Selection of high pyrethrin producing tissue cultures.

Axenic callus and shoot cultures of pyrethrum have been shown to be capable of pyrethrin biosynthesis. The influence of explant source on the biosynthetic capacity in cultured tissue was examined. Explants of various plant organs were taken from high and low yielding plant selections. The conditions necessary for the establishment of these explants in culture are described. Analytical screening of the tissue lines enabled the selection of a few "high yielding" strains which were derived from high yielding plant selections. Differentiated cultures tended to produce more pyrethrins than did callus cultures.