Selection of penstemide and serrulatoloside producing clones in penstemon serrulatus by small-aggregate cloning

A plating method is described for cultured cells of Penstemon serrulatus Menz. which allows effective cloning of aggregates consisting of less than 10 cells, on a simple synthetic medium. The obtained clones snowed high diversity with respect to their ability to produce penstemide, an ester iridoid of the Valeriana-type. Some of the clones produced higher quantities of this compound than the original cell line. The content of another iridoid glucoside of the same type, serrulatoloside, was also determined.Abbreviations SH Schenk and Hildebrandt (1972) - IBA indole-3-butyric acid - BAP 6-benzylaminopurine - PE plating efficiency - d.w. dry weight - sd standard deviation