'Gentle Giant' is a Tetraploid

Rhododendron 'Gentle Giant', which is a D. Sanders hybrid documented as 'Point Defiance' x 'Platinum Pearl', 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 'Gentle Giant' has as ancestors 'Broughtonii', 'Pink Pearl', 'Cynthia', 'Countess of Derby', 'Trude Webster', 'Platinum Pearl', 'Norman Gill', 'The Honourable Jean Marie de Montague', 'Anna', 'Marinus Koster', and 'Point Defiance'.

Both of the parents of 'Gentle Giant' have 'George Hardy' as an ancestor.

In the case of the tetraploid 'Gentle Giant', a tetraploid crossed with a triploid produced a tetraploid indicating that reduced meiosis most likely occurred for both parents. In other words, 'Gentle Giant' having 52 chromosomes received something similar to 26 chromosomes each from both the tetraploid 'Point Defiance' and the triploid 'Platinum Pearl'.

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

Summary of Ploidy Levels

Diploid 'Anna',
Diploid 'Norman Gill',
Diploid 'The Honourable Jean Marie de Montague',
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

'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

'Countess of Derby' is a Tetraploid

Rhododendron 'Countess of Derby', which is a 1913 Henry White hybrid documented as 'Pink Pearl' x 'Cynthia', 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 'Countess of Derby' is the oldest known tetraploid large leaf elepidote. 'Pink Pearl' and 'Cynthia' are both triploids.

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

In the case of the tetraploid 'Countess of Derby', a triploid crossed with a triploid produced a tetraploid indicating that reduced meiosis occurred for either or both triploid parents. In other words, 'Countess of Derby' having 52 chromosomes either 1) received something similar to 26 chromosomes from each triploid parent or 2) received something similar to 39 chromosomes from one triploid parent and 13 chromosomes from the other triploid parent.

Summary of Ploidy Levels

Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Pink Pearl',
Triploid 'Platinum Pearl',
Tetraploid 'Countess of Derby',
Tetraploid 'Gentle Giant',
Tetraploid 'Grand Slam',
Tetraploid 'Trude Webster'

Source: Van Veen Nursery

John and Sally Perkins

'Antoon van Welie' is a Tetraploid

Rhododendron 'Antoon van Welie', which is a pre 1930 Endtz hybrid documented as 'Pink Pearl' x R. catawbiense, 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 'Antoon van Welie' has 'Broughtonii' and 'Pink Pearl' as a ancestors and 'Lydia' and 'Grand Slam' as descendants.

In the case of the tetraploid 'Antoon van Welie', a triploid crossed with a likely diploid produced a tetraploid indicating that unreduced meiosis occurred for either the triploid 'Pink Pearl' or the likely diploid R. catawbiense. In other words, 'Antoon van Welie' having 52 chromosomes either 1) received all 39 of 'Pink Pearl' chromosomes plus 13 from R. catawbiense or 2) received 26 from 'Pink Pearl' plus all 26 of R. catawbiense chromosomes.

Summary of Ploidy Levels

Triploid 'Broughtonii',
Triploid 'Lydia',
Triploid 'Pink Pearl',
Tetraploid 'Antoon van Welie',
Tetraploid 'Grand Slam',
Tetraploid 'Trude Webster'

Source: Whitney Nursery
Source: Van Veen Nursery

John and Sally Perkins

'One Thousand Butterflies' is a Diploid

Rhododendron 'One Thousand Butterflies', which is a J. G. Lofthouse hybrid documented as 'Lem's Cameo' x 'Pink Petticoats', 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 'Anna',
Diploid 'Lem's Cameo',
Diploid 'One Thousand Butterflies',
Diploid 'Norman Gill',
Diploid 'The Honorable Jean Marie de Montague'

Source Marc Colombel

John and Sally Perkins

Reminder: P4M Workday: Planeview Nursery - No Meeting @ Sat Nov 27 10am - 12pm (ARS Massachusetts Chapter Calendar)

more details » P4M Workday: Planeview Nursery - No Meeting No Meeting When Sat Nov 27 10am – 12pm Eastern Time Where 770 Wapping Road, Portsmouth, RI (map) Calendar ARS Massachusetts Chapter Calendar Who • John Perkins - creator

Invitation from Google Calendar You are receiving this email at the account john.a.perkins@gmail.com because you are subscribed for reminders on calendar ARS Massachusetts Chapter Calendar. To stop receiving these notifications, please log in to https://www.google.com/calendar/ and change your notification settings for this calendar.

'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

Reminder: Return Van Veen Order @ Thu Nov 25 9pm - 11:30pm (ARS Massachusetts Chapter Calendar)

more details » Return Van Veen Order Van Veen Orders Due and Returned to George Hibben When Thu Nov 25 9pm – 11:30pm Eastern Time Where Returned to George Hibben (map) Calendar ARS Massachusetts Chapter Calendar Who • John Perkins - creator

Invitation from Google Calendar You are receiving this email at the account john.a.perkins@gmail.com because you are subscribed for reminders on calendar ARS Massachusetts Chapter Calendar. To stop receiving these notifications, please log in to https://www.google.com/calendar/ and change your notification settings for this calendar.

'Graf Zeppelin' is a Diploid

Rhododendron 'Graf Zeppelin', which is a C. B. Van Nes hybrid documented as 'Pink Pearl' x 'Mrs. Charles S. Sargent', 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 'Graf Zeppelin' has as ancestors 'Broughtonii' and 'Pink Pearl' which are both triploids.

