 75 at 75%.
78 citations
TL;DR: Genotype dependency may exist since in ‘Stout’ heat pretreatment did not increase embryo production, but the quality of embryos was improved in the presence of 10% maltose, and sub-optimal carbohydrate levels did not enhance embryo induction in oats.
Abstract: The effect of stress pretreatments on embryo induction in anther cultures of selected genotypes of Avena sativa and A. sterilis was tested. A heat pretreatment of isolated anthers at +32°C for 5 days was best for the A. sativa line WW 18019 and for A. sterilis line CAV 2648. Genotype dependency may exist since in ‘Stout’ heat pretreatment did not increase embryo production. For A. sterilis 13 green and three albino regenerants were produced, of which five plants (haploids) survived transfer to the greenhouse. For A. sativa, 30 various differentiation media/treatment combinations were used in an attempt to regenerate plants from embryos, with no success. Seven day cold treatment of cut tillers increased slightly the response level in ‘Stout’ and was routinely used in subsequent experiments. Maltose proved to be better then sucrose as a carbon source for the genotypes tested. Fourteen percent maltose promoted the highest induction in A. sterilis, but the quality of embryos was improved in the presence of 10% maltose for both species. Sub-optimal carbohydrate levels did not enhance embryo induction in oats.
71 citations
TL;DR: Anderson Rhododendron was as effective as Murashige and Skoog overall in promoting both microtuber induction and growth and media formulations Lloyd and MacCown and White supported the lowest frequencies of microTuber induction when kinetin was present at 2.5 μM.
Abstract: The individual effects of sucrose, plant growth regulators and basal salt media formulations were investigated on microtuber induction and development in shoot cultures of the steroid yam Dioscorea composita. Sucrose at 8% (w/v) was the single most significant medium constituent for microtuber induction. Of the four cytokinins tested, 6-benzyladenine at 1.25 and 2.5 μM showed strong inhibitory effects on microtuber induction. By contrast, the auxins α-naphthaleneacetic acid and indole-3-butyric acid at 5.0 μM showed striking promotive effects on microtuber induction and growth. In the presence of either one of these auxins at 5.0 μM shoot cultures produced microtubers weighing 300–400 mg fresh weight whilst kinetin, 6-(γ,γ-dimethylallylamino)-purine, 6-benzyladenine and abscisic acid failed to promote microtuber growth (microtubers weighed generally <200 mg). Media formulations Lloyd and MacCown and White supported the lowest frequencies of microtuber induction when kinetin was present at 2.5 μM. Anderson Rhododendron was as effective as Murashige and Skoog overall in promoting both microtuber induction and growth. When removed from cultures and planted in sterilized moist sand, microtubers sprouted readily (60–87% within 2 weeks) and produced vigorous shoot growth and after 5–7 months minitubers of sizes (30–80 g) suitable for direct field planting.
TL;DR: This work has shown that there has been a steady decline in the number of micropropagation laboratories in the 1990s, which was at least partially caused by the inability of laboratories to reduce contamination losses to a level which allows a predictable production output and quality of microPropagated plants.
Abstract: Microbial contamination is the single most important cause of losses in commercial and scientific plant tissue culture laboratories [1,2]. However, even in commercial companies the severity and implications of the problem are not recognised or admitted. Many scientific laboratories fail to record contamination losses, and the micropropagation industry often only recognises the sources of contamination after severe losses have occurred. Following a rapid increase in the production of micropropagated plants in the 1980s [3], there has been a steady decline in the number of micropropagation laboratories in the 1990s, which was at least partially caused by the inability of laboratories to reduce contamination losses to a level which allows a predictable production output and quality of micropropagated plants.
TL;DR: Overall, embryogenic competence showed a correlation with photoequ equilibrium, and Phytochrome appeared to be inductive although this effect was adversely influenced by the blue absorbing photoreceptor, in particular at low photoequilibrium.
