Towards improvement of Impatiens^©

Common impatiens, Impatiens walleriana, have traditionally been the most popular annual flower used for landscaping. However, impatiens downy mildew (Plasmopara obducens), a pathogen which has recently become virulent against this species, leaves plants defoliated and commercially unviable. Research was started to identify other species, from a genus of over one thousand, which were more resistant to the disease. Screening identified many species with significantly higher resistance, as well as trends in which species were susceptible. Using a range of breeding and propagation tools, we explored different ways to improve common impatiens and integrate the resistance we identified. These included making efforts to better characterize the available germplasm, ploidy manipulation, tissue culture, and interspecific hybridization. Here we describe existing techniques for impatiens improvement, as well as the modifications we have developed for them.