H: Wednesday, September 29, 2010

'Arneson's Gem' is a Tetraploid

Rhododendron 'Arneson's Gem', which appears to contain Rhododendron molle and an exbury azalea, 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.

The Perkins's Pollen Based Ploidy Test indicated that 'Arneson's Gem' was most likely a tetraploid.

Rhododendron 'Arneson's Gem' is pollen fertile but appears to be seed sterile. 'Chickasaw', which was found by Clarence Towe in the wild and was determined by Dr. Thomas Ranney and Nathan Lynch to be a tetraploid using flow cytometry, is seed fertile but produces no pollen.

These fertility issues may indicate that both of these tetraploid hybrids, one man made and the other occurring naturally in the wild, are aneuploids having a chromosome count near tetraploid.

Summary of Ploidy Levels

Diploid Rhododendron molle
Tetraploid 'Arneson's Gem'
Tetraploid 'Chickasaw'

Source: John and Sally Perkins

John and Sally Perkins
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