Identification and assay of pyrethrins in Chrysanthemum cinerariefolium calli

Summary Callus from four clones of Chrysanthemum cinerariaefolium have been investigated for pyrethrins biosynthesis. Calli from disc-flowers, bud-flowers, stems and leaves of clone HY D were cultivated. Best growth was obtained by initiating the culture on Murashige and Skoog medium containing 3% sucrose, 1% agar, 4 ppm -naphtoxy acetic acid (ANA) and 0.4 ppm 6- benzyl aminopurine (BAP) for 28 d, then transfering explants on i.e. at the beginning of the stationnary phase. Disc-flowers calli from two high-producers clones (HY C and HY D) and two low-producers clones (SY A and SY B) were also cultivated. Pyrethrin amounts found in callus cells showed a direct relationship between parental clone synthesis ability and callus cell production. Selection of high-producers clones is thus essential for optimisation of pyrethrin synthesis.