Electrostatic encapsulation and growth of plant cell cultures in alginate

The growth of callus tissue from African Violets, encapsulated in alginate using electrostatics, was investigated as well as the mechanism of alginate droplet formation. Alginate microbeads as small as 500 (+/-50) microns in diameter could be produced by electrostatic extrusion directly from a plast ic syringe (1900 micron extrusion orifice), in the absence of a needle. Vid eo analysis of the mechanism of electrostatic alginate droplet formation fr om the syringe showed the development of a Taylor cone-like droplet which e xtended to form a thin strand that then broke up into droplets. Autoclaving of the alginate/medium solution significantly reduced its viscosity, givin g smaller beads. Calculated microbead diameters agreed well with experiment al values. Callus tissue from leaf explants was successfully immobilized an d cultured using electrostatic extrusion. Tissue immobilized using 4% algin ate in medium and cultured on agar grew best, producing a complete plantlet within four months. The long-term aim is to develop an effective method fo r large production of artificial seeds.