STUDOES ON RAPID PROPAGATION AND ORIGAN GENESISTION OF ATRACTYLODES MACROCEPHALA FROM STEM SEGMENT

Proliferation increased with unpinehed shoot tip, placed horizontally on modified medium containing 5μm 6-benzylaminopurine （6-BA） 0.1μm Naphthaleneacetic acid （NAA） and 0.5—1.0μm Gibberellic acid（GA₃）, The incremental times of bud was as high as 7.7. The addition of GA₃ stimuted bud differentiation and elongation in the concentration ranging from 0.5—1.0mg/L, Cytohistologic examination showed that callus originated from mainly parenchyma cells of pith. The meristematic nodules originated from deep within calli and might be progressively differentiated later into hestshaped vascular nodules with tracheids in the inner surrounded by cambiumlike cells. There were three forms of bud formation. First, by germination of auxiliary bud. Second, the buds developed from both superficial meristemoids and the meristematic regions deep within calli. Third, somatic embryogenesis or adventition buds produced from meristemoids deep within the abnormal embroids. The stem of shoot was cut, then the excised stem was transferred on to the medium of 1/2MS+NAA 0.5mg/L for rooting. The adventitions roots emerged from the stem were endogenesis in origin. Using the technique to obtain whole plantlet by tissue culture provides an effect method for rapid propagation.