Plant regeneration from embryogenic cell suspension-derived protoplasts ofrubber

Embryogenic cell suspensions of rubber derived from immature inflorescences and inner integuments of immature fruits released 3.1 +/- 0.2 x 10(7) prot oplasts g(-1) f. wt. (mean +/- s.e.m, n = 10) and 3.2 +/- 0.2 x 10(7) proto plasts g(-)1 f. wt., with mean viabilities of 83 +/- 2% and 77 +/- 8%, resp ectively. Sustained mitotic division was observed only when protoplasts wer e cultured in KPR liquid medium on nitrocellulose membranes overlying the s ame semi-solid medium containing Lolium multiflorum nurse cells. Protoplast -derived cell colonies were produced within 2 months of culture. Protoplast -derived cell colonies proliferated, upon subculture to MS-based regenerati on medium, with 40% of the protoplast-derived calli developing somatic embr yos. The latter germinated into plants on the same medium after 3 months of culture.