Temporary Immersion for Plant Tissue Culture

Abstract

Mass propagation of plants by tissue culture is labour-intensive and costly. Gelling agents have many drawbacks: they are not an inert medium component and do not enable easy automation. So liquid culture systems, provided that hyperhydricity is eliminated, are considered to be far better: culture conditions are much more uniform, media can be changed easily, sterilisation via ultrafiltration is possible and vessel cleaning after the culture period is greatly simplified. Bioreactors previously developed are not suitable as they are mainly adapted to bacterial culture and do not take into account the specific requirements of plant cells, such as sensitivity to shear forces, mechanical damages or foam formation in bubble aerated bioreactors. New systems have to be developed which must

• avoid continuous immersion which adversely affects growth and morphogenesis

• provide adequate oxygen transfer, sufficient mixing and limit shear levels

• enable sequential medium changes and automation

• reduce the risk of contamination

• be as cheap as possible