Use of an ultrasound cell retention system for the size fractionation of somatic embryos of woody species

Abstract

 The potential of ultrasonic standing waves for trapping suspended particles was utilized successfully for differential size fractionation of plant somatic embryos. In a flow-through resonator equipped with a 200-kHz piezoceramic transducer, embryos of different sizes corresponding to different developmental stages could be retained by varying the electric power input and flow speed. The system was initially established for carrot (Daucus carota) somatic embryos and subsequently adapted for the larger-sized embryos of the woody species cork oak (Quercus suber), grapevine (Vitis Berlandieri × rupestris) and cherry (Prunus incisa × serrula). Separation performance was confirmed by analysing the different fractions for the expression of homeobox genes which are differentially expressed during embryogenesis. No inhibitory effects of embryos on short- and long-term development could be observed.