'Hallelujah' is a Triploid

Rhododendron 'Hallelujah', which is a Harold Greer hybrid documented as 'The Honourable Jean Marie de Montague' x 'Kimberly', has been determined to be a triploid using flow cytometry by

Dr. João Loureiro, Dr. Silvia Castro, José Cerca Oliveira, 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.

Summary of Ploidy Levels

Diploid 'The Honourable Jean Marie de Montague',
Triploid 'Hallelujah'

Source: Greer Gardens
Source: Bob Fox

John and Sally Perkins

'Wild Affair' is a Diploid

Rhododendron 'Wild Affair', which is a Harold Greer hybrid documented as 'The Honourabele Jean Marie de Montague' x 'Moser's Maroon', 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.

Summary of Ploidy Levels

Diploid 'The Honourable Jean Marie de Montague',
Diploid 'Wild Affair'

Source: Van Veen Nursery

John and Sally Perkins

'Grand Slam' is a Tetraploid

Rhododendron 'Grand Slam', which is a Harold Greer hybrid documented as 'Trude Webster' x 'Lydia', 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 'Grand Slam' has as ancestors 'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby', 'Trude Webster', 'Antoon van Welie', and 'Lydia'.

Both of the parents of 'Grand Slam' have 'Pink Pearl' as an ancestor.

In the case of the tetraploid 'Grand Slam', a tetraploid crossed with a triploid produced a tetraploid indicating that reduced meiosis most likely occurred for both parents. In other words, 'Grand Slam' having 52 chromosomes received something similar to 26 chromosomes each from both the tetraploid 'Trude Webster' and the triploid 'Lydia'.

Rhododendron 'Grand Slam' was also determined to be a tetraploid using flow cytometry by Dr. Thomas Ranney, J.R. Jones, and Nathan Lynch.

Summary of Ploidy Levels

Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Lydia',
Triploid 'Pink Pearl',
Tetraploid 'Antoon van Welie',
Tetraploid 'Countess of Derby',
Tetraploid 'Grand Slam',
Tetraploid 'Trude Webster'

Source: Greer Gardens

John and Sally Perkins

'Very Berry' is a Tetraploid

Rhododendron 'Very Berry', which is a Harold Greer hybrid documented as 'Trude Webster' x 'The Honorable Jean Marie de Montague', 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.

'Very Berry' has 'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby', 'Trude Webster', and 'The Honorable Jean Marie de Montague' as ancestors. 'Verry Berry' appears to be another case where 'The Honorable Jean Marie de Montague' threw unreduced gametes.

Summary of Ploidy Levels

Diploid 'The Honorable Jean Marie de Montague',
Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Pink Pearl',
Tetraploid 'Countess of Derby',
Tetraploid 'Trude Webster',
Tetraploid 'Very Berry'

Source: Greer Gardens

John and Sally Perkins

'Sugar Pink' is a Triploid

Rhododendron 'Sugar Pink', which is a Harold Greer hybrid documented as 'Trude Webster' x ('Fawn' x 'Queen o' the May Group'), has 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.

'Sugar Pink' has 'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby', and 'Trude Webster' as ancestors.

Summary of Ploidy Levels

Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Pink Pearl',
Triploid 'Sugar Pink',
Tetraploid 'Countess of Derby',
Tetraploid 'Trude Webster'

Source: Greer Gardens

John and Sally Perkins

'Platinum Pearl' is a Fertile Triploid

Rhododendron 'Platinum Pearl', which is a Harold Greer hybrid documented as 'Trude Webster' x R. fortunei ssp. discolor, has 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.

'Platinum Pearl', which has 'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby', and 'Trude Webster' as ancestors, is the pollen parent of 'Gentle Giant'. 'Point Defiance', which has 'Marinus Koster' as an ancestor, is the seed parent of 'Gentle Giant'.

