Efficient plant regeneration from Indica (group 1) rice protoplasts of one advanced breeding line and three varieties.

Regenerable embryogenic suspensions were established from one Indica (group 1) rice advanced breeding line and 9 Indica (group 1) rice varieties in 6-8 weeks. Four were chosen for protoplast culture and plant regeneration. About 4-7×10(7) protoplasts were isolated from one gram of 8-week-old cell suspension. High plating efficiency (30.5%) and colony formation (13.7%) were obtained using nurse culture methods. A high plant regeneration frequency (67.5%) was observed for line IR57311-95-2-3. In total, 322 plants were regenerated. All the regenerated plants were fertile.