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  • The effects of growth regulators in proliferation of Sorbus redliana 'Burokvölgy'
    77-83.
    Views:
    191

    The Hungarian cultivar Sorbus redliana 'Burokvölgy' was proliferated on Murashige and Skoog (MS, 1962) medium with half-strength macroelements and 100 mg/1 meso-inositol, 20 g/1 sucrose, 11 g/1 agar-agar. Different combinations of kinetin (KIN), metatopolin (mT), benzyladenine (BA), benzyladenine-ribosid (BAR) and indolebutiric acid (IBA) were tested, and pH was adjusted to 5.6 every case using KOH. The cultures were incubated at 20-24 °C in 8/16 hours dark/light photoperiod for 50-52 days. The main aim of our research was to find the optimal growth regulator and its optimum concentration. Purthermore, to determine the chlorophyll contents of the in vitro propagated plants' leaves. During the proliferation, the highest number of shoots were observed in the case of using BA + IBA, and on the medium containing 0.75 mg/I BA + 0.05 mg/1 IBA 8.93 shoots were found. The addition of KIN + IBA decreased the number of shoots and increased the sizes of leaves — the widest (11.2 mm) and longest (17.8 mm) leaves were obtained on the medium containing 1.00 mg/I KIN + 0.05 mg/1 IBA. The longest shoots (36.46 mm) were found in the case of applying 0.75 mg/1 BAR + 0.05 mg/I IBA. The BA + KIN + IBA combination resulted the shortest shoots. Sometimes not only shoot regeneration but spontaneous rooting was observed during the multiplication. The highest chlorophyll content (1.569 mg/g total chlorophyll, 1.132 mg/g chlorophyll-a, 0.437 mg/g chlorophyll-b) was obtained in the presence of 1.0 mg/I KIN + 0.05 mg/1 IBA.

  • Single and dual effects of different cytokinins on shoot multiplication of different apple scions
    76-78.
    Views:
    161

    Shoot multiplication responses of three apple scions to different concentrations of BA and BAR as single source of cytokinins and in combination with two concentrations of KIN were studied. The effects of hormones depended on genotype, type and interactions of different cytokinins. Use of BAR significantly enhanced the shoot multiplication of cv. Jonagold (6.5 shoots per explant). The multiplication rate of cv. Jonagold could not be improved by using the combination of BAR and KIN. The best proliferation was achieved by 1.0 mg 1-1 BA combined with 1.0 mg 1-1 KIN of cv. Prima..(8.1) and of cv. Galaxy (10.4).The effect of 0.5 mg 1-1 BA along with 1.5 mg 1-1 KIN was similar on multiplication rate (10.9) of cv. Galaxy.

  • Morphological, physiological features and differences of Vriesea splendens ’Fire’ plants during in vitro multiplication and rooting
    Views:
    114

    During in vitro multiplication and rooting of Vriesea splendens ’Fire’, 0.1, 0.2, 0.4 and 0.8 mg l-1 benzyladenine (BAP), benzyladenine-riboside (BAPR), kinetin (KIN), meta-topoline (MT), indole-butyric acid (IBA) and naphthalene-acetic acid (NAA) were added to basal Murashige and Skoog (1962) MS medium. As compared to the hormone-free control, plants developed significantly more shoots on medium supplemented with almost all cytokinins (excepting KIN), especially BAP resulted the highest multiplication up to almost 26 shoots. Enhancement of cytokinin concentrations increased shoot number (and in case of BAP, peroxidase activity) but decreased plant height and rooting parameters. Regarding root production, both auxins were definitely beneficial (0.2 mg l-1 NAA resulted more than 7.5 roots and higher auxin concentrations efficiently stimulate root elongation); however, KIN had similar effects. After a three-month duration time of acclimatization, we observed that plants which were previously cultured on medium containing certain cytokinins (KIN in all doses and 0.1 mg l-1 MT) or both auxins had greater survival, moreover, as negative after-effect, higher cytokinin concentrations reduced the number of survived specimens.

  • The effect of different cytokinins on chlorophyll content and morphological features of in vitro Nidularium ’Kertész Jubileum’
    47-51.
    Views:
    224

    During in vitro multiplication of Nidularium ‘Kertész Jubileum’, 20 g/l sucrose, 5 g/l agar, 100 mg/l inositol, and different concentrations of benzyladenine (BA), benzyladenine-riboside (BAR), kinetin (KIN), meta-topolin (mT) were added to the MKC (Knudson, 1946) basal medium. Furthermore, 0.1 mg/l naphthaleneacetic acid was used to every medium. Number of shoots, length of leaves, number and length of roots, chlorophyll (a+b) content were examined and evaluated with Ropstat statistical software. As compared to the other cytokinin, significantly most shoots were obtained in the case of applying BA. Increasing of BA-concentration (as far as 2 mg/l) enhanced shoot number (from 10.92 to 19.26) but 4 mg/l BA resulted only 6.63 shoot. The less efficient cytokinin was KIN, in most cases no more than about 2 shoot was achieved. Regarding the length of leaves, the higher level of BA effected averagely the shorter leaves (from 24,46 to 7.31 mm). KIN effected significantly the longest leaves (43.4-61.29) in inverse proportion to the concentration. The same cytokinin resulted the most (and the longest) roots with the highest rooting percentages, but more KIN decreased the number and length of roots (from 7.95 to 4.4 and from 38.49 to 22.73 mm). There were no definite correlation between cytokinin concentration and chlorophyll (a+b) content, but the highest doses resulted decreasing (except of meta-topolin which leads to the lowest values). Summarizing, BAR effected the highest contents (mostly more than 1400 μg/g), particularly in the case of 1 mg/l (1807.3 μg/g).

