Rhododendron breeders work with a genus that collectively has a broad flowering season. However, many individual species or cultivars flower for much shorter periods. To make many desirable crosses, it becomes necessary for the breeder to store pollen. Existing literature offers only brief recommendations on storage conditions in reports by Bowers (1932), Lee (1958), and Schroeder and Bump (1982) and a single, more detailed report by Visser (1955) that few breeders have available.
This study outlines the relative value of a range of storage conditions for short-term (two weeks or less) pollen storage of two cultivars of evergreen azaleas. Long-term storage is generally done successfully by using variations of the desiccator-freezing method, as described by Schroeder and Bump (1982) and Visser (1955).
Available at: http://works.bepress.com/mark_widrlechner/95/