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In vitro shoot multiplication of apple: comparative response of three rootstocks to cytokinines and auxin
36-39.Views:208Shoot 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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Vegetative and micropropagation potential of Piper guineense (Schumach and Thonn)
29-36Views:110The 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.
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Factors affecting rhizogenesis in vitro and acclimatisation of three cherry rootstocks
40-46.Views:127Factors affecting rhizogenesis in vitro and acclimatisation of three rootstocks of cherry, i.e. Mahaleb, Maxma-14 and Weiroot -10 were investigated.
Rooting was easily achieved within 2-4 weeks on MS-based liquid or agar-gelled media containing auxins IBA at conc. 0.49 or 2.45 pM or NAA at conc. of 0.49 pM. On liquid media with 2.45 pM IBA, a maximum rooting efficiency of 95-100% was obtained. However, high concentrations of auxin delayed the time of root initiation for 3-5 days.
Rooted plantlets were transplanted into pots with a mixture of 3:1 (v/v) peat:perlite and acclimatised gradually to field conditions with efficiency of 60%.
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Knot formation by Pseudomonas syringae subsp. savastanoi on the in vitro shoots of Sorbus redliana
59-62.Views:158Two 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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Morphological, physiological features and differences of Vriesea splendens ’Fire’ plants during in vitro multiplication and rooting
Views:114During 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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Determination of auxine content of soft wood cutted `Marianna GF8/1' (Prunus cerasifera x P. munsoniana) by High Performance Liquid Chromatography during rooting period
67-70.Views:126The content of different auxins of soft-wood cutted plum rootstock 'Marianna GF8/1' (Prunus cerasifera x P. munsoniana) was determined during the rooting period. The level of auxin-concentration (exogenous and endogenous) of basic and intemodal part of cuttings was determined by WATERS HPLC equipment every 7 days during rooting period. The lengths soft wood cuttings were app. 30 cm long. The basal part of shoots were treated with 2000 pg/g concentrated indole-butiryc acid in talcum powder. After treatment the cuttings were placed in propagation green-house under intermittent mist. The plant hormones were extracted by methanol the solution was cleaned by paper-filter, and further cleaned by centrifuge. The effluent was examined by reversed phase High Performance Liquid Chromatography, with WATERS 2487 dual detector at 220 am on Symmetry C18 4,6x 150 column. Recovery and reproducibility assessment indicates good accuracy and acceptable relative standard deviation (RSD) 5%. Linear responses (r20.997) for calibration curve was obtained with IAA, IPA and IBA standard in range, with a limit of quantification of 0.15 g•m1-1. The concentration of IAA, IPA and IBA in the basal part of cuttings were measured, during the rooting period. We proved the external IBA was taken up by the plants. In the plants were found the IBA, and the IAA concentration of IBA treated cuttings was higher, than the untreated one.
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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:208Rooting 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.
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Nutritional and seasonal requirements for callus growth in Taxus baccata
111-114.Views:114Callus cultures derived from young stems of two varieties of Taxus baccata cv. aureovariegata (genotype I) and Taxus baccata L. (genotype II, III) were induced. Gamborg's B5 medium was supplemented with different concentrations of auxin (2,4-D) in combination with cytokinins (kinetin or topolin) and with a phenolic-binding compound (PVP) to prevent callus darkening and growth inhibition. Stem explants displayed different responses to in vitro culture depending on plant genotype and on the season. Genetic variability was observed in the growth rate of calli initiated from all three genotypes of the same Taxus species. We found the best growth of callus cultures originated from the genotype ill in defined media. After the first subculture the majority of the cream-coloured primary callus turned brown and ceased its growth. However, the long-term culture was initiated.