Abstract: The effect of light quality on somatic embryogenesis in quince BA 29 was investigated. 2,4-D induced leaves were exposed for 25 days to the following light quality treatments: dark, far-red, far-red+blue, far-red+red, blue, white, red+blue, red. After a further 20 days of white light exposure, somatic embryo production was recorded. Somatic embryogenesis was highest in cultures subjected to red light treatment, and decreased progressively with the transition to red+blue and to white. Overall, embryogenic competence showed a correlation with photoequilibrium. Phytochrome appeared to be inductive although this effect was adversely influenced by the blue absorbing photoreceptor, in particular at low photoequilibrium. Independently of light treatments applied, somatic embryos frequently showed severe morphological abnormalities. Conversion of somatic embryos to plantlets was not observed.
TL;DR: Shot tips of Musa acuminata cultivar ‘Grande Naine’ were cultured in a non-controlled natural light environment at the IAEA Laboratories, Austria during summertime and rooted plantlets showed 100% survival during acclimatisation and normal development.
Abstract: The concept of using sunlight for micropropagation systems is proposed as a way of reducing tissue culture costs. Shoot tips of Musa acuminata cultivar ‘Grande Naine’ were cultured in a non-controlled natural light environment at the IAEA Laboratories, Austria during summertime. Significantly more shoots were produced by plantlets cultivated in a sunlit room with photosynthetic photon flux densities (PPFD) fluctuating up to 570 μmol m-2 s-1, temperatures between 23 and 30 °C and photoperiods of 12 to 16-h, than by plantlets under artificial light in a growth chamber providing controlled conditions of a constant PPFD of 65 μmol m-2 s-1, temperatures ranging from 23 to 29 °C and a 16-h photoperiod. Highest multiplication rates were achieved in a greenhouse with PPFD reaching 860 μmol m-2 s-1 and temperatures of 18 – 43 °C, but browning of leaves and loss of turgor occurred. Nevertheless, rooted plantlets showed 100% survival during acclimatisation and normal development. Photoperiods of 12 – 16 h did not affect the multiplication rates.
TL;DR: Whole plants, regenerated from salt tolerant callus, exhibited salt stress tolerance as evidenced by their higher fresh and dry weights when watered with 90 mM NaCl, and they also produced more tubers per plant under salt stress.
Abstract: A stable salt-tolerant potato cell line, able to grow on media containing 60–450 mM NaCl (i.e. low to high salinity) was selected. Callus grown on 120 or 150 mM NaCl showed higher fresh weights than the rest of the treatments. Replacing NaCl by KCl or Na2SO4 showed that reductions in fresh weight were mainly due to the presence of Na+ ions. When PEG 6000 was added to the medium instead of salt, the salt tolerant cell lines were unable to overcome the PEG-induced water stress. Whole plants, regenerated from salt tolerant callus, exhibited salt stress tolerance as evidenced by their higher fresh and dry weights when watered with 90 mM NaCl, and they also produced more tubers per plant under salt stress. Salt-tolerant plants differed phenotypically from control plants both in terms of leaf shape, tuber flesh and skin colour, which was reddish. In addition, DNA fingerprinting by RAPDs, with 70 different primers, confirmed that the salt tolerant regenerants also differed genotypically from the control, salt sensitive Kennebec potato plants from which they had been selected.
TL;DR: It appears that EBR does not always act directly on stem elongation but may be an elicitor and/or an enhancer of elongation in concert with endogenous and other exogenously added growth regulators.
Abstract: In vitro regeneration of sweet pepper (Capsicum annuum L. cvs Jupiter and Pimiento Perfection) has been performed via direct organogenesis. The resulting shoot-buds were placed on media containing 24-epi-brassinolide (EBR) 0.1 μM, a plant steroid lactone, in the presence or absence of zeatin 9.1 μM plus GA3 5.2 μM for further stem elongation. Different responses to these treatments were recorded depending upon the protocols used and the genotypes tested. It appears that EBR does not always act directly on stem elongation but may be an elicitor and/or an enhancer of elongation in concert with endogenous and other exogenously added growth regulators. Elongated shoots were easily rooted with alpha-naphtalenacetic acid 0.5 μM (0.1 mgl-1) and transfered to soil, and following acclimation were taken to maturity in the greenhouse.
