biologia plantarum

Biologia plantarum 43:511-515, 2000 | DOI: 10.1023/A:1002894019412

Effect of Photoperiod and Nitrogen Supply on Basal Shoots Development in Rhododendron Catawbiense

J. Fustec^1,*, F. Beaujard²

¹ Facultédes Sciences, UMR SAGAH, Angers Cedex, France e-mail

² INRA, UMR SAGAH, BeaucouzéCedex, France

In order to control young plant form by modifying culture conditions, plants of Rhododendron catawbiense from in vitro culture were grown in a greenhouse under different photoperiodic treatments (long or short days) combined or not with a several-week nitrogen starvation. After 12 weeks of culture under long days (16 h) with nitrogen supply, plants showed a rhythmic acrotonous development. When long days were combined with a six-week nitrogen starvation, the apical growth pause was extended leading to an increase of the number of acrotonous lateral ramifications. Short-day (8 h) treatment affected distal burst potential and moreover when a concomitant nitrogen starvation was applied. This lack of distal development allowed basal buds swelling, leading to basitonous plants. When plants were returned back to long days after 2, 4 or 6 weeks under short days, distal buds resumption competed with basal shoots development. Durable basitonous plants were obtained by a 12-week short days treatment combined with a 6-week nitrogen starvation.

Keywords: day length; morphogenesis; nitrogen starvation; woody plant

Subjects: morphogenesis, nitrogen starvation, photoperiod; nitrogen supply, photoperiod, shoot development; photoperiod, nitrogen starvation, shoot development; Rhododendron catawbiense

Published: December 1, 2000  Show citation