  • Production of transgenic bean callus via genetic transformation by DNA-coated tungsten particles
    43-47.
    Views:
    106

    Callus cultures were induced from hypocotyl of young bean seedlings. The B5 medium completed with 1 mg/1 KIN and 2mg/1 2,4-D proved the best. Callus developed and maintenaned on B5 medium supplemented with 1mg/1 kinetin and 2mg/I 2,4-D. The B5 medium supplemented with 1mg/1 KIN and 2mg/1 2,4-D induced much more callus than half strength MS medium supplemented with 0.5 or 0.75mg/1 BA and 0.1 mg/1 NAA. The results demonstrate that GeneboosterTM is convenient method to obtain transient gene expression in callus of bean. The results have shown that the bean callus shot by GeneboosterTM can be transformed to get (kanamycin-resistant and stress mannitol­tolerant) calli. The presence of mannitol-dehydrogenase gene (mt/) was verified by PCR, showing the integration of mt/ gene carried by two plasmids. Co-transformed calli were selected after bombardment on kanamycin, mannitol and (kanamycin+mannitop-containing media. Data of molecular analysis (PCR) confirmed the insertion of mtl gene in the genome of mannitol-tolerant callus lines.

  • Influence of aromatic cytokinins on shoot multiplication and their after-effects on rooting of apple cv. Húsvéti rozmaring
    84-87.
    Views:
    198

    Different aromatic cytokinins (BA, BAR, TOP and KIN) were tested alone or in combination for the shoot proliferation response of ‘Húsvéti rozmaring' apple scion. The best multiplication rate was achieved by dual cytokinin application (1 mg 1-1 BA + 1.5 mg 1-1 KIN). The rooting capacity was affected considerably by the position of shoots: transfer of the three-week-old shoots to the same or other proliferation medium in vertical position inhibited the following rooting totally. Post-effects of different cytokinins (BA and TOP) on subsequent rooting could be detected: BA increased the number of roots markedly, while TOP resulted in significantly longer roots.

  • Post-effects of cytokinins and auxin levels of proliferation media on rooting ability of in vitro apple shoots (Malus domestica Borkh.) 'Red Fuji'
    26-29.
    Views:
    206

    Rooting ability of in vitro apple shoots of 'Red Fuji' grown on proliferation media with different hormone content were tested at three IBA levels in root induction media. Rooting percentage could be slightly increased with an increase in IBA concentration in proliferation media. The highest IBA concentration (3.0 mg 1-1) in root induction media showed strong inhibitory effect on rooting capacity of in vitro shoots. The highest rooting percentage (95%) could be achieved by shoots grown on proliferation media containing TOP or BA+KIN as cytokinins before rooting.

     

  • Vegetative and micropropagation potential of Piper guineense (Schumach and Thonn)
    29-36
    Views:
    105

    The continuous loss of forest plants due to deforestation, and the increasing demand for Piper guineense because of its medicinal and food value, has put a permanent pressure on its population in the wild where it is collected. A method for conservation and mass propagation is therefore required. This research was undertaken to determine the optimal concentration of auxin needed for vegetative propagation and to investigate the potential of Piper guineense for micropropagation. The auxin optimization study of vegetative propagation was based on the use of two-nodal stem cuttings treated with five different concentrations of indole-butyric acid (IBA). Growth parameters such as the number of sprouted, rooted and survived cuttings among others were determined. To investigate the potential of Piper guineense for micropropagation, nodal explants were subjected to different sterilizing treatments using ethanol, NaOCl, mancozeb, streptomycin and Plant Preservative Mixture (PPM). The effect of plant growth regulators (PGRs) was tested on sterilized nodal explants using full strength Murashige and Skoog (MS) hormone-free media alone as control and MS media supplemented with PGRs (BA, NAA and KIN) at different concentrations and combinations. Significant differences were observed across the treatments for all growth parameters measured. However, 2000 ppm IBA significantly (p<0.05) influenced sprouting and rooting of the stem cuttings. Piper guineense explants have deep tissue contaminants, which cannot be eradicated by surface sterilization alone except double sterilization using PPM. On control media, neither shoot nor root response was observed while the highest percentage of induced roots was obtained from explants cultured on MS +1 mg/L BA + 0.25 mg/L NAA. Shoot induction was only achieved when BA was used alone and when subcultured on media supplemented with NAA, which generated roots.