TL;DR: Callus induction and propagation were largely determined by the concentration of 2,4-dichlorophenoxyacetic acid whereas subspecies, cultivar, sucrose concentration and basal media were of less importance.
Abstract: A systematic study on the effects of subspecies, cultivar, basal medium, sucrose concentration and 2,4-dichlorophenoxyacetic acid concentration on callus induction, propagation and subsequent plant regeneration in Allium cepa has been carried out. Mature zygotic embryos from two onion (cvs. Sturon and Hyton) and two shallot (cvs. Tropix and Atlas) varieties were used as explants. After callus initiation and growth on both Murashige and Skoog (MS) and Gamborg's B5 modified by Dunstan and Short (BDS) basal media with different 2,4-dichlorophenoxyacetic acid and sucrose concentrations for eight weeks, lines were identified on which compact or friable callus was induced. Callus induction and propagation were largely determined by the concentration of 2,4-dichlorophenoxyacetic acid whereas subspecies, cultivar, sucrose concentration and basal media were of less importance. After callus propagation for twelve weeks, 315 lines from a total of 3348 embryos initially subcultured were selected to test their regeneration capacity on growth regulator-free medium. It was found that shallot formed more shoots and roots than onion. The MS basal medium proved to be more beneficial for shoot regeneration and root formation than the BDS basal medium. There were no differences in plant regeneration among selected calli which had been previously subcultured on different concentrations of 2,4-dichlorophenoxyacetic acid and sucrose. The results show that plant regeneration strongly depended on the line: 45.4% from 315 tested lines could produce shoots while 93.0% formed roots.
TL;DR: Antibiotic or other treatments may be needed to eliminate persistent microbial contamination, but the type and level of antibiotics and the duration of treatment useful for different plant tissue cultures vary and therefore need to be determined before use.
Abstract: Commercial micropropagation laboratories very often report that persistent bacterial and fungal contamination is a serious problem [1–3] Failure of surface sterilization procedures to produce aseptic cultures is a problem especially with woody plants Isolated meristems [4] and explants from stock plants grown under controlled conditions [5] have been used to obtain aseptic cultures for some plants Contamination is not always seen at the culture establishment stage; some internal contaminants become evident at later subcultures and are difficult to eliminate [6] Detection at an early stage can aid in selecting bacteria-free cultures [7] Antibiotic or other treatments may be needed to eliminate persistent microbial contamination [8–11], but the type and level of antibiotics and the duration of treatment useful for different plant tissue cultures vary and therefore need to be determined before use [11,12]
TL;DR: Morinda elliptica (Rubiaceae) cell suspension cultures were established in shake flask system for the production of anthraquinones and Murashige and Skoog's basal medium was found to be the best medium, at the range of sucrose concentration tested, 8% was the best in enhancing both cell growth and Anthraquinone production.
Abstract: Morinda elliptica (Rubiaceae) cell suspension cultures were established in shake flask system for the production of anthraquinones. The optimized medium formulation for cell growth and anthraquinone production is proposed. Murashige and Skoog's basal medium (MS) was found to be the best medium, used in combination with 0.5 mg l-1 NAA and 0.5 mg l-1 kinetin. At the range of sucrose concentration tested (3–8% w/v), 8% was the best in enhancing both cell growth and anthraquinone production. A strategy to formulate growth and production medium by manipulating culture age and inoculum age, the type of medium formulation used to grow inoculum, incubation temperature and light intensity was established. By using 18 month old culture and 7 day old inoculum at incubation temperature of 27 ± 3 °C, anthraquinone yield of 2.9 g l-1 and 4.5 g l-1, under illumination of 1200 lux and in the dark was obtained, respectively.
TL;DR: The cytological study revealed that one third of examined plants were haploid and the others were double haploid, and data indicated that the most plantlets per 100 cultured ovules resulted from the ovule of ovaries without cold treatment, when cultured in MS medium supplemented with 1 or 5 mg l−12,4-D.
