DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 5-6/2016 str. 69 <-- 69 --> PDF |
plant disinfection, and the main disinfecting solutions used in this study were: Tween 20, Domestos and Izosan G chlorine solutions, 70% ethyl alcohol, and sterile water supplemented with ascorbic acid and antibiotics. In this research, hypochlorite-based solutions Domestos and Izosan G were used for reasons of their lesser toxicity during handling. After disinfection, bud leaflets were unfolded under a binocular loupe and were severed from the nodals to a size of approximately 2 mm, which comprises the meristem and the first pair of leaflets. Ten explants from each cultivar were set up, and successful disinfection was expected to yield 50%, or five pure initial cultures. The clones were gradually introduced into the initial culture. A total of 23 clones were successfully introduced over the four seasons. The culture medium for the establishment of the initial culture of axillary and terminal meristems of wild cherry consisted of MS medium (Murashige and Skoog 1962), supplemented with: potassium chloride, potassium sulphate, biotin, riboflavin, folic acid, calcium pantothenate and glycine (Table 2). Myo-inositol was not included, and macroelements were in half-strength concentrations. The universal culture medium for axillary bud multiplication of all the 23 clones of wild cherry consisted of our own combination of MS (Murashige and Skoog 1962), LM (Lloyd and McCown 1981), WPM and OM (Rugini 1984) basal media, supplemented with Staba modified vitamins. Compositions of culture mediums for in vitro production of wild cherry per stage, as well as the plant hormones used in different stages of in vitro production are presented in tables 2 and 3. Different concentrations of growth regulators were tested and the formation of new shoots, multiplication rates and duration were monitored. Five plantlets from each clone were set up in each concentration and were replicated twice in order to reliably determine the effect of growth regulators. All mediums were supplemented with 6.5 g/L of agar, and saccharose as follows: initial culture, 25 g/L; axillary shoot multiplication, 30 g/L; shoot elongation 30 g/L; rooting of microplantlets, 20 g/L. Culture mediums used in micropropagation of wild cherry were prepared by dissolving all media components in a flask of distilled water placed on stirring/hot plate. All media were adjusted to pH 5.8 with NaOH, and autoclaved at 120 °C for 30 min. The acclimatization was carried out under greenhouse conditions where temperature, light, and air humidity were adequate for a gradual hardening of plantlets. The plants were planted into a Klasman growing medium placed in 30×50 polystyrene liner trays (containers) with 42 planting holes, at a temperature at the root base from 20 to 24 °C, relative humidity of 70 to 90% and daily light of 5,000-10,000 lux. Artificial light with 400 W mercury vapour lamps was used during short days. For further plant cultivation and growth, the average temperature was about 18 °C in winter and 25-28 °C in summer, with relative humidity of about 70%. RESULTS REZULTATI The use of the cytokinin Kinetin to stimulate axillary branching in the multiplication phase had a positive effect on the formation of morphologically regular, firm, |