The Effects of Growth Regulators on Development of Nicotiana affinis Flowers In Vitro

Excised flower buds of Nicotiana affinis were grown to maturity in media in which growth regulators were added to evaluate their effects on growth and development. As the concentration of naphthaleneacetic acid (NAA) was increased from 10-7 to 10-4 m, the number of days required for the buds to open decreased, and the number of days required for the corolla tubes to turn brown increased. Indoleacetic acid (IAA) and indolebutyric acid (IBA) did not affect the rate of bud opening. As the concentration of IBA was increased, however, the days required for the corolla tubes to turn brown increased, but not as much as for buds in media with NAA. IAA had no effect on browning of corolla tubes. At high concentrations of NAA and kinetin the corolla tubes were shortened. Kinetin did not affect the rate of bud opening or days till the corolla tubes turned brown.