Rapid mass propagation of Chrysanthemum cinerariaefolium Vis. by callus culture and ability to synthesise pyrethrins

Rapid mass propagation of Chrysanthemum cinerariaefolium from young flower heads was developed to compare the ability of callus, in vitro shoots and r ooted plants, and original plants to synthesize pyrethrins. The ability to synthesise all six pyrethrin components increased with differentiation. Jas molin II and cinerin II were the main products present in mother plant shoo ts, whereas pyrethrin I was the greater component present in callus and in vitro plants. Clonal propagation increased the pyrethrin I content compared to that of plant shoots and young flowers. Total pyrethrin content was the same in in vitro and plant shoots, but lower in these shoots than in young flowers. The pyrethrin I/pyrethrin II ratio, which is directly related to insecticidal activity, varied from 3.4 in in vitro shoots to 0.87 in mother plant shoots and young flowers.