Optimization of the conditions for production of synthetic seeds by encapsulation of axillary buds derived from minituber sprouts in potato (Solanum tuberosum)

Synthetic seed technology is a convenient alternative to conventional multiplication in potato. In this work, we studied and optimized the process of alginate encapsulation of axillary buds derived from potato minituber sprouts (PMSs). We assayed different concentrations of sodium alginate, CaCl2 and matrix culture media, different explant sizes, different concentrations of 24-epibrassinolide (EBr) applied at different stages of the encapsulation process, different planting substrates and different cold storage periods in order to determine the best conditions for encapsulation in cvs. Sante and Agria. The conditions that resulted in the greatest regrowth rates and speed in both cultivars involved the choice of 2-3 mm-long buds, a 2 days pre-culture of buds in culture medium supplemented with 10(-6) M EBr, encapsulation in 3 % sodium alginate with 1 % CaCl2 and full-strength MS culture medium, regrowth in solid MS culture medium and then transfer to coco peat (coir fiber pith) for conversion into plantlets. We also found that buds encapsulated under these conditions maintained the initial viability rates for up to 120 days in 'Sante' and 90 days in 'Agria', although regrowth speed decreased after 60 days in both cultivars. We demonstrate the possibility of producing synthetic seeds efficiently using axillary buds derived from PMSs.