Gibberellin A20 content of Bryophyllum daigremontianum under different photoperiodic conditions as determined by gas-liquid chromatography

Summary The gibberellin A₂₀ content of the long-short-day plant Bryophyllum daigremontianum (R. Hamet and Perr.) Berg. under different photoperiodic conditions was determined by gas-liquid chromatography. Purified extracts from ten plants were adequate for quantitative analysis by this method. The level of GA₂₀ increased following transfer from long-day (LD) to short-day (SD) conditions until after 38 SD it was three times higher on a dry weight basis than in comparable plants under continuous LD. No GA₂₀ could be detected in extracts of plants under permanent SD. These results are in agreement with earlier data obtained by assaying Bryophyllum extracts with the d-5 mutant of corn.