Development of supporting techniques for pot azalea (Rhododendron simsii hybrids) breeding focused on plant quality, disease resistance and enlargement of the assortment

For many decades, breeders have created new azalea cultivars at the Plant Unit of the Institute for Agricultural and Fisheries Research (ILVO, former DvP-CLO). In 2000, the Azalea Innovation Fund, in which all Belgian azalea growers are grouped, was established to fund partially this breeding work and since 2004, they participate in a research project on azalea. This project was divided into four topics; the first one was `Development of bio-assays for resistance screening against Phytophthora spp. and Cylindrocladium scoparium. Aiming at a more sustainable culture, workable screening tests are needed for resistance screening of the azalea gene pool and seedlings. The culture of azaleas has to cope with more and more competition of other flowering pot plants. However, azaleas that are novel in one way or another (fragrant flowers, ``savage'' types) should be able to address new markets. To pursue this aim, we should explore the use of interspecific hybridization to enlarge the current assortment. In the third part of the project, segregation of plant quality traits will be explored in the offspring of parents that reveal the extreme phenotypes of the range of the examined trait. DNA marker analysis will be done on some of these populations resulting in the construction of a genetic map.