High Yield Isolation and Rapid Recovery of Protoplasts From Suspension Cultures of Tomato (Lycopersicon esculentum)

Summary Conditions were established which allow quantitative isolation of protoplasts during the growth cycle of suspension cultures of Lycoperskon esculentum . Protoplasts prepared from logarithmically dividing cell suspension (1–3 days) were small and plasma rich. When they were cultivated in liquid medium regeneration of cell walls started immediately and, within 40 h of cultivation, all living protoplasts, e. g. 60–70% of the plated protoplasts, had formed new cell walls. First mitoses could be detected after 18 h. Great mitotic activity was observed in the following days. Protoplasts derived from the phase of cell enlargement (4–7 days) were more heterogeneous in size and clearly vacuolated. Less than 10% of them regenerated cell walls and cell division occurred seldom. Pictures obtained by staining with Giemsa suggest that binucleate protoplast were formed from cells which were interrupted in mitosis during protoplast isolation.