STRATEGIES FOR PROMOTING DIVISION OF CULTURED PLANT-PROTOPLASTS - BENEFICIAL-EFFECTS OF OXYGENATED PERFLUOROCARBON

Assessments have been made of physical and chemical options, alone and in combination, for gaseous manipulation of cassava (Manihot esculent a Crantz.) leaf protoplast cultures. Protoplasts were cultured for 25 d in liquid medium at an initial plating density of 4 x 10(5) ml(-1) o verlying (1) agar-solidified medium (control), (2) agar medium under a n oxygen-enriched (10 mbar, 1 min) atmosphere, (3) agar medium supplem ented with perfluorodecalin (Flutec(R) PP5), or (4) agar medium supple mented with oxygenated (10 mbar, 15 min) perfluorodecalin. Similar exp erimental treatments were also set up, with glass rods embedded in the agar medium. The mean initial plating efficiency (IPE) of protoplasts following culture with oxygenated perfluorodecalin without glass rods (6.7 +/- 0.6%; n = 3) was over 2-fold greater (P < 0.05) than that of control cultures (2.6 +/- 0.2%; n = 3). The mean IPE of protoplasts c ultured with oxygenated perfluorodecalin in the presence of glass rods (5.8 +/- 0.2%; n = 3) was also over 2-fold greater (P < 0.05) than co ntrols. There was no significant difference between the IPE of protopl asts cultured under an increased oxygen atmosphere or with oxygenated perfluorodecalin, irrespective of the presence of glass rods.