Marisia - Maros Megyei Múzeum Évkönyve 35/2. (2015)
Botany
Micropropagation of blackberry cultivars — perspectives for Republic of Moldova The shaped inoculums are inserted in tubes with the nutrient medium of MS 100% agarose gel, approximately 9-10 ml medium/tube. In the initiation phase, 50-85% of explants survived and generated plants. Depending on the cultivar, there were selected only the tubes in which the generated and transferred inoculums survived on nutrient media MS 100% with the addition of BAP 0.5mg/l. It was stated that in the multiplication phase of the thornless blackberry variety, the optimal type of inoculums are portions of shoots or shoots having 0,5-0,7cm in length. Nutrient media was prepared using micro- and macro stock solutions, vitamins. All components were added before autoclaving. The pH of the medium was adjusted to 5.8. The media was distributed in tubes made of glass, 15 ml of medium in each tube, and sterilized by autoclaving at temperature 120° C for 15 minutes. For the micropropagation of the micropropagula, the liquid medium MS was tested in two experimental variants: 100% and 50%. The first medium is being more often used to obtain increased amounts of plant material. The 50% option is used as a rooting medium, as well as a medium for preservation for a certain period. MS medium was tested with different additions, but the most efficient and effective for morphogenetic initiation of blackberry seedlings is the 100% MS with a 5.8 pH before autoclaving. Rootedness process initiation was observed within 14 days from the in vitro transfer in this nutrient medium, and in 20-30 days a significant plant growth is observed, which can be used as seedling material for a further layer while the lower part of the plant is being transferred to ex vitro (Photo 1). For further micro-propagation, we use as segment consisting of one or two internodes, the explant segment must be as vigorous and healthy so we can obtain a qualitative seedling material. The length of the cuttings for micropropagation is 2—2.5 cm. It is very important for the sprig to be vigorous, so the micro-propagation process will be successfully completed. Once the sprig has reached a length of 12-14 cm it is subject to cutting and eventually transferred to other nutritive media for further micro-propagation. Thus, the biological material efficiency increases 4-5 times within 30-40 days. The plants are grown in a room with 16-hour light photoperiodicity and 8 hours of darkness, with an average temperature of 23 ± 20°C. (Photo 1). Photo 1: The cultivation room, micro-propagation of the Loch Ness cultivar In order to keep the plants in liquid, paper filter pads are placed in the test tubes. It was determined that 100% MS medium, with a 5.8 pH before autoclaving, is an efficient and optimal medium for the morphogenetic seedling initiaton. A number of different nutrient media 11