Abstract: Ovaries from squash plants (cv. Eskandarani) were picked one day before anthesis, and exposed to cold temperature (4 °C) for 0, 2, 4 and 8 days. The ovules were cultured on MS medium with 30 g l−1sucrose, 8 g l−1agar and supplemented with four concentrations of 2,4-D, i.e., 0.1, 1.0, 5 and 10 mg l−1. Then the dishes were incubated at 25 ± 1 °C under 16-h photoperiod for 4 weeks. After that ovules were transferred to growth regulator free MS medium for 4 weeks. Data indicated that the most plantlets per 100 cultured ovules resulted from the ovule of ovaries without cold treatment, when cultured in MS medium supplemented with 1 or 5 mg l−12,4-D. The cytological study revealed that one third of examined plants were haploid (2n = x = 20) and the others were double haploid (2n = 2x = 40).
TL;DR: Callus induction and in vitro plantlet regeneration systems for safflower using root, hypocotyl, cotyledon and leaf explants were optimized by studying the influence on organogenesis of seedling age, media factors, growth regulators and excision orientation.
Abstract: Callus induction and in vitro plantlet regeneration systems for safflower (Carthamus tinctorius L) cv Bhima using root, hypocotyl, cotyledon and leaf explants were optimized by studying the influence on organogenesis of seedling age, media factors, growth regulators and excision orientation Supplementation of the medium with an auxin: cytokinin ratio 134–1141 μM concentrations of growth regulators (IAA, NAA, BA and Kinetin) in the medium were found effective for callus induction and regeneration in all explants The calli could be maintained over 32 months BA (443 μM) combined with casein hydrolysate (10 mg l-1) yielded the highest rate of shoot production on hypocotyl (3–6) and cotyledon (5–7) explants and cotyledonary derived callus (4–8) More shoots were produced on explants cut from the most basal region of cotyledons from 5 to 7-day-old seedlings than from older seedlings or more distal cut sites Apolar placement of explants, inhibited shoot regeneration The shoot regeneration potential remained upto 7 months in calli developed on NAA + BA Of three media tested, MS was superior to SH-M and B5 Rooting of shoots was not efficient; 42% of the shoots were rooted on MS medium containing sucrose (7–8%) + IAA (28–57 μM) Capitula induction was observed in both callus mediated shoots on cotyledons and shoots on rooting medium with sucrose, IAA, NAA and IBA Well developed plantlets were transferred to the field with a 34% success rate
TL;DR: Regenerated plantlets could be sucessfully transferred to soil where they grew well within 10–12 weeks with 80% survivality and shoot proliferation could be continued even after a year by transferring each divided shoot explant to the same medium.
Abstract: Emerging buds of rhizome of Alpinia galanga Willd produced shoots and roots simultaneously when cultured in MS medium supplemented with kinetin 3.0 mg l-1. Each explanted shoot bud produced 8 shoots in average and roots simultaneously within 8 weeks. Shoot proliferation could be continued even after a year by transferring each divided shoot explant to the same medium. Regenerated plantlets could be sucessfully transferred to soil where they grew well within 10–12 weeks with 80% survivality.
TL;DR: It is concluded that changes in the measured parameters, observed under tuberizing conditions, are specifically related to the formation of the tuber, and are confined to the swelling part only.
Abstract: The development of axillary buds of potato (Solanum tuberosum L.) plants, cultured in vitro, was analyzed. Depending on the composition of the culture medium, the buds developed into either tubers (medium with 8% sucrose), shoots (1% sucrose), or stolons (8% sucrose and 0.5 μM gibberellin). Endogenous sugar and starch levels, and key-enzymes involved in the conversion of sucrose to starch were determined at different stages of development. Moreover, the spatial distribution of sugar levels and enzyme activities were determined within the developing structures. Glucose and fructose decreased upon tuber formation, most noticeably in the swelling parts, where also starch accumulated. The activities of sucrose synthase, fructokinase and ADP-glucose pyrophosphorylase were highest under tuber-inducing conditions, the increase being confined to the tubers, and absent in the subtending stolons. It is concluded that changes in the measured parameters, observed under tuberizing conditions, are specifically related to the formation of the tuber, and are confined to the swelling part only.
