© 1994 Heron Publishing—Victoria, Canada
Regulation of early flowering in Pinus banksiana
Robert A. Cecich (1), Hyun Kang (2) and Wladyslaw Chalupka (3)
1. North Central Forest Experiment Station, USDA-Forest Service, Columbia, Missouri 65211, USA / 2. North Central Forest Experiment Station, USDA-Forest Service, Madison, Wisconsin 53706, USA / 3. Polish Academy of Sciences, Institute of Dendrology, 62-035 Kornik, Poland / Received May 6, 1993
Summary
Seedlings of three families of jack pine (Pinus banksiana Lamb.) were subjected to 16 combinations of photoperiod, growth environment (outdoors, greenhouse and biotron) and gibberellin
(GA4/7) treatment. After 14 months, which included two dormancy induction periods, ovulate flowering was observed. There was a strong
positive correlation between flowering and seedling height; female flower production was stimulated by both a declining photoperiod
during bud development and GA4/7 treatment; and there was an interaction between GA4/7 treatment and family, such that the difference in flowering intensity between a late-flowering and an early-flowering family
was eliminated by GA4/7 treatment. The results suggest that the genetic control over the time of onset of flowering, and GA4/7-induction of flowering depend on a common mechanism.
Keywords:
gibberellin, photoperiod, seedling height.
