One seedling of Rhododendron 'Horizon Monarch' X 'Rwain', which was raised by Marc Colombel, has been determined to be a triploid using flow cytometry by
Dr. João Loureiro, Dr. Silvia Castro, José Cerca, and Mariana Castro
Plant Ecology and Evolution Group,
Centre for Functional Ecology,
Department of Life Sciences,
Faculty of Science and Technology,
University of Coimbra, Portugal.
In the case of the triploid seedling of 'Horizon Monarch' (4X) X 'Rwain' (3X), a tetraploid by a triploid produced a triploid indicating that triploid pollen parent 'Rwain' acted as a diploid. In other words, the triploid seedlings of 'Horizon Monarch' X 'Rwain' having 52 chromosomes most likely received 26 chromosomes from the tetraploid 'Horizon Monarch' and 13 chromosomes from the triploid 'Rwain'.
Summary of Ploidy Levels
Triploid 'Rwain',
Triploid 1 Seedling of 'Horizon Monarch' X 'Rwain'
Tetraploid 'Horizon Monarch',
Tetraploid 3 Seedlings of 'Horizon Monarch' X 'Rwain'
Source Marc Colombel
John and Sally Perkins
