We conducted experiments for developing an in vitro micropropagation protocol starting from meristems of Rudbeckia hirta L seedlings. We pre-soaked the seeds in sterile ion-exchanged water for 17 hours, and then achieved surface disinfection in two separate steps. First, we used concentrated household sodium-hypochloride solut...ion for 20 minutes and, also for 20 minutes, we applied hydrogen peroxide of 10%, which was followed by washing with sterile ion-exchanged water three times. For the propagation of seedling meristems, the combination of half-strenght solid Murashige and Skoog (1962) culture medium containing 10 mg/1 of kinetin or 2 mg/I of kinetin + 0.1 mg/1 of 2iP proved to be the most suitable. The average number of shoot-buds developed from the seedling axillary meristem in the best culture media varied between 5 and 17. Without separating them, we inoculated the shoot-bud clusters on MS culture medium containing 2 mg/1 of IAA. After four weeks of incubation we obtained elongated shoots which we separated and inoculated into a new culture medium and we obtained elongated roots. The rooted plants were gradually acclimatised in the cultivation room, potted and carried to a greenhouse, and then planted in open field for subsequent observation. By adopting this method, our laboratory started the micropropagation of the superior and/or elite genotypes of the Rudbeckia hirta L. being of special value in respect of breeding.
Mass propagation of 5 newly introduced Hosta varieties was carried out by the method of micropropagation. Our aim was to determine exact variety specificity after the micropropagation period in the pattern of peroxidase isoenzymes by isoelectric focusing in pH 3-9 range and to determine that phenological phase of mother plant in which...the isoenzyme pattern of mother plant can safely be comparable to the isoenzyme pattern of micropropagated descendants. The isoenzyme patterns of descendants were similar to the mother plants of the same hybrid lines. The older leaves seemed to be not so suitable for examination than newly developed ones despite of the higher activity of peroxidase enzymes. There were big differences in isoenzyme patterns of leaves in different phenological phases. With this quick and easy method Hosta varieties could be selected already in the very early stage of micropropagation.
This paper gives an outline of micropropagation of Pontederia lanceolata. Pontederia l. is a widely used aquatic plant, therefore there is an increasing demand for them, which can be satisfied only by in vitro culture. Research was carried out to find the best nutrient media conditions for micropropagation and acclimatisation of Po...ntederia lanceolata.
A simple and reliable procedure for in vitro propagation of an orchid Dendrobium strongylanthum Rchb.f. was studied. Protochorm was induced from seed explants on 1/2 MS medium supplemented with 0.2 mg/L NAA. A mass of protochorm could be multiplied on proliferated medium of 1/2 Ms containing 0.5 mg/L V-6-BA. And bud differenti...ation of green global body was cultured in the same media, 2-2.5 cm shoots were formed after 30 day of culture. Addition of mashed banana and 0.5 mg/L NAA to 1/2 MS medium promoted root formation and vigorous growth. The plantlets were acclimatized and transplanted to compound materials of humus:sawdust (1:1) in greenhouse, the survival rate was more than 98%.
The effect of seven concentrations of two carbohydrate sources were compared to determine the best source and the most suitable source and concentration for micropropagation of some Hosta cultivars: H. 'Gold Haze', H. 'Gold Drop' and H. 'Dew Drop'. 0, 5, 10, 20, 30, 40 and 50 g/1 sucrose or glucose were added to a MS...basic medium supplemented with 3 mg/1 kinetin and 0.1 mg/1 IAA. For 'Gold Haze' 40 g/1 sucrose proved to be the best source and concentration, the proliferation ratio was 15 shoots per explant. Thirty g/1 sucrose concentration was the optimum for 'Gold Drop', the proliferation rate was 14.6 shoots per explant. In 'Dew Drop,' the best results were obtained with 30 g/1 sucrose but 40 g/l sucrose gave good results too. Both cultivars rooted well on these media. On glucose containing media, very low propagation rates were found in all concentrations and all examined cultivars.
Callus formation, as a prerequisite for the induction of somaclonal variability, was achieved successfully with certain molar ratios between 2,4-dichlorophenoxyacetic acid and benzyladenine. Regeneration of new plants from shoot apex meristems could be significantly improved by the combined addition of very low amounts of indolebutiric acid, be...nzyladenine and gibberelic acid, dissolved in the Murashige-Skoog nutrient medium. These in vitro treatments may contribute to a more efficient micropropagation of the Rimini variety of carnation.
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.
In Hungary black locust (Robinia pseudoacacia L.) is considered as an important exotic stand-forming tree species and due to climate change effects its importance is increasing in many other countries. It has some desirable characteristics from both the practical and research standpoints. As a result of a partly new black locust selection progr...amme new black locust clones were improved and a technology was developed for mass clonal micropropagation of juvenile trees. Clone trials with micropropagated plants were established in the country for evaluating the juvenile growth and the stem form of promising black locust clones under marginal site conditions. Significant differences (P<5%) were found for stem form value which partly verified the genetic gain of the selected clones against the common black locust. It was also proved that tissue culture could offer partly new prospects for the rapid mass cloning of selected genotypes.