'Phyllis Korn' x 'Trude Webster' is a Pentaploid

Two seedlings of Rhododendron 'Phyllis Korn' x 'Trude Webster', which is a Jim Barlup hybrid, have been determined to be a pentaploid 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 pentaploid seedlings of 'Phyllis Korn' (3X) x 'Trude Webster' (4X), a triploid by a tetraploid produced a pentaploid indicating that the triploid seed parent 'Phyllis Korn' was most likely unreduced. In other words, the pentaploid seedlings of 'Phyllis Korn' x 'Trude Webster' having 65 chromosomes most likely received 39 chromosomes from the triploid 'Phyllis Korn' and 26 chromosomes from the tetraploid 'Trude Webster'. Considering the parents are a triploid and a neotetraploid, meiosis may not be normal for either parent.

Summary of Ploidy Levels

Triploid 'Phyllis Korn'
Tetraploid 'Trude Webster',
Pentaploid 2 Seedlings of 'Phyllis Korn' x 'Trude Webster'

Source: Jim Barlap

John and Sally Perkins

'Peach Recital' is a Diploid

Rhododendron 'Peach Recital', which is a Jim Barlup hybrid documented as 'Percy Wiseman' x 'Summer Peach', 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.

Rhododendron 'Peach Recital' has as ancestors 'Broughtonii', 'Pink Pearl', 'Gomer Waterer', 'Phyllis Korn', and 'Summer Peach'.

Summary of Ploidy Levels

Diploid 'Diane',
Diploid 'Madame Carvalho',
Diploid 'Mrs. Lindsay Smith',
Diploid 'Peach Recital',
Diploid 'Summer Peach',
Triploid 'Broughtonii',
Triploid 'Gomer Waterer',
Triploid 'Phyllis Korn',
Triploid 'Pink Pearl'

Source: Jim Barlup

John and Sally Perkins

Rhododendron decorum ssp. diaprepes 'Gargantua' is a Tetraploid

Rhododendron decorum ssp. diaprepes 'Gargantua', which is often documented as a triploid, 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.

Rhododendron decorum ssp. diaprepes 'Gargantua' is known to be self fertile.

All elepidote Rhododendron species are documented to be diploids. Whether 'Gargantua' represents the sole anomaly from this rule is not known at this.

Summary of Ploidy Levels

Tetraploid Rhododendron decorum ssp. diaprepes 'Gargantua'

Source: Whitney Nursery
Source: Jim Barlup

John and Sally Perkins