TL;DR: In vitro regeneration of adventious shoots from cultured leaves of Japanese pear (Pyrus pyrifolia) achieved from six cultivars and frequency of regeneration per leaf was as high as 23% but cultivar and environmental factors influenced the result.
Abstract: Several experiments were conducted to investigate in vitro regeneration of adventious shoots from cultured leaves of Japanese pear (Pyrus pyrifolia). A protocol was developed and regeneration achieved from six cultivars. Leaves harvested from shoot cultures which had been preconditioned on B5 medium with 5 μM thidiazuron plus 0.25 μM gibberellic acid were placed on regeneration medium of the same composition. Frequency of regeneration per leaf was as high as 23% but cultivar and environmental factors influenced the result. More mature (basal) leaves regenerated more frequently than younger ones from the shoot tip. Leaf orientation during regeneration and photoperiod was not a strong influence but regeneration from leaf pieces was less than from uncut leaves. An alternative regeneration procedure was developed in which first, shoot cultures were grown on the preconditioning medium. Leaves of the intact shoot cultures were then induced to regenerate directly when adventitious shoots formed on leaves of the intact shoot culture leaves without excision. Adventitious shoots from both procedures developed into typical shoot cultures when transferred to shoot culture maintenance medium.
TL;DR: Three different types of morphogenesis were identified in embryogenic cultures of Prunus avium grown on a proliferation medium containing 0.54 μM NAA, 0.46 μM kinetin and 0.44 μM BA: a friable hyperhydric callus, repetitive embryogenesis and an embryogenic tissue.
Abstract: Three different types of morphogenesis were identified in embryogenic cultures of Prunus avium grown on a proliferation medium containing 0.54 μM NAA, 0.46 μM kinetin and 0.44 μM BA: a friable hyperhydric callus, repetitive embryogenesis and an embryogenic tissue. Translucent and white somatic embryos were produced from the three types of morphogenesis but mainly from the embryogenic tissue. These somatic embryos showed histological and cytological teratological features such as highly differentiated cells with shrunken cytoplasm and destructured nuclei. For the four lines studied, somatic embryo production was improved by transferring the embryogenic tissue to developmental media without auxin and cytokinin but supplemented with maltose alone or maltose and 10 μM ABA. Three weeks after transfer, the line showing the most embryogenesis produced 1404 somatic embryos per gram of embryogenic tissue. A concentration of 263 mM maltose significantly increased the number of white somatic embryos for L 10 line, while translucent somatic embryo production was improved by 88 mM maltose for L 16 line. The combination of maltose and ABA produced different effects with each line. When used with 88 mM maltose, 10 μM ABA significantly increased white somatic embryo production for two lines but decreased the production for one line. When combined with 263 mM maltose, ABA had no effect on white somatic embryo production but significantly decreased the number of translucent somatic embryos. Cells of white somatic embryos contained protein storage reserves and numerous lipid bodies, while those of translucent embryos did not contain storage reserves or lipid bodies. After a two-month cold treatment conversion rate of white and translucent somatic embryos reached 8.5% and 35.2% respectively.
TL;DR: The results revealed ten diploid and ten haploid plants of a summer squash cultivar through anther culture supplemented with sucrose and 2,4-D combinations, with the most plantlets resulted from the induction medium supplemented with 150 g l−1sucrose and 5 mg l−12, 4-D.
Abstract: This work was conducted to study the effect of sucrose and 2,4-D combinations on induction of haploid plants of a summer squash cultivar through anther culture; therefore, sucrose was used at 30, 60, 90, 120 and 150 g l−1and 2, 4-D was used at 0.1, 1.0, 2.5 and 5.0 mg l−1on solid MS anther culture medium. Anthers at the mid or late uninucleate microspore stage without filament were excised from sterilized buds and plated on 20 different induction media. The most plantlets resulted from the induction medium supplemented with 150 g l−1sucrose and 5 mg l−12, 4-D. Root tips from 20 plantlets were cytologically examined under a light microscope. The results revealed ten diploid (2n>= 2x= 40) and ten haploid (2n= x= 20) plants.
