LEAF BISECTION FOR THE ENZYMATIC ISOLATION OF MESOPHYLL PROTOPLASTS FROM SAINTPAULIA-IONANTHA

We describe a rapid and efficient procedure for isolating leaf mesophy ll protoplasts from Saintpaulia ionantha (African violet). Because of the unusual surface properties of the leaf, efficient digestion requir ed bisection of the lamina into abaxial and adaxial halves to expose t he mesophyll. Enzymatic digestion occurred during a 3 h incubation wit h 2 % (m/v) driselase in 0.50 M mannitol, yielding 2 - 3 x 10(5) proto plasts g(-1) (f.m.), with 70 % viability. Protoplasts ranged in size f rom 50 to 100 mu m, and were derived from mostly non-photosynthetic me sophyll parenchyma.