An inhibitor of auxin polar transport, 2,3,5-triiodobenzoic acid (TIBA), stimulates shoot growth and flowering of partially cooled tulip bulbs.

摘要

Tulip bulbs (Tulipa gesneriana 'Apeldoorn' and 'Gudoshnik') with a terminal bud containing a complete flower were treated with 2,3,5-triiodobenzoic acid (TIBA) at 0.2 and 0.5% (w/w in lanolin) on the scale around the basal plate of bulbs and then subjected to the cooled treatment. After different periods of dry-cooling at 5 degrees C, bulbs were grown in a greenhouse under natural light conditions. The application of TIBA to the partially dry-cooled bulbs substantially promoted not only shoot growth but also flowering. The growth- and flowering-promoting effect of TIBA was weaker in the fully cooled than in the partially cooled bulbs. It should be mentioned that TIBA applied to the scale did not stimulate shoot growth and flowering in uncooled tulip bulbs. These results suggest that the application of TIBA to the scale of tulip bulbs partially replaces the cold treatment, or shortens the period of dry-cooled treatment for shoot growth and flowing in tulips bulbs. A possible explanation for TIBA-induced shoot growth and flowering in partially cooled tulip bulbs is proposed on the focus of the balance of endogenous plant hormones.