The process of in vitro rooting and the anatomical characters of in vitro and ex vitro leaves and roots of Prunus x davidopersica 'Piroska' were studied. Best rooting percentage (50%) and highest root number (5.0) was achieved in spring on a medium containing 0.1 mg/I NAA + 30 g/1 glucose. At the end... of rooting the parenchyma of the in vitro leaves was more loose and spongy, than during the proliferation period. In the first newly developed leaf of an acclimatised plant, the parenchyma was much more developed, contained less row of cells and less air space too, compared to the leaves developed in the field. The in vitro developed root had a broad cortex and narrow vascular cylinder with less developed xylem elements, but at the end of the acclimatisation the vascular system became dominant in the root.
Rooting of in vitro 'Royal Gala' shoots was studied under different conditions of root induction and root elongation phase. The rooting capacity was affected by both rooting phases. Very high rooting percentage could be reached with both liquid and solid root induction media. Raising the temperature from 22 °C to 26 °C during root in...duction phase increased the rooting percentage. Presence of activated charcoal in root elongation media can affect the number of roots per rooted shoots and can increase the rooting percentage, the length of roots and the rate of survival depending also on other conditions during rooting. Presence of NAA in root elongation media reduced the number and the length of roots considerably. Favourable effect of activated charcoal on rooting was mainly due to adsorption of NAA.
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 ind...uction 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.
Some experience or details are introduced in connection with the nutrient uptake of micropropagated fruit trees in the different phase of the in vitro or ex vitro development. It can be stated, that the plants during the micropropagation procedure are overfed. Special careful nutrient supply is necessary during the acclimatiza...tion.
Explants 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 wa...s 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.
Eustoma grandiflorum (Raf.) Shinn. 'Echo' Fl cultivars ('Echo White', 'Echo Rose', 'Echo Blue', 'Echo Blue Picotee') were used and multiplication of shoots was evaluated on Murashige and Skoog (1962) basal medium with 11 g/1 agar-agar and 20 g/1 sucrose. To test the effect of BA different concentrations were added: 0.10, 0.25 mg/1 and...a culture medium without BA. Differentiation of roots was examined on Jámbor-Benczúr and Marta (1990) basal medium with the same concentration of agar-agar and sucrose. To examine the effect on rooting, various concentrations of NAA were used: 0.5, 1.0, 2.0, 3.0 mg/l. The pH was adjusted to 5.6 in every case using KOH. We studied the after-effect of different concentrations of BA during the acclimatisation. During the multiplication, the cultivar 'Echo White' formed the most shoots and the smallest leaves on the medium with 0.10 mg/1 BA. Fortunately, in the case of this cultivar, the number of shoots was reduced and the length of leaves was increased succesfully on the medium without BA. The other three cultivars developed the longest leaves on the medium containing 0.10 mg/1 BA. Sometimes not only shoot regeneration but spontaneous rooting was observed during the multiplication. Examining the rooting, the highest percent of roots was found on the medium with 1.0 mg/1 NAA, and the cultivar 'Echo Rose' formed the most roots on this medium. Higher concentration (2.0 and 3.0 mg/1) of NAA already reduced the number of roots in all of the cultivars. During the acclimatisation, the percentage of survival was 76.3% and the tallest plants with the longest leaves were found on the multiplication medium with 0.25 mg/1 BA. 'Echo Blue Picotee' gave the best results with the tallest pieces and longest leaves on this medium.
The effects of the ethylene precursor ACC and two inhibitors, AgNO3 and AVG, on root formation were tested in in vitro shoots of passion fruit (Passiflora Midis f.flavicalpa Deg.). The organogenic response was assessed on the basis of percentage of shoot-forming. roots, root number and length. The time course of eth...ylene production was also monitored. ACC inhibited root formation by delaying root emergence and increasine, callus formation at the basis of the shoots. In addition, ACC caused a marked increase in ethylene production, coupled to leaf chlorosis and senescence with lower rooting frequencies, number and length of roots. IAA supplementation increased ethylene production. Both ethylene inhibitors, AgNO3 and AVG, at appropriate concentrations reduced callus formation at the basis of shoots. AVG increased the number of roots per shoot, but drastically reduced length of differentiated roots. Regarding to leaf pigments, ACC promoted a marked reduction on carotenoids and total chlorophyll, whereas AVG and AgNO3 delayed explant senescence and pigments degradation, not differing from IAA supplemented and non-supplemented control treatments. The results confirm previous reports on the beneficial effects of ethylene inhibitors on in vitro rooting and suggest its reliability to be used as an alternative approach to evaluate sensitivity of Passiflora species to ethylene.
During in vitro multiplication of Hosta ‘Gold Drop’, 20 g l-1 sucrose, 5.5 g l-1 agar and 4 concentrations (0.1-0.8 ml l-1) of Ferbanat L, Kelpak, Pentakeep-V were added to half-strength Murashige and Skoog (MS) basal medium. As compared to the control and other biostimulators, plants with lower per...oxidase activity, larger fresh weight, more, longer shoots and roots, larger leaves were developed on medium containing Kelpak. The best concentration was 0.4 ml l-1 for in vitro rooting, shoot formation, plant weight and ex vitro chlorophyll, carotenoid level, peroxidase activity. Pentakeep was the less efficient biostimulator, increasing of its concentration mostly decreased root and shoot values (furthermore, abnormal callus formation was observed, as non-wanted effect), chlorophyll content and sizes (length, width) of leaves, not only during in vitro propagation but also (as after-effect) acclimatization because of the high mortality and weakly developed survivor plants.
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).
Factors 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%.
In vitro plant material of clones (Q. robur) NL 100 A (adult) and NL 100 R (rejuvenated) received from Germany (A. Meier-Dinkel, 1995) were used in these experiments. WPM medium was used for the multiplication phase. Plantlets were subcultured monthly. Differences in quality and colour of the adult and rejuvenated cultures ind...uced us to follow and compare the changes of mineral- and chlorophyll content and dry weight during the propagation phase. Mineral and chlorophyll content as well as dry weight were measured weekly on three samples during the subculture period.
In the case of propagation rates we stated, they were similar around the year, but both clones had a high peak in April. Examining the cation-content, we detected that, the plantlets had a highest quantity of several elements during the 2nd and 3rd week of subculture. The iron content was the highest in the 1st week and after that it decreased continuously. It is supposed, that the content of iron is not enough in the media. The chlorophyll content of the rejuvenated clone was higher than that of the adult one.
In the rooting experiments it was stated that, after one-week cold treatment the rooting ability was the best.
Rooting responses of rootstocks cvs. JTE-F1, M. 26 and MM. 106 were studied to different concentration of IBA in root induction media and to presence of activated charcoal in root elongation media. High rooting rate (>90%) could be achieved in cvs. JTE-H and M. 26, while cv. MM. 106 showed weak rooting ability at each IBA level tested. Incre...asing IBA content depressed the rooting only in cv. M. 26. Presence of activated charcoal decreased considerable the rooting rate in cv. M. 26 and decreased the number of roots in cvs. JTE-H and M. 26. These cultivars developed longer roots on media containing activated charcoal, while cv. MM. 106 did not showed any reaction for it.
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.