Abstract: Stem segments of Dend robium huoshanese were used to induce p rotocorm-like bodies ( PLBs) and the development of PLB s was studied. The results showed that the most suitable medium for PLBs inducing is Knudson + 2, 4-D 0.1 mg·L ^{- 1} + KT 0.05 mg·L ^{- 1} , the induction ratio can reach 25.50% on
thismedium. Culture methods also affect the proliferation of PLB s, shaking-bottle liquid cultivation is more suitable for PLB s proliferation among the four culture methods, such as solid culture, double layer, static liquid and haking-bottle liquid. Anatomical investigation revealed that the formation of PLB s from Dendrobium huoshanese is similar to zygotic embryo, development from proem-bryo, globularem-byro, heart-shaped embryo,torpedo-embryo, then from cotyledon to mature embryoid. The development of PLBs can be divided into five stages: Formation of PLBs, hypertrophy of PLB s, differentiation of stalks and leaves, formation of stalks and leaves, stretch of stalks and leaves.

Key words: Dendrobium huoshanese, protocormlike bodies, embryoid, formation and development