Three seedlings of Rhododendron 'Horizon Monarch' X 'Rwain', which were raised by Marc Colombel, have been determined to be a tetraploid 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 tetraploid seedling of 'Horizon Monarch' (4x) X 'Rwain' (3X), a tetraploid by a triploid produced a tetraploid indicating that triploid pollen parent 'Rwain' acted as a tetraploid. In other words, the tetraploid seedlings of 'Horizon Monarch' X 'Rwain' having 52 chromosomes most likely received 26 chromosomes from the tetraploid 'Horizon Monarch' and 26 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
