Effect of Photoperiodic Manipulation on Seasonal Variation in Bud and Shoot Regeneration of Rieger Begonia Leaf Cuttings1

Abstract

Abstract Leaf cuttings of ‘Schwabenland Red’ Rieger begonia (Begonia × hiemalis Fotsch) regenerated buds prolifically, whereas ‘Aphrodite Pink’ regenerated buds sparingly, with fewer buds per cutting. Bud initiation was maximal in winter in both cultivars. Shoot development was maximal in ‘Schwabenland Red’ in spring and fall, and was maximal in ‘Aphrodite Pink’ in winter. Lack of bud initiation inhibited shoot development in ‘Aphrodite Pink’ but not in ‘Schwabenland Red’. Seasonal variation was eliminated, and shoot development was maximized in ‘Schwabenland Red’ when mother plants were grown on a short day and cuttings on a long day cycle. This daylength procedure did not eliminate seasonal variation in ‘Aphrodite Pink’, although it maximized shoot development over the year. Factors other than photoperiod may have played a role in ‘Aphrodite Pink’.