[Callus formation and its isoflavonoid accumulation in Maackia amurensis]

To obtain Maackia amurensis callus and investigate some factors influencing total isoflavonoid production in callus.

Different media were used for callus induction from cotyledonary and hypocotyl explants. Total isoflavonoid content was determined by UV spectrophotometer.

Medium types and hormone combinations influenced both callus formation and their developmental states. MS medium supplemented with NAA/BA or containing 2,4-D was suitable for callus induction from cotyledonary explants. Among the basal media tested, MS, N6 and B5 were suitable for cotyledonary callus formation and SH for hypocotyl callus formation. The formed callus could synthesize isoflavones. Media containing NAA were suitable for isoflavonoid production in cotyledonary callus and media containing 2,4-D/BA were suitable for hypocotyl callus, but 2,4-D/KT at high concentration inhibited the isoflavonoid accumulation in hypocotyl and coytledonary calli. According to the developmentally morphological characters, the formed callus could be classified into four types. II-type callus with yellow in color and friability in texture showed the highest accumulation of isoflavones.

The influences of medium type and hormone combinations on Maackia amurensis callus formation are reflected in both developmentally morphological characters and isoflavonoid accumulation of calli. Yellow, friable callus induced from cotyledonary and hypocotyl explants in MS or N6 medium supplemented with 2,4-D and BA exhibit the optimum growth and isoflavonoid production.