Influence of benzyladenine on condensed tannin formation and callus growth in cultures from sainfoin (Onobrychis viccifolia Scop.) cotyledons.

Cotyledons from aseptically grown seedlings of sainfoin (Onobrychis viciifolia Scop.) were used as explant material to grow callus tissue for periods of 21 and 31 days. The formation of cells containing condensed tannins was induced by adding a range of BAP concentrations to an mB5 culture medium containing 2,4-D. After 21 days the fresh weight of calli treated with BAP was much greater than the control and appeared highest at the 0.6 mg/L level. Fresh weight was reduced at high BAP levels (2 to 8 mg/L) but still remained well above the control. The formation of tannin-filled cells was genotype-specific but occurred in all treatments with BAP. After 21 days in culture, fresh weight and tannin formation increased with the BAP level at the lower BAP concentrations. After 31 days, the growth rate slowed in the control and the lower BAP concentration, but continued at a high rate in the remaining treatments; the number of tannin-filled cells appeared to decline. The results show that in sainfoin callus culture, BAP induces the formation of condensed tannin, a secondary metabolite, and concomitantly produces a high growth rate.