'Naselle' X 'Rwain' is a Diploid

One seedling of Rhododendron 'Naselle' X 'Rwain', which was raised by Marc Colombel, 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.

In the case of the diploid seedling of 'Naselle' (2X) X 'Rwain'(3X), a diploid by a triploid produced a diploid indicating that triploid pollen parent 'Rwain' acted as a diploid. In other words, the diploid seedlings of 'Naselle' X 'Rwain' having 26 chromosomes most likely received 13 chromosomes from the diploid 'Naselle' and 13 chromosomes from the triploid 'Rwain'.

Summary of Ploidy Levels

Diploid 'Hotei',
Diploid 'Naselle',
Diploid 1 Seedling of 'Naselle' X 'Rwain',
Triploid 'Rwain',
Triploid 1 Seedling of 'Hotei' x 'Rwain'

Source Marc Colombel

John and Sally Perkins

'Hotei' x 'Rwain' is a Triploid

One seedling of Rhododendron 'Hotei' x 'Rwain', which was raised by Marc Colombel, 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.

In the case of the triploid seedling of 'Hotei' (2X) x 'Rwain' (3X), a diploid by a triploid produced a triploid indicating that triploid seed parent 'Rwain' acted as a tetraploid. In other words, the triploid seedlings of 'Hotei' x 'Rwain' having 39 chromosomes most likely received 13 chromosomes from the diploid 'Hotei' and 26 chromosomes from the triploid 'Rwain'.

Summary of Ploidy Levels

Diploid 'Hotei',
Diploid 'Naselle',
Diploid 1 Seedling of 'Naselle' X 'Rwain',
Triploid 'Rwain',
Triploid 1 Seedling of 'Hotei' x 'Rwain'

Source Marc Colombel

John and Sally Perkins

'Summer Peach' is a Diploid

Rhododendron 'Summer Peach', which is a Jim Barlup hybrid documented as 'Whitney's Late Peach' X 'Phyllis Korn', 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 'Summer Peach' has as ancestors 'Broughtonii', 'Pink Pearl', 'Gomer Waterer', and 'Phyllis Korn' which are all triploids. 'Summer Peach' has as descendants 'Peach Recital' and 'Summer Wind' which are both diploids.

Summary of Ploidy Levels

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

Source: Whitney Nursery

John and Sally Perkins

'J.G. Millais' is a Diploid

Rhododendron 'J.G. Millais', which is a 1915 Waterer hybrid documented as 'Ascot Brilliant' x 'Pink Pearl', 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 'J.G. Millais' has as ancestors 'Broughtonii' and 'Pink Pearl' which are both triploids.

Summary of Ploidy Levels

Diploid 'J.G. Millais',
Triploid 'Broughtonii',
Triploid 'Pink Pearl'

Source: Van Veen Nursery

John and Sally Perkins

'Gomer Waterer' is a Fertile Triploid

Rhododendron 'Gomer Waterer', which is a 1900 Waterer hybrid documented as 'Madame Carvalho' x 'Pink Pearl', 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.

'Gomer Waterer', which has 'Broughtonii' and 'Pink Pearl' as ancestors, is documented as the pollen parent of 'Phyllis Korn', which has been determined to be a triploid. 'Diane', which is a diploid, is the seed parent of 'Phyllis Korn'.

'Gomer Waterer' is a 19th century hybrid hardy in zone 6.

Summary of a Polyploidy Ancestor Chain involving 'Gomer Waterer'

'Broughtonii' to 'Pink Pearl' to 'Gomer Waterer' to 'Phyllis Korn' to ('Phyllis Korn' X 'Trude Webster')

Summary of Fertile Triploids

'Anna Rose Whitney',
'Betty Wormald',
'Broughtonii',
'Cynthia',
'Cotton Candy',
'Gomer Waterer',
'Lydia',
'Platinum Pearl',
'Phyllis Korn',
'Pink Pearl',
'Rwain',
'Taurus',
'Val d'Aulnay'

Summary of Triploids from the 19th Century

'Broughtonii' 1840,
'Cynthia' 1856,
'Beauty of Littleworth' 1884,
'Pink Pearl' 1892,
'Gomer Waterer' 1900

Summary of Polyploids Hardy in Zone 6

'Anita Gehnrich',
'August Lamken',
'Cynthia',
'Gartendirektor Rieger',
'Gomer Waterer',
'Grace Seabrook',
'Hallelujah',
'Phyllis Korn',
'Solidarity',
'Taurus',
'Trude Webster'

Summary of Ploidy Levels

Diploid 'Diane',
Diploid 'Madame Carvalho',
Triploid 'Anita Gehnrich',
Triploid 'Anna Rose Whitney',
Triploid 'August Lamken',
Triploid 'Beauty of Littleworth',
triploid 'Betty Wormald',
Triploid 'Broughtonii',
Triploid 'Cotton Candy',
Triploid 'Cynthia',
Triploid 'Gartendirektor Rieger',
Triploid 'Gomer Waterer',
Triploid 'Grace Seabrook',
Triploid 'Hallelujah',
Triploid 'Lydia',
Triploid 'Phyllis Korn',
Triploid 'Pink Pearl',
Triploid 'Platinum Pearl',
Triploid 'Rwain',
Triploid 'Solidarity',
Triploid 'Taurus',
Triploid 'Val d'Aulnay',
Tetraploid 'Trude Webster',
Pentaploid (2 Seedlings from 'Phyllis Korn' X 'Trude Webster')

Source: John and Sally Perkins

John and Sally Perkins

'Phyllis Korn' is a Fertile Triploid

Rhododendron 'Phyllis Korn', which is a Korn hybrid documented as 'Diane' x 'Gomer Waterer', 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.

