Rhododendron 'Rendezvous', which is a Hachmann hybrid documented as 'Marinus Koster' X R. degronianum ssp. yakushimanum, has been determined to be a diploid 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.
The hybridization efforts by John and Sally Perkins indicated that 'Rendezvous' was most likely a diploid.
Rhododendron 'Marinus Koster', which was determined to be a tetraploid, is the seed parent of the diploid 'Rendezvous'. This seems to indicate that 'Marinus Koster' only provided 1x gamete (13 chromosomes) to 'Rendezvous'.
'Marinus Koster' is the pollen parent to 'Point Defiance', which was determined to be a tetraploid using flow cytometry by Dr. Thomas Ranney, J.R. Jones, and Nathan Lynch. 'Anna', which was determined to be a diploid, is the seed parent of 'Point Defiance'.
Summary of Ploidy Levels
Diploid 'Anna',
Diploid 'Rendezvous',
Tetraploid 'Marinus Koster',
Tetraploid 'Point Defiance'
Source: John and Sally Perkins
John and Sally Perkins
