Flower morphogenesis in Rosa hybrida 'Mercedes' as studied by cryo-scanning electon and light microscopy. Effects of light and shoot position on a branch

Flower bud development in Rosa hybrida cv. ' Mercedes' was studied in shoots grown at different irradiances and sprouting from axillary buds at different branch positions. Cryo-scanning electron microscopy and light microscopy were used to visualize, characterize and determine flower morph...

Full description

Saved in:
Bibliographic Details
Published in:Annals of botany 1995, Vol.75 (2), p.199-205
Main Authors: Maas, F.M, Hofman-Eijer, L.B, Hulsteijn, K
Format: Article
Language:English
Subjects:
branches
buds
developmental stages
flowers
light
light relations
morphogenesis
Rosa
shoots
ultrastructure
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Flower bud development in Rosa hybrida cv. ' Mercedes' was studied in shoots grown at different irradiances and sprouting from axillary buds at different branch positions. Cryo-scanning electron microscopy and light microscopy were used to visualize, characterize and determine flower morphogenesis during early shoot development. Up to the moment of visible flower bud appearance on the plant, flower morphogenesis was divided into nine stages. This classification was based on external and internal charactenstics of the primordium. All shoots of the rose 'Mercedes', whether positioned uppermost or second on a branch and whether grown at 300 or 150 micromol m-2 S-1 PAR (12 h d-1) developed equally up to flower stage 7, i.e. the stage just before visible initiation of stamen and pistils. Signs of flower bud abortion were the compactness of the flower bud at developmental stage 7 (height/width < 1.5) and the sprouting of axillary buds positioned just below the flower bud primordium. It was concluded that once a flower bud has reached a height to width ratio larger than 1.5, and once stamen and pistil development has started, it has passed the critical developmental stage in which abortion may occur. Flower developmental stage was closely related to shoot length. This relationship was not affected by irradiance level nor by shoot position on a branch. Therefore, cultivation treatments aimed to improve flower production by reducing flower abortion, such as supplementary lighting, will be most effective when applied during the first 2 weeks of shoot growth in which the flower develops up to stage 7.
ISSN:0305-7364
1095-8290