Rhododendron 'Walloper No. 10', which is a Halfdan Lem hybrid documented as 'Anna' x 'Marinus Koster', has 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 'Walloper No. 10', a diploid crossed with a tetraploid produced a tetraploid indicating that unreduced meiosis may have occurred for the diploid parent. In other words, 'Pink Walloper' having 52 chromosomes received something similar to 26 chromosomes from the diploid 'Anna' and 26 chromosomes from the tetraploid 'Marinus Koster'.
Summary of Ploidy Levels
Diploid 'Anna',
Diploid 'Norman Gill',
Diploid 'The Honourable Jean Marie de Montague',
Triploid 'El Camino',
Tetraploid 'Lem's Monarch',
Tetraploid 'Marinus Koster',
Tetraploid 'Pink Walloper',
Tetraploid 'Point Defiance',
Tetraploid 'Walloper No. 10'
Source: Van Veen Nursery
John and Sally Perkins