Summary of Ploidy Levels

Diploid 'Graf Zeppelin',
Triploid 'Broughtonii',
Triploid 'Pink Pearl'

Source: Van Veen Nursery
Source: Whitney Nursery

John and Sally Perkins

It is 1913 so What Do You Do?

It is a Beautiful Spring Day in 1913 so What Do You Do?
John and Sally Perkins


Figure 1: Triploids can be Fertile and can create a Bidirectional Pathway Between Ploidy Levels

In spring 1913, George V is the first Windsor King of England, Woodrow Wilson is serving his first term as President of the United States, and World War I is a future event. The 2 most popular Rhododendrons in the world are 'Pink Pearl', a 1890's Waterer hybrid, and 'Cynthia', a 1850's Noble and Standish hybrid. On a beautiful spring day in 1913 if you are Henry 'Harry' White, a nursery manager in Sunningdale, England you cross 'Pink Pearl' by 'Cynthia'. You later name a seedling from this cross 'Countess of Derby'.

In spring 1961, John Kennedy is the young handsome President of the United States and Vietnam is a country unknown to most Americans. On a beautiful spring day in 1961 if you are Harold Greer, living in Eugene, Oregon, you self 'Countess of Derby'. You later name a seedling from this cross 'Trude Webster'.

In spring 1969, Richard Nixon is the President of the United States and Watergate is simply an office building in the DC area. On a beautiful spring day in 1969 if you are Robert Korn in Renton, Washington, you place the pollen from 'Gomer Waterer', a 1900 Waterer 'Pink Pearl' hybrid, onto 'Diane'. You later name a seedling from this cross 'Phyllis Korn'.

In spring 1988, George H. Bush is the Vice President of the United States and Iraq is simply a country somewhere in the Middle East. On a beautiful spring day in 1988 if you are Jim Barlup, living in Bellevue, Washington, you cross 'Whitney's Late Peach' by 'Phyllis Korn'. You later name a seedling from this cross 'Summer Peach'.

In spring 2001, George W. Bush is the President of the United States and the Twin Towers in New York City are still standing. On a beautiful spring day in 2001 if you are Jim Barlup, living in Bellevue, Washington, you cross 'Phyllis Korn' by 'Trude Webster' to create several viable offspring.

So what have you done starting in 1913?

Well you took 2 fertile triploids from the 19th century, namely 'Pink Pearl' and 'Cynthia' and created a tetraploid, namely 'Countess of Derby'. You then selfed the tetraploid 'Countess of Derby' creating a tetraploid, namely 'Truder Webster'. You then placed pollen from the triploid 'Gomer Waterer' onto a diploid seed parent, namely 'Diane' creating a triploid, namely 'Phyllis Korn'. You then used the pollen of a triploid, namely Phyllis Korn' to create a diploid, namely 'Summer Peach'. You then placed the pollen of the tetraploid 'Trude Webster' onto the triploid seed parent 'Phyllis Korn' and produced a series of pentaploid seedlings. See figure 1.

By doing so you ended the myth that triploids are always sterile showing that triploids can be both seed and pollen parents. Moreover, triploids, when used in hybridization, produce both reduced and unreduced gametes. You demonstrated that triploids provide a pathway for the bidirectional transfer of genes between diploids, triploids, tetraploids, and pentaploids.

It took you a few beautiful spring days doing crosses, a few changes of names and addresses, nearly 90 years, and a team of young researchers at the University of Coimbra in Portugal to confirm your results but all in all not a bad piece of work.

Summary of Ploidy Levels

Diploid 'Diane',
Diploid 'Madame Carvalho',
Diploid 'Summer Peach',
Triploid 'Broughtonii',
Triploid 'Cynthia',
Triploid 'Gomer Waterer',
Triploid 'Pink Pearl',
Triploid 'Phyllis Korn',
Tetraploid 'Countess of Derby',
Tetraploid 'Trude Webster', and
Pentaploid Seedlings of 'Phyllis Korn' X 'Trude Webster'

Flow cytometry to determine ploidy levels performed 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 following people and organizations donored samples for this reasearch:

John Abbott,
Vivian Abney of East Fork Nursery,
Arnold Arboretum,
Audra State Park, WV,
Jim Barlup,
Barlett Arboretum,
Jane Brooks,
Joe Bruso,
Canobie Lake, NH,
Dick Cavender,
Werner Brack,
Ned Brockenbrough,
Marc Colombel,
Bruce Clyburn,
Connecticut College Arboretum,
Mike Creel,
Al Fitzburg,
Robert Fox,
Harold Greer of Greer Gardens,
George Hibben,
Highstead Arboretum,
Don Hyatt,
Lindy Johnson of Appalachian Native Plants,
Richard Jaynes of Broken Arrow Nursery,
Doug Jolley,
Fred Knippel,
Longwood Gardens,
Ron Miller,
Dick Murcott,
John and Sally Perkins,
Planeview Nursery,
Ron Rabideau of RareFind Nursery,
Ellie Sather of Whitney Gardens,
Stoddard Blog, NH,
John Thornton,
Hendrik Van Oostand of Azaleatuin,
Kathy Van Veen of Van Veen Nursery

'Kathy Van Veen' is a Diploid

Rhododendron 'Kathy Van Veen', which is a documented as a sport of 'The Honorable Jean Marie de Montague', 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 'Kathy Van Veen',
Diploid 'The Honorable Jean Marie de Montague'

Source Marc Colombel

John and Sally Perkins

'Voluptuous' is a Diploid

Rhododendron 'Voluptuous', which is a Werner Brack hybrid documented as 'Scintillation' X 'Mary Belle', 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 'Voluptuous'

Source: Whitney Nursery

John