On the Genetics of the 'Bud-Flowering' Trait in the Ornamental Crop Calluna vulgaris

摘要

The ornamental crop Calluna vulgaris is of increasing importance to the horticultural industry due to a flower organ mutation, the so-called 'bud-flowering' phenotype, in which buds remain closed throughout the total flowering period and thereby maintain more colourful flowers for a longer period of time than the wild-type. Moreover, stamens are missing. In order to clarify the genetics of this mutation a comparative study of the wild-type and the 'bud-flowering' flower type of C. vulgaris was initiated. Scanning electron microscopic analyses of flower organs as well as gene expression studies of an AP3-like and a SEPl-like gene in the different flower whorls of both flower types allowed identification of bracts, sepals and petals. However, loss of stamens in the 'bud-flowering' phenotype could not be explained by modified spatial expression of known organ identity genes. Therefore, new approaches (map-based cloning and differential transcriptome analysis) are now envisioned in order to elucidate the genetics of the 'bud-flowering' phenotype.