Effects of Pluronic F-68 on growth of transformed roots ofSolanum dulcamara

Summary The effects of the non-ionic surfactant, Pluronic F-68, on the growth of transformed roots ofSolanum dulcamara L. have been studied. Growth was stimulated by addition of low concentrations (0.001–0.1% w/v) of freshly-prepared commercial grade Pluronic to liquid culture medium, with maximum increases in root fresh and dry weights at 0.01% (w/v). In contrast, higher concentrations (0.25–1.00% w/v) of freshly-prepared Pluronic inhibited growth. Freshly-prepared purified Pluronic retarded root growth, even at concentrations that were stimulatory with the commercial preparation. Similarly, commercial grade Pluronic solutions stored at 4°C or 22°C for 5 days (aged) were inhibitory to root growth.