EFFECTS OF GROWTH SUBSTANCES ON EXCISED FLORAL BUDS OF AQUILEGIA

Buds at various stages of development were grown for 3 weeks on solid media containing coconut milk, minerals, vitamins, sucrose, and varying quantities of gibberellic acid, indoleacetic acid, and kinetin. The best average growth was obtained on media containing GA at 2.0 mg/liter, IAA at 1.0 mg/liter, and kinetin at 0.05 mg/liter. When results were compared for buds explanted at very young stages and at older stages, however, young buds attained better average growth on media with 0.5 mg/liter of IAA. Evidence is presented for interaction between IAA and kinetin. With buds explanted at young stages, as the kinetin concentration was increased, optimum growth occurred on media with increasing concentrations of IAA. With older buds, on the other hand, as the kinetin concentration was increased, optimum growth occurred on decreasing concentrations of IAA. Bud growth was compared on media with growth substances sterilized by autoclaving with growth on similar media with these substances filter-sterilized. Better growth occurred generally on the media with filter-sterilized ingredients. A long-range objective of this research is the development of a system that would make possible quantitative measurements of floral development in vitro.