AFLP analysis for characterization of Osteospermum germplasm

The cultivated genus Osteospermum belongs to the plant family Compositae (Asteraceae). Their native habitat is in South African mountains, therefore these plants are also known under the common name 'African Daisy'. Osteospermums are half hardy or hardy perennial ornamental plants. The genus Osteospermum contains about seventy different species, all perennial plants. The perennial cultivated varieties, not to be confused with the annuals and less valuable cultivated hybrids of Dimorphoteca aurantiaca, are in turn hybrids of O. ecklonis, O. jucundum and other species, and hybrid combinations are often unknown. Also for this hybrid condition they are usually not available from seed, but as vegetatively propagated clones. New varieties are being bred continuously because of the increased economic importance in the production of flowering pot plants and of the increasing demand for accessions with new bright colours and for novel miniature plants. The genus Osteospermum already meets these criteria in its native habitat of South African mountains, and there has been much recent work by botanists and plant breeders to further enhance the natural characteristics of those seventy species of wild plants. Indeed, a characterisation of cultivated Osteospermum germplasm becomes necessary in our country in order to protect the consumers' and breeders' rights, and to help the national breeders in the choice of the parents for a new cross. Moreover, the characterisation by means of molecular markers supplies a way to evaluate biodiversity among commercial varieties and wild relatives. Molecular marker (RAPD) analysis was already demonstrated to be an useful tool to identify Osteospermum varieties and to study their genetic affinities (Faccioli et al., 1999). AFLP analysis has been now carried out on a wide collection of 106 Osteospermum composed by wild species and cultivars belonging to English, Italian and Danish breeding groups. The AFLP protocol has been set up for this ornamental. All the accessions were then tested with four AFLP primers combinations, leading to the undoubtful characterisation of genotypes and to a more accurate understanding of the relationships between the Osteospermum species and cultivars.