Analysis of a database of DNA profiles of 734 hybrid tea rose varieties

Over 10,000 Hybrid Tea rose varieties have been described. The large number of varieties and the size of the reference collections may cause problems in DUS (Distinctiveness, Uniformity, and Stability) testing. Molecular markers may help to solve these problems by providing high power to identify and recognise seedling-derived varieties based on unique genotypes, while grouping mutants into groups with identical marker scores. Here we describe the use of a set of 11 rose microsatellite markers to generate a database of molecular profiles of Hybrid Tea varieties. The data were analysed with respect to reproducibility, discriminative power, genetic (sub) structure, and correlation between molecular and DUS characteristics. The use of the markers in the DUS context is discussed with respect to the options 2 and 3 as they were formulated by the UPOV-BMT working group. It is concluded that an option 3 approach (granting of PBR based on distinctness observed with molecular markers) is feasible for ros