Temporary Immersion System as an Innovative Approach for In Vitro Propagation of Sorbus domestica L.

The genus Sorbus has maintained an extremely relevant role over time from a landscape and environmental perspective in many countries in the Mediterranean and Central Europe. Based on the requirements coming from the environmental policies provided in the European strategy Next Generation EU, Sorbus has been considered a valuable species to be introduced in urban and peri-urban areas. The purpose of this study was to propagate four Sorbus accessions selected in the Sicilian territory, Southern Italy, using the liquid substrate in temporary immersion bioreactors Plantform (TM). The results obtained showed that the presence of 1 mg L-1 mT in the substrate in combination with IBA 0.05 mg L-1 produced a significant number of shoots (4.7) and a greater length (2.2 cm). Among the accessions, there were statistically significant differences; the accession SN2 and SN1 produced more shoots (respectively, 4.0 and 3.6), and a greater length of the shoots was observed in the selections SN4 and SN3 (respectively, 2.4 cm and 2.3 cm). The relative growth rate (RGR) was significantly influenced by the presence of the culture substrate of the combination of cytokines and auxin; SN4 selection showed the best RGR results of 8.3 mg(-1) d(-1). The use of the bioreactor Plantform (TM) in Sorbus domestica L. has favored a better development of plants obtained in vitro, demonstrating that this system is a valid alternative for the micropropagation of Sorbus.