短日植物たるアサガオの日長反応

抄録

1) The critical dark period of Japanese morning glory was found to be ca. 8-9 hours.
2) A plant with a single leaf can be induced to initiate flower primordia by the application of a single dark period of 16 hours' duration.
3) If the induction is strong enough, the growing point of the shoot is consumed in initiating a terminal flower bud.
4) The number of plants with flowers or terminal flower primordia and the number of flowers initiated can be used in ascertaining quantitative relations in investigations of photoperiodic responses.