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The effect of different cytokinins on chlorophyll content and morphological features of in vitro Nidularium ’Kertész Jubileum’
47-51.Views:237During 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).
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In vitro shoot multiplication of apple: comparative response of three rootstocks to cytokinines and auxin
36-39.Views:237Shoot multiplication responses of rootstocks cvs. M.26, MM.106 and JTE-H to different concentration of BA, BAR and IBA in eight various combinations were tested on MS-medium. The effect of hormones depended on genotype, type of cytokinin and interaction of cytokinin and auxin. Shoot multiplication was significantly enhanced with the use of BAR as cytokinin. High multiplication rate could be achieved in cvs. M.26, MM.106 and JTE-H: 7.7, 6.9 and 9.9 shoots per explant, respectively.
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In vitro effect of different cytokinin types (BAP, TDZ) on two different Ocimum basilicum cultivars explants
15-20.Views:396Ocimum basilicum L. (sweet basil) is an economically and ethnobotanically important aromatic, medicinal, ornamental and culinary herb, with a very wide gene pool, that is sensitive to cold and prone to several plant pathogens that can demolish harvest and lessen yield. In this research, the effects of BAP (6-Benzylaminopurine) and TDZ (Thidiazuron) on different genotypes for in vitro cloning were determined, in order to provide a detailed protocol guide concerning Ocimum basilicum L. propagation. The results from the O. basilicum seed propagations revealed that the best condition for the secondary shoot growth is with 5.0 mg/l TDZ or 1.5 mg/l BAP on all types of explants except the root, the secondary root growth can be obtained on all types explant with any BAP concentration and all cytokinins can induce callus on all types of explants. On the whole, it shows that multiple secondary shoot induction and regeneration in Ocimum basilicum L. is regulated by appropriate cytokinin concentration.
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Cytokinins affect the stomatal conductance and CO2 exchange of in vitro apple leaves
25-28.Views:261Effects of different cytokinin supplies including two types of aromatic cytokinins, such as benzyl-adenine, and 3-hydroxybenzyladenine applied at two different concentrations (2.0 and 6.0 μM) were studied on water and gas exchange parameters in in vitro apple leaves of ‘Royal Gala’ and ‘Freedom’ scions after 3 weeks of culture. Cytokinin supply affected the stomatal conductance of water vapour, transpiration rate and the sub-stomatal CO2 concentration of leaves. Effect of cytokinin depended on its applied type and concentration, moreover on the apple scion. According to the results, the rate of CO2 exchange itself is not usable for characterization of function of photosynthetic apparatus of in vitro leaves. However, measurements of stomatal conductance of water vapour and transpiration rate seemed to be good indicators for stomatal behaviour of in vitro apple leaves.
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Morphological, physiological features and differences of Vriesea splendens ’Fire’ plants during in vitro multiplication and rooting
Views:119During 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.
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Effect of aromatic cytokinins and explant position on shoot multiplication of Asparagus offi cinalis L.
67-70.Views:251Asparagus offi cinalis has been widely studied, but little information is available about its in vitro response to exogenous cytokinin during shoot multiplication. To study the effects of different cytokinins on shoot multiplication of A. offi cinalis ‘Grolim’, in vitro culture was initiated from shoot segments cultured on media with Murashige and Skoog medium. Effects of different aromatic cytokinins (6-benzylaminopurine, 6-benzylaminopurine riboside and meta-topolin) applied in four concentrations (0.5, 1.0, 1.5, 2.0 mg/l) on shoot multiplication of ‘Grolim’ were tested. Effect of explant position (vertically or horizontally) on the shoot multiplication outcome was also studied. Both the length and the number of newly developed shoots were signifi cantly affected by explant position and cytokinin content of the medium. The highest numbers of shoots (4.9) were produced in the presence of 0.5 mg l-1 6-benzylaminopurine riboside when explants were paced horizontally onto the medium. Although the longest shoots (41.5 mm) developed on explants placed vertically onto medium supplemented with 2.0 mg l-1 meta-topolin, the lengths of shoots developed on medium with 0.5 mg l-1 6-benzylaminopurine riboside were also adequate in both explant position (29.5 and 33.6 mm placed horizontally and vertically, respectively).
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Knot formation by Pseudomonas syringae subsp. savastanoi on the in vitro shoots of Sorbus redliana
59-62.Views:171Two strains of Pseudomonas syringae subsp. savastanoi were isolated from Forsythia sp. and Nerium oleander in Hungary in 1997. The effects of growth regulators produced by the bacteria were studied in different experiments. The strains were co-cultured with Sorbus redliana in vitro shoots without being in contact with the plant on solid media. Further culture filtrates in different concentrations were added to the culture medium. The growth regulators presented in the agar caused knot formation on the shoots and on the leaves in both kinds of culture. There were significant differences in the cultural and physiological characters, auxin and cytokinin activity of the strains of different origin.
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Development of in vitro propagation system for Atriplex halimus L.
123-129.Views:218Explants excised from adult shrubs were surface sterilized and cultured on Murashige and Skoog (MS) basal medium in the presence of plant growth regulators (PGRs) at different concentrations. A high multiplication rate of 7.2-fold was achieved every four weeks on MS medium supplemented with 4.44 μM BA, 0.49 μM IBA and 0.58 μM GA3. Rooting was achieved with 73% efficiency within 2-4 weeks on agar-gelled MS basal medium free of PGRs. Rooted plantlets were gradually acclimatized to field conditions over 5-6 weeks with 65% efficiency. For in vitro selection for salt tolerance, MS medium was supplemented with increasing concentrations of NaCl ranging between 25 and 1000 mM. This study has demonstrated that in vitro shoots could tolerate up to 600 mM NaCl with optimal growth at 200 mM, while higher concentrations of NaCl affected growth negatively. Growth and shoot number decreased with increasing NaCl concentration with all plantlets died at 1000 mM NaCl.
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Effects of aromatic cytokinins on structural characteristics of leaves and their post- effects on subsequent shoot regeneration from in vitro apple leaves of 'Royal Gala'
41-46.Views:173The effects of different aromatic cytokinins applied in different concentrations and combinations were investigated on the histology of in vitro apple leaves and their post-effects on subsequent shoot regeneration from these leaves were studied. Great differences in the anatomical structure of leaves could be detected originating from media containing different types and concentrations of aromatic cytokinins. The number of regenerated shoots per explant and the organogenetic index were used for the evaluation of the post-effect of aromatic cytokinins on shoot regeneration. The histological structure of leaves used for regeneration and their regeneration response showed a good correlation. When the pre-treatment caused a juvenile-like or less-differentiated structure, the number of regenerated shoots per explant increased and often vitrification also decreased and consequently the organogenetic index also increased. A strong interaction between cytokinin-content (type and concentration) of the pre-treatment medium and that of the regeneration medium could also be detected.
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Influence of aromatic cytokinins on shoot multiplication and their after-effects on rooting of apple cv. Húsvéti rozmaring
84-87.Views:219Different 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.