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The experiments were carried out on highbush blueberry 'Herbert' both on in vi­tro cultures and plants in vivo. In the case of the in vitro study, the modified Zim­merman and Broome (1980) medium was used. For the first subculture dikegulac was tested at a 0.1-10 mgl-1 concentration together with 2iP (5mgl-1). For the second subculture, dikegulac (1-4mgl-1) was added both into medium supplemented with 2iP (10 mgl-1), and into medium without 2iP. In the case of the in vivo study, dikegu­lac (100-1000 mg l-1) was applied as a foliar spray on four-month old plantlets. Dikegulac (0.1-5 mg l-1) gradually slowed down the elongation of axillary shoots in vitro, in the presence of 2iP at a lower (5 mg l-1) concentration. It also retarded devel­opment of adventitious shoots, while proliferation of axillary shoots was unaffected. Cultures grew very slowly when 2iP was omitted regardless of the concentration of the retardant Plants sprayed with dikegulac (1000 mg l-1) solution in vivo developed more lateral shoots which were shorter, and the plants had reduced leaf blades. Cut­tings collected from plants treated with retardant rooted better, compared with the control. Dikegulac may be useful to keep the germplasm bank and in propagation of highbush blueberry, both in vitro and through cuttings.
The influence of sucrose (5, 10, 20, 30 g l-1), nitrogen salts - KNO3, NH4NO3 (25%, 50%, 100% in relation to the MS medium) and temperature (15 °C, 20 °C) on the growth of the main shoot and the activation and development of axillary buds in Syringa vulgaris in vitro was investigated. Different ratios of sucrose/nitrogen salts in the MS medium had a limited effect on the length of the main shoot of lilac plantlets. Also, the concentration of sucrose and nitrogen salts in the medium did not signifi­cantly affect the formation of nodes on the main or axillary shoots. The outgrowth of axillary shoots depended on the sucrose and nitrogen salts concentrations and tem­perature. Among the various sucrose/nitrogen salts relations, the highest number of axillary shoots (4.2) was found in the plantlets growing at a temperature of 20 °C, on a medium with a low level of sucrose (5 g l-1) and 100% strength of KNO3 and NH4NO3. Increased levels of sucrose in the medium significantly reduced the devel­opment of axillary buds in lilac plantlets growing at either temperature. By contrast, high levels of sucrose increased the fresh weight of lilac shoots. Different levels of nitrogen salts in the medium containing the same level of sucrose had no significant effect on the fresh weight of lilac shoots. On the other hand, at all levels of sucrose, the increased strength of nitrogen salts in the culture medium significantly enhanced the emergence and growth of axillary shoots. Increased strength of nitrogen salts in the medium appeared to counteract, at least partially, the inhibitory effect of a high sucrose level on the growth of axillary buds in Syringa vulgaris. There was clearly an interaction between the levels of sucrose and nitrogen salts such that a medium with a low sucrose to nitrogen ratio promoted axillary branching, whereas a medium with a high sucrose to nitrogen ratio inhibited the growth of axillary shoots. The different ratios of sucrose/nitrogen salts in the MS medium and the temperature affected the morphology of lilac plantlets. Increased supply of sucrose strongly stimulated leafsurface area, but the levels of nitrogen salts had a limited effect on leaf size. The plant- lets cultured at a temperature of 15 °C had bigger leaves than the plantlets at 20 °C. Low-sucrose treatments, irrespective of the level of nitrogen salts, induced a compact and branched habit of shoots and inhibited root formation. Increasing sucrose content in the medium resulted in a spontaneous formation of roots on the plantlets cultured in the presence of low levels of nitrogen salts.
