Micropropagation using a bioreactor system and subsequent acclimatization of grape rootstock ‘5BB’

• Five-liter airlift bioreactor was used to micropropagate grape seedlings.
• Inoculation density, air volume, and light intensity affected plantlet growth.
• All most of plantlets survived in vermiculite substrate.
• Leaf stomata recovered close function on the 16th day after transplantation.

To improve bioreactor culture systems for the micropropagation of grape rootstock ‘5BB,’ the effects of inoculation density, air volume, and light intensity on plantlet growth were investigated. Maximum plantlet growth and proliferation were observed when 65 nodes were inoculated in a 5 l balloon-type airlift bioreactor system, aerated with 150 ml min−1 air, and maintained under 50 μmol m−2 s−1 light intensity. During bioreactor culture, plantlet growth increased with increasing number of culture days, but no changes were observed between days 40 and 50; thus, 40 d was considered a suitable culture period. Electric conductivity and sucrose in the culture medium were negatively correlated with plantlet biomass. Several substrates were tested during acclimatization of the plantlets derived from the bioreactor, and vermiculite was observed to be the most advantageous substrate for transplantation. In this substrate, almost all of the plantlets survived and leaf stomata recovered their close function on the 16th day after transplantation.