Plant Regeneration from Protoplasts Derived from Suspension Cultures in Leymus racemosus

Calli initiated from mature embryos of Leymus racemosus (Lam. Tzvel. =L. giganteus were transferred onto the AA and DM media to produce friable embryogenic callus,from which embryogenic suspension cultures were established. Protoplasts were isolated from the embryogenic suspension cultures and were cultured either in thin-layer liquid medium or in double-layer (agar/liquid) medium. When visible calli were formed they were transferred onto the NBI agar medium or into the MBL liquid medium for further proliferation. These calli were transferred onto differentiation media of NBII and NR, where green spots were developed. Plants with both shoots and roots can be recovered from these green spots on MS Ⅱ medium containing 0.5 mg/L NAA. The results showed that the Km8p basal medium was favourable to the culture of L. racemosus protoplasts during the early stages of culture. In addition, the composition of the media added to the cultures had a marked influence on the growth of protoplasts, indicating that the nutritional requirements in this plant were different at various stages of protoplast growth and differentiation.