TL;DR: Different pretreatments were given to anthers of barley before culturing, and their effects assessed on the frequency of embryos and green doubled haploid plants produced, with Mannitol pretreatment better than cold pretreatment for some low responding cultivars.
Abstract: Different pretreatments were given to anthers of barley before culturing, and their effects assessed on the frequency of embryos and green doubled haploid plants produced. Mannitol pretreatment was better than cold pretreatment for some low responding cultivars. Optimal concentration of mannitol for pretreatment depended on cultivar. Low responding genotypes needed a higher concentration of mannitol than responsive ones. The addition of Ficoll to liquid medium increased the number of embryos and green plants. The influence of the growth regulators 2,4-D and TIBA was assayed using ten cultivars of barley grown in Spain. The anti-auxin TIBA gave good embryo production with some of the low responding cultivars. Two row-type cultivars always produced higher number of embryos and green plantlets than six row-type. The application of these modifications to 10 F1 hybrids with potential agronomic value, allowed the production of almost 1000 doubled haploid plants from only 3500 anthers. Up to two doubled haploid plants per flower were produced from the cross Monlon × Sonja.
TL;DR: In Cu-tolerant plants, dry matter production was higher than in controls, particularly in roots, and no difference as far chlorophyll content and chloroplast structure was found among Cu-Tolerant and control plants.
Abstract: In Nicotiana tabacum L. var. BEL W3 copper (Cu) at concentrations higher than 50 μM significantly inhibited callus growth and shoot regeneration. After 5–6 months of culture only a few morphogenic callus lines survived in the presence of 100 μM Cu. These calluses showed the capacity to grow and regenerate shoots through successive subcultures on medium containing 100 μM Cu. The 100 μM Cu-tolerant shoots, in comparison to regenerated control shoots, formed roots only when cultured in the presence of 100 μM Cu. From five independent Cu-tolerant callus lines in a culture period of 4–5 months more than 50 plants (defined ‘tolerant’) able to grow in presence of 100 μM Cu were obtained. These plants showed normal xylem tissue formation while control regenerated plants growing in normal Cu MS content (0.1 μM) had few xylem elements in the central cylinder. No difference as far chlorophyll content and chloroplast structure was found among Cu-tolerant and control plants. In Cu-tolerant plants, dry matter production was higher than in controls, particularly in roots.
TL;DR: Hyssopus officinalis transformed roots were induced by infection with Agrobacterium rhizogenes growing well in hormone-free Woody Plant liquid medium producing high levels of phenolic compounds such as rosmarinic acid and lithospermic acid B.
Abstract: Hyssopus officinalis transformed roots were induced by infection with Agrobacterium rhizogenes. The transformed roots grew well in hormone-free Woody Plant liquid medium producing high levels of phenolic compounds such as rosmarinic acid (maximum: 8.03% of dry weight) and lithospermic acid B (maximum: 3.89% of dry weight).
TL;DR: An efficient plant regeneration system was developed for the induction of direct shoot formation from leaves derived from seedlings of Neoregelia cruenta, an endemic Bromeliaceae of Eastern Brazil, and shoot differentiation occurred directly from the leaf bases.
Abstract: An efficient plant regeneration system was developed for the induction of direct shoot formation from leaves derived from seedlings of Neoregelia cruenta, an endemic Bromeliaceae of Eastern Brazil. Shoot differentiation occurred directly from the leaf bases. In vitro responses were influenced by seedling age and growth regulator combinations. Highest regeneration rates were obtained from explants excised from 7-week-old seedlings cultured in the presence of 22 μM BA and 2.5 μM NAA. Shoot conversion to whole plants was most effective in shoots formed in response to 4.4 or 8.8 μM BA combined with 2.5 μM NAA.