The total soluble sugar content and antioxidant enzyme activities were studied for the first time during axillary shoot formation in Magnolia × ‘Spectrum’ in vitro in response to BAP (0.3 mg lˉ¹), different levels of gibberellic acid (GA3; 0.0, 0.1, 0.5, 1.0 mg lˉ¹), sucrose (20 and 30 g lˉ¹) and nitrogen salts (KNO3/NH4NO3; 100/100% and 75/50% relative to MS medium). Among various GA3 and sucrose/nitrogen salts ratios, the most effective axillary multiplication (5.9 shoots/explant) and leaf formation (25.7 leaves per multiplied clumps) were obtained after addition of GA3 at 0.1 mg lˉ¹ to a BAP medium containing 20 g lˉ¹ sucrose and reduced levels of nitrogen salts (75% KNO3 and 50% NH4NO3). The addition of GA3 to the BAP medium enhanced shoot formation by 36% and leaf formation by 27%. The highest shoot formation capacity of M. × ‘Spectrum’ in vitro coincided with enhanced levels of soluble sugar and peroxidase (POD) activity. Increasing GA3 concentration from 0.1 to 1.0 mg lˉ¹ in the above medium resulted in inhibition of shoot and leaf formation and a decrease in the soluble sugar content. The influence of GA3 on the activities of catalase (CAT) and POD depended on its concentration and the levels of sucrose and nitrogen salts in the medium. The highest increase in CAT and POD activities, that coincided with the enhanced shoot formation capacity of M. × ‘Spectrum’ in vitro, was observed after addition of GA3 to the medium containing high levels of sucrose and nitrogen salts.
Roots of Codonopsis pilosula (Franch.) Nannf. are among the most popular Chinese herbal medicines, exhibiting various beneficial activities which support immunity and stress resistance. The plant shows high intraspecific genetic variation. There is a need for effective vegetative propagation methods yielding high and sustainable quality. Here we report a micropropagation method using axillary shoot proliferation. Nodal segments from aseptically germinated plants were inoculated on modified MS media enriched with different concentrations of cytokinins: benzyladenine, kinetin (1, 4, 10 or 20 μM) or thidiazuron (1, 4 or 8 μM), with or without the auxin NAA (1 μM). Axillary bud break was initiated most efficiently on media with 1 or 4 μM BA and 1μM NAA. Shoot number increased markedly in subsequent cycles of harvesting and transfer to fresh 1 μM BA and NAA medium, leading to the maximum 69 shoots (mean 38.16±4.35) from a single nodal explant in the fourth harvest. The shoots were successfully (>98% efficiency) rooted in MS medium containing high sucrose (60 g/L) and 5 μM IAA, and acclimatized to soil cultivation with a survival rate of 90%. These results can be used to establish a simple and commercially viable protocol for mass propagation of C. pilosula for plantations or breeding.
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In vitro propagation of Inula royleana DC.

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A micropropagation method, through axillary shoot proliferation, was elaborated for Inula royleana DC. (Asteraceae), a medicinal plant native of Himalaya. Primary explants (cotyledonary node explants) and secondary explants (node explants of in vitro regenerated shoots) of the plant, inoculated on MS medium supplemented with 0.1 μM NAA and 5.0 μM kinetin, regenerated 3.4 ± 1.2 and 5.1 ± 1.9 axillary shoots per explant, respectively. The regenerated shoots were easily rooting and adapting to growth in soil.
Prunus mume is one of the most popular landscape plants In China and Japan. A successful in vitro propagation system for six cultivars of Prunus mume has been developed by in vitro culture of nodal segments from seedling and mature plants. High multiplication rates (from 2.5 to 5.5) were achieved using modified MS media and WPM basic media supplemented with TDZ, BA, IBA, 2,4-D or NAA at concentrations adjusted for each cultivar. All the studied cultivars could be proliferated efficiently on WPM media supplemented with 2.2 µM TDZ, 2.2 µM BA and 2.5 µM IBA. Shoots were rooted on agar-gelled 1/2 MS or WPM basic media containing 2.5 or 5.0 µM IBA, and plantlets were transferred to pots after they had grown more than 3 roots and at least one root was more than 10 mm long. The effects of TDZ, media composition and different genotypes on shoot multiplication and growth were studied in detail. The genetic fidelity of the micropropagated plants from the ’Xuemei’ cultivar was examined using PCR-ISSR markers, and the results demonstrated complete genetic stability in the cloned plants.
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