Wild roses are an important group of plants used as decorative shrubs and cut flowers. They are also a row material for pharmaceutical, cosmetic and food industries. For rose in vitro propagation, solid media are commonly used. Up till now there is a few reports confirming the beneficial effect of liquid media on Rosa shoot growth and multiplication. The aim of the study was to investigate different culture systems, temporary immersion system (TIS) (immersion frequencies of 15 min every 6, 8 and 12 h), rotary shaker (RS) and stationary liquid (SL) for propagation of R. canina and compare with solid medium culture. Shoot tips and stem explants were grown on basic Murashige and Skoog medium with 20 mg dm-3 Fe EDDHA, 1 µM BA, 1.5 µM GA3 and 3% sucrose for six weeks. Liquid cultures stimulated biomass growth. The highest biomass growth in RS cultures were observed however, RS reduced the shoot dry mass content. TIS cultures immersed every 6 and 8 h increased dry mass content. In TIS and on solid medium shoot multiplication was 1.5-2 times better than in other systems and stem explants were more efficient. Solid medium improved the content of chlorophyll a, b, a+b and carotenoids. Higher contents of photosynthetic pigments were determined in shoot tips than stem explants. TIS-derived plantlets accumulated the largest amount of phenolic compounds. As the frequency of immersion increases the concentration of these compounds were reduced. In turn, SL cultures favored the accumulation of soluble sugars.

ISHS International Symposium on Methods and Markers for Quality Assurance in Micropropagation LIGHT EFFECTS ON ORNAMENTAL MICROPLANT SHOOTS AND BULBS QUALITY

Liquid culture systems, including bioreactors, are valuable tools for the scaling up of production. Their involvement leads to the automation of the highly efficient, reproducible somatic embryogenesis of Narcissus L. ‘Carlton’. Alternative procedures for efficient embryogenic tissue and early somatic embryo multiplication have been developed. The long-term embryogenic callus of narcissus ‘Carlton’, obtained by repetitive somatic embryogenesis, was multiplicated and differentiated in different liquid culture systems. For multiplication, the Rita^® temporary immersion bioreactor and the rotary shaker at 60 rpm and 100 rpm were used, and, for differentiation, the rotary shaker at 60 rpm and solid cultures were investigated. Cultures immersed with a frequency of 15 min every 24 h during multiplication were characterized by the greatest increase in biomass (1.3), and the greatest number of embryos (152.6 embryos per 1 g of inoculum) was seen during differentiation. Higher immersion frequencies (15 min every 8 and 12 h) decreased the tissue quality and yield. The use of a bioreactor during multiplication promoted the number of embryos obtained during differentiation. In turn, cultivation in a rotary shaker during differentiation, regardless of the multiplication system, stimulated the multiplication of embryogenic tissue. The liquid medium used for the multiplication and differentiation of somatic embryos improved the synchronization of their development, which reached up to 95–99% depending on the system.