Produzione di semi sintetici e conservazione di un portinnesto di vite (Kober 5BB)

Synthetic seed technology has been recently applied to in vitro grown plant explants, such as shoot tips and nodal segments. It is one of the most important and advance applications of in vitro culture. Moreover, synthetic seeds are utilised for innovative cryopreservation procedures, such as encapsulation-dehydration and encapsulation-vitrification, to preserve for long-term germplasm. This study was aimed to the development and application of the synthetic seeds technique in micropropagation, carrying out a protocol for encapsulation and storage of the rootstock Kober 5BB. In vitro grown Kober 5BB explants, shoot tips and nodal segments, were encapsulated into an “artificial endosperm”. Different sucrose concentrations (0, 10, 30 e 60 g l-1) were added in alginate beads, to evaluate its effects on germination. For germination the synthetic seeds were maintained on semi-solid MS medium, at 23°C with 16 h of photoperiod. ‘Germination’ percentage and ‘germination’ time were recorded. To evaluate in vitro conservation of encapsulated explants of the grape rootstock, synthetic seeds with shoot tips and nodal segments were kept at 4°C under light and dark conditions, for 3, 6 and 9 months. ‘Germination’ percentage was evaluated at the end of each storage period, after transferring in a proliferation substrate (MS medium, added with 5 ¼M BA) under standard growth conditions.