The development of leaves and axillary flowers along the primary shoot axis of Cyclamen persicum 'F-1 Rosemunde' (Primulaceae)

• Published in: Botanical gazette (Chicago, Ill.) Ill.), 1981-06, Vol.142 (2), p.214-221
• Main Author: Sundberg, Marshall D.
• Format: Article
• Language: English
• Subjects: Flower buds; Flowering; Flowers; Growing seasons; Leaves; Peduncle; Petioles; Plant growth; Planting seasons; Plants
• ISSN: 0006-8071; 1940-1205
• DOI: 10.1086/337216

Leaf emergence in Cyclamen persicum 'F-1 Rosemunde' followed a sigmoid pattern which was linear between 12 and 33 wk after planting. The early elongation of leaf laminae and petioles was exponential. The rates of lamina and petiole elongation along the axis exhibited heteroblastic patterns, but maxima occurred in different leaves. A shift in allometry constants (leaf lamina vs. petiole) from < 1 to > 1 occurred at leaves 6 and 7. Flowers were initiated at the same rate as leaves. Elongation of flower buds and peduncles was exponential until just prior to anthesis. The rates of bud elongation in the first 20 flowers were essentially constant, but the rate of peduncle elongation decreased at successive nodes. The maximum rate of lamina elongation at leaf 6, as well as the shift in allometry at leaves 6 and 7, may be associated with floral induction. Although the subtending leaf had an important role in the initiation of floral primordia, its importance in later floral development may be minimal. Use of the plastochron index is proposed in studying both leaf and flower development during the 12-23 wk after planting.