CULTURING EMBRYOGENIC PROTOPLASTS OF HAMLIN SWEET ORANGE IN CALCIUM ALGINATE BEADS

Protoplasts were enzymatically isolated from log phase embryogenic swe et orange Citrus sinensis (L.) Osbeck cv. Hamlin! suspension cultures , embedded in 3-mm diameter Ca-alginate beads, and cultured in a growt h cabinet (15-20 mu mol m-2 s-1, 4-h photoperiod, 27-degrees-C). Plati ng efficiency exceeded 90% for Ca-alginate embedded protoplasts vs. 30 % for protoplasts cultured in a liquid medium. Embryoids formed from p rotoplasts were recovered after 20 days by dissolving the Ca-alginate matrix with a calcium sequestrant. Embryoids readily formed shoots tha t were rooted on MS + 0.01 muM NAA + 5% sucrose. Potential application s are discussed.