Advances in blackberry synthetic seeds production

Recently, there has been a notable increase in both cultivation and consumption of blackberries, accompanied by a rising demand for high-quality nursery materials. Traditionally, blackberry plants have been propagated through agamic methods, primarily involving layering and cutting. However, these methods come with constraints such as the requirement for extensive planting area, and labor-intensive processes. As a solution to these limitations, in vitro propagation, specifically micropropagation, has been successfully proposed and widely adopted. Within this context, encapsulation aiming to produce synthetic seeds emerges as a strategy to enhance the productivity of in vitro propagation and facilitate the exchange of plant material between laboratories. Although synthetic seeds have shown applicative potential for various plant species, research on protocols for the production and utilization of encapsulated propagules in blackberry is still in its early stages. This study focuses on evaluating the impact of low-temperature conservation (4 °C) for 120 days and the type of in vitro sowing media (agarised, perlite, and potting substrates) on the performance of synthetic seeds of the blackberry cultivar Thornfree. The synthetic seeds were obtained through the encapsulation of the base of vitro-derived clumps. Results obtained using an agarised sowing substrate indicate that storing blackberry synthetic seeds at low temperatures has no adverse effects on their viability, regrowth, conversion, number of shoots, and rooting percentage. Moreover, certain parameters, such as the number and length of roots, shoot length, and fresh weight of plantlets, were found to be higher in the stored synthetic seeds compared to the unconserved seeds. The type of sowing substrate significantly influences the performance of synthetic seeds, with satisfactory conversion rates and plantlet development observed only in the agarised substrate.