Plant regeneration from protoplasts of indica rice: genotypic differences in culture response.

Fourteen varieties of indica rice (Oryza saliva L.) were examined for their capacity for plant regeneration from protoplasts using the nurse culture methods developed for japonica rice. Calli induced from germinating seeds were grouped into two types: type I, white and compact; type II, yellow and friable. In four varieties producing type II callus, colony formation (2%-4.5%) and plant regeneration (2%-35%) were observed. The inability to develop suspension cultures was a major obstacle in regenerating plants from protoplasts of the remaining rice varieties studied.