HEMOGLOBIN-ENHANCED MITOTIC DIVISION IN CULTURED PROTOPLASTS

Protoplasts from cell suspensions of albino Petunia hybrida cv. Comanc he were cultured for 9 days in nutrient medium containing Erythrogen(T M), a purified bovine haemoglobin solution (supplied at 10% w/v) at 1: 50 - 1:500 (v/v). In some assessments, the non-ionic surfactant Pluron ic(R) F-68 (Poloxamer 188), was also added to the culture medium at 0. 01-1.0% (w/v). Erythrogen(TM) at 1:50 (v/v) increased the mean initial protoplast plating efficiency (IPE; 18.5 +/- 0.8%, n = 5 throughout) by 64% (P < 0.001) above that of controls (11.3 +/- 0.4%). Supplementa tion of medium with 1:50 (v:v) Erythrogen(TM) and 0.01% (w/v) Pluronic (TM) F-68, increased the mean IPE (24.4 +/- 1.4%) by 92% (P < 0.001) o ver control (12.7 +/- 1.1%). Similar results were obtained for mesophy ll protoplasts of Passiflora suberosa, with 1:50 and 1:100 (v/v) Eryth rogen(TM) increasing the mean IPEs to 87% and 93% respectively, over c ontrols. This beneficial and synergistic effect of Erythrogen(TM) with Pluronic(R) F-68, on mitotic division of cultured Petunia and Passifl ora protoplasts, should also facilitate the culture of isolated protop lasts and cells of other, agronomically-important, species.