H: Tuesday, March 22, 2011

(cumberlandense X viscosum) X 'Apricot Surprise' is a Triploid

Two seedlings of [(Rhododendron cumberlandense X Rhododendron viscosum) X 'Apricot Surprise'], which is a John and Sally Perkins hybrid, have 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.

Rhododendron cumberlandense and Rhododendron viscosum are diploid species. 'Apricot Surprise' is a tetraploid.

In the case of these 2 triploids (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 cumberlandense,
Diploid Rhododendron viscosum,
Triploid 2 seedlings from [(Rhododendron cumberlandense X Rhododendron viscosum) X 'Apricot Surprise' ],
Tetraploid 'Apricot Surprise'

Seedlings from this same cross were sold at the November 14, 2010 Founders Day Meeting of the ARS Massachusetts Chapter and at the November 20, 2010 Banquet of the New England Rock Garden Society.

These seedlings were 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
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