OBJECTIVETo study the effect of plant growth regulator mepiquat chloride (DPC) on the growing development of plant and the content of active compounds in Scutellaria baicalensis.

METHODAfter spraying DPC during the seedling period, the length of taproot, fresh weight of root, diameter of taproot and the length of stem were measured. The contents of baicalin, baicalein and wogonin were determined by HPLC, respectively. Total flavonoids and scavenging DPPH were determined with ultraviolet spectrophotometry.

RESULTAfter spraying DPC, fresh weight of S. baicalensis root was significant increased, and root diameter was also increased. The contents of baicalin and total flavonoids were significantly increased and baicalein and wogonin were decreased remarkably. Compared with controls, scavenging activity of ethanol extracts on DPPH free radical was no significant changed after spraying DPC.

CONCLUSIONPlant growth regulator DPC could regulate the growth on the ground and underground effectively, and could enhance the content of flavonoids compounds of S. baicalensis.