Development and evaluation of a synthetic seed system for cassava propagation.

Abstract

Cassava is a crop of major global importance for food security; however, its conventional vegetative propagation through stem cuttings is constrained by low multiplication rates and significant phytosanitary risks. In this study, we evaluated a synthetic seed system and examined how the physicofunctional properties of sodium alginate matrices (0.8-6%) influence the ex vitro morphogenesis of axillary buds. We investigated the relationship between matrix properties and bud emergence using two distinct crosslinking agents, CaCl2 and Ca(OH)2. CaCl2 induced rapid gelation through the egg-box mechanism, generating densely crosslinked polymer networks with low water solubility (41-55%). These matrices may have imposed greater physical constraints on bud development reducing shoot emergence to 11.1% at low polymer concentrations and completely suppressing emergence at concentrations ≥4%. In contrast, Ca(OH)2 produced encapsulation matrices that supported up to 80.6% emergence, enhanced vegetative vigor, and greater biomass accumulation. Although the best encapsulated treatments showed high emergence, they did not surpass the non-encapsulated control (91.7%). Overall, sodium alginate concentrations of 0.8-1.0% provided the most favorable balance between matrix integrity and bud emergence. The results suggest that differences in matrix structural properties may influence synthetic seed performance; however, parameters such as porosity, permeability, oxygen availability, and hydration dynamics were not directly measured. These findings provide a foundation for further research on cassava synthetic seed technology. Additional studies evaluating storage longevity, transport, and field establishment are required before practical application.