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In this study, the young leaves of Astragalus membranaceus （Fisch.） Bge. were sampledfor callus induction, and then three factors including culture base ingredients, elicitors andculture conditions were tested for their effects on callus growth, suspension cell culture, andsecondary metoblites contents, and culture parameters hereby were optimized for futureAstragalus membranaceus production. In addtion, changes of cellular morphology and severalbiophysico-chemical indexes during cell culture were also studied. The results are as follows:1.The most suitable culture base for callus induction was: MS+2,4-D(0.5mg·L-1)+6-BA(1.0mg·L-1)+NAA(2.0mg·L-1);24±1℃,darkness. And for callus proliferation,it was: MS+2,4-D(0.5mg·L-1)+6-BA(2.0mg·L-1);24±1℃, darkness. The callus growth periodwas about30～35d, and showed an “S”type.2.The most suitable culture base for polysaccharides accumulation in callus tissues was:MS+2,4-D(1.0mg·L-1)+6-BA(1.0mg·L-1)+NAA(1.0mg·L-1), containing80g·L-1sucrose,60mmol·L-1KNO3（non ammonium salt）,1.5mmol·L-1KH2PO4and1.496mmol·L-1CaCl2,24±1℃, illumination （1500～2000lx，12h·d-1）, UV irradiation for10min or30min in thelate stage of culture. For saponins accumulation was:6,7-V+2,4-D(2.0mg·L-1)+6-BA(2.0mg·L-1)+NAA(1.0mg·L-1), containing100g·L-1sucrose, a1:1ratio of NH+to NO3-(nitrogenconcentration was60mmol·L-1),1.5mmol·L-1KH2PO4and8.97mmol·L-1CaCl2,24±1℃，illumination；The potency order influencing total saponins accumulation was:2,4-D>6-BA>NAA. The most suitable culture base for flavonoids was: MS+2,4-D(0.5mg·L-1)+6-BA(1.0mg·L-1), containing80g·L-1sucrose, the ratio of NH4+to NO3-was1∶2(nitrogenconcentration was60mmol·L-1),1.5mmol·L-1KH2PO4,1.496mmol·L-1CaCl2,24±1℃,darkness; in terms of their potency enhancing total flavonoids accumulation, the order was:NAA>6-BA>2,4-D. Treated by ultraviolet （UV） radiation for30minutes in the late stage ofcallus culture, it could facilitate the accumulation of favonoids and increase the PLA activity.3. Correlation exists between cellular morphology and secondary metabolism duringcallus culture. Generally, cells elongation facilitated the synthesis of secondary metabolites in callus. Similarly, the effect of growth regulators on secondary metabolism was also associatedwith the mitotic index to some extent.4. It was demonstrated that6,7-V+2,4-D0.2mg·L-1(containing40g·L-1sucrose,5.98mmol·L-1Ca2+,0.1mmol·L-1ferric salt,0.555mmol·L-1inositol,1.249mmol·L-1KH2PO4)favored for the growth of Astragalus suspension cells; culture parameters were: rotation speed140rpm,22士1℃and darkness;and the cell growth period was14-day long.5. On the basis of above experiments,6,7-V was employed as the culture medium forproducing polysaccharides, saponin and flavonoid from astragalus suspension cells. Forpolysaccharide accumulation, it was necessary to add3.0mg·L-1NAA into6,7-V medium,together with30g·L-1maltose,0.555mmol·L-1inositol and1.249mmol·L-1KH2PO4; forsaponin accumulation, it needed to add0.5mg·L-12,4-D, together with40g·L-1maltose,0.555mmol·L-1inositol, and1.249mmol·L-1KH2PO4, and furthermore, adding of elicitors,i.e., salicylic acid1μmol·L-1, oxalic acid and hydrogen peroxide100μmol·L-1, was effectiveto promote the accumulation of saponin; like the two above secondary metabolites, adding1.0mg·L-12,4-D with30g·L-1maltose,0.555mmol·L-1inositol and1.249mmol·L-1KH2PO4wasalso necessary for flavonoid production.
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