'Phyllis Korn', which has 'Broughtonii', 'Diane', 'Pink Pearl', and 'Gomer Waterer' as ancestors, is documented as the pollen parent of 'Summer Peach', which has been determined to be a diploid. Jim Barlup produced several seedlings using 'Phyllis Korn' as the seed parent and 'Trude Webster' as the pollen parent.

'Phyllis Korn' is hardy in zone 6.

'Peach Recital' and 'Summer Wind' are diploid offspring of 'Summer Peach'.

'Trude Webster' has as ancestors 'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby' and has as descendants 'Platinum Pearl', 'Grand Slam', and 'Gentle Giant'

Summary of Ploidy Levels

Diploid 'Diane',
Diploid 'Madame Carvalho',
Diploid 'Mrs. Lindsay Smith',
Diploid 'Peach Recital',
Diploid 'Summer Peach',
Diploid 'Summer Wind',
Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Gomer Waterer',
Triploid 'Platinum Pearl',
Triploid 'Phyllis Korn',
Triploid 'Pink Pearl',
Tetraploid 'Countess of Derby',
Tetraploid 'Gentle Giant',
Tetraploid 'Grand Slam',
Tetraploid 'Trude Webster'

Source: John and Sally Perkins

John and Sally Perkins

'Pink Pearl' is a Fertile Triploid.

Rhododendron 'Pink Pearl', which is a Waterer hybrid documented as 'George Hardy' x 'Broughtonii', 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.

'Pink Pearl' is sometimes referred to as the first commercially successful Rhododendron.

Other flow cytometry results from this research team include the following

'Broughtonii', the documented pollen parent of 'Pink Pearl', is a triploid.

'Antoon van Welie', which has 'Pink Pearl' as a documented seed parent, is a tetraploid.

'Gomer Waterer', which has 'Pink Pearl' as a documented pollen parent, is a
triploid.

'Graf Zeppelin', which has 'Pink Pearl' as a documented seed parent, is a
diploid.

'J.G. Millais', which has 'Pink Pearl' as a documented pollen parent, is a diploid.

'Topsvoort Pearl', which is documented sport of 'Pink Pearl', is a triploid.

'Ebony Pearl', which is documented sport of 'Pink Pearl', is a triploid.

'Mother of Pearl', which is a documented sport of 'Pink Pearl', is a diploid.

'Phyllis Korn', which has 'Gomer Waterer' as a document pollen parent, is a triploid.

'Countess of Derby', which has 'Pink Pearl' as the documented seed parent and 'Cynthia' as the documented pollen parent, is a tetraploid.

'Trude Webster', which is documented as 'Countess of Derby' selfed, is a tetraploid.

'Diane', which is documented as the seed parent of 'Phyllis Korn', is a diploid.

'Summer Peach', which has 'Phyllis Korn' as a documented pollen parent, is a diploid.

'Summer Wind' and 'Peach Recital', which have 'Summer Peach' as a documented pollen parent, are a diploids.

Seedlings of Jim Barlup's cross of 'Phyllis Korn' by 'Trude Webster' have been determined to be pentaploids.

These results from the researchers at the University of Coimbra indicate 4 generations of fertile triploids, that triploids can produce diploid, triploid, tetraploid, and pentaploid offspring, and sports of triploids can be both ploidy stable and ploidy unstable.

Summary of Ploidy Levels

Diploid 'Diane',
Diploid 'Graf Zeppelin',
Diploid 'J.G. Millais',
Diploid 'Mother of Pearl',
Diploid 'Peach Recital,
Diploid 'Summer Peach',
Diploid 'Summer Wind',
Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Ebony Pearl',
Triploid 'Gomer Waterer',
Triploid 'Phyllis Korn',
Triploid 'Pink Pearl',
Triploid 'Topsvoort Pearl',
Tetraploid 'Antoon van Welie',
Tetraploid 'Countess of Derby',
Tetraploid 'Trude Webster',
Pentaploid Seedlings of 'Phyllis Korn' X 'Trude Webster'

Source: Whitney Nursery

John and Sally Perkins

'Hurricane' is a Diploid

Rhododendron 'Hurricane', which is a William Whitney hybrid documented as 'Mrs Furnivall' x 'Anna Rose Whitney', 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 'Hurricane' has as ancestors 'Broughtonii', 'Cynthia', 'Pink Pearl', 'Countess of Derby', 'Mrs Furnivall', and 'Anna Rose Whitney'.

In the case of 'Hurricane', a diploid 'Mrs. Furnivall' crossed with a triploid 'Anna Rose Whitney' produced a diploid indicating 'Anna Rose Whitney' most likely contributed only a 1x gamete (13 chromosomes) to 'Hurricane'.

Summary of Ploidy Levels

Diploid 'Hurricane',
Diploid 'Mrs. Furnivall',
Triploid 'Anna Rose Whitney',
Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Pink Pearl',
Tetraploid 'Countess of Derby'

Source: Whitney Nursery

John and Sally Perkins