EFFECTS OF PLURONIC F-68 ON GROWTH OF TRANSFORMED ROOTS OF SOLANUM-DULCAMARA

The effects of the non-ionic surfactant, Pluronic F-68, on the growth of transformed roots of Solanum 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-degrees-C or 22-degrees-C for 5 days ("aged") were inhibitory to root growth.