Rhododendron prinophyllum X Rhododendron calendulaceum "Engine Gap", which is a John and Sally Perkins hybrid, has been determined to be a triploid using flow cytometry by
Dr. João Loureiro, Dr. Silvia Castro, 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.
Rhododendron prinophyllum is diploid. Rhododendron calendulaceum is a tetraploid species.
In this case of this triploid (39 chromosomes), a diploid crossed with a tetraploid produced a triploid indicating normal meiosis occurred where the diploid contributed a 1x gamete (13 chromosomes) and the tetraploid contributed a 2x gamete (26 chromosomes).
Summary of Ploidy Levels
Diploid Rhododendron prinophyllum,
Triploid Rhododendron prinophyllum X Rhododendron calendulaceum "Engine Gap",
Tetraploid Rhododendron calendulaceum
This seedling was grown on by
Lindy Johnson
Appalachian Native Plants
676 Waddell Road
PO Box 736
Mountain City, TN 37683
Source: John and Sally Perkins
Source: Appalachian Native Plants
John and Sally Perkins