Notice 'Gentle Giant' represents the merging of 2 multi-generational polyploid lines, namely 1) 'Broughtonii' (3x), 'Pink Pearl' (3x), 'Countess of Derby (4x)' (polyploid), 'Trude Webster' (4x), 'Platinum Pearl' (3x), to 'Gentle Giant' (4x) and 2) 'Marinus Koster' (4x), 'Point Defiance' (4x), to 'Gentle Giant' (4x).

Summary of Ploidy Levels

Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Pink Pearl',
Triploid 'Platinum Pearl',
Tetraploid 'Countess of Derby',
Tetraploid 'Gentle Giant',
Tetraploid 'Marinus Koster',
Tetraploid 'Point Defiance',
Tetraploid 'Trude Webster'

Source: Greer Gardens

John and Sally Perkins

'Lydia' is a Fertile Triploid

Rhododendron 'Lydia', which is a Harold Greer hybrid documented as 'Antoon van Welie' x 'Day Dream Group', has 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.

'Lydia', which has 'Broughtonii', 'Pink Pearl', and 'Antoon van Welie' as ancestors, is the pollen parent of 'Grand Slam'. 'Trude Webster', which has 'Broughtonii', 'Pink Pearl', and 'Countess of Derby' as ancestors, is the seed parent of 'Grand Slam'.

Notice 'Grand Slam' represents the merging of 2 multi-generational polyploid lines, namely 1)'Broughtonii' (3x), 'Pink Pearl' (3x), 'Cynthia' (3x), 'Countess of Derby' (4x), 'Trude Webster' (4x), to 'Grand Slam' (4x) and 2)'Broughtonii' (3x), 'Pink Pearl' (3x), 'Antoon van Welie' (4x), Lydia (3x) to Grand Slam (4x).

Summary of Ploidy Levels

Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Lydia',
Triploid 'Pink Pearl',
Tetraploid 'Grand Slam',
Tetraploid 'Antoon van Welie',
Tetraploid 'Countess of Derby',
Tetraploid 'Trude Webster'

Source: Greer Gardens

John and Sally Perkins

'Trude Webster' is a Tetraploid

Rhododendron 'Trude Webster', which is a Harold Greer hybrid documented as 'Countess of Derby' X 'Countess of Derby', 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 hybridization work of Jim Barlup indicates that 'Trude Webster' is fertile in both directions when crossed with known and suspected polyploid elepidotes.

'Countess of Derby', which was determined to be a tetraploid, is the documented pollen parent of 'Anna Rose Whitney', which has been determined to be a triploid by the Coimbra based research team.

'Pink Pearl', which is the documented seed parent of 'Countess of Derby', was also determined to be a triploid by the Coimbra based research team.

'Cynthia', which is the documented pollen parent of 'Countess of Derby', was also determined to be a triploid by the Coimbra based research team.

The findings of the Coimbra based research team indicate 6 multi generational polyploid branches starting with the triploid 'Broughtonii', namely 1)'Broughtonii', 'Pink Pearl', 'Gomer Waterer', and 'Phyllis Korn', 2)'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby', and 'Anna Rose Whitney', 3)'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby', and 'Van',
4)'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby', and 'Lucky Strike',
5)'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby', 'Trude Webster', 'Platinum Pearl', and 'Gentle Giant' and 6)'Broughtonii', 'Pink Pearl', 'Antoon van Welie', 'Lydia', 'Trude Webster', and 'Grand Slam'.

Summary of Ploidy Levels

Triploid 'Anna Rose Whitney',
Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Gomer Waterer',
Triploid 'Lydia',
Triploid 'Lucky Strike',
Triploid 'Pink Pearl',
Triploid 'Phyllis Korn',
Triploid 'Platinum Pearl',
Triploid 'Van',
Tetraploid 'Antoon van Welie',
Tetraploid 'Countess of Derby',
Tetraploid 'Gentle Giant',
Tetraploid 'Grand Slam',
Tetraploid 'Trude Webster'

Source: Greer Gardens
Source: Bob Fox

John and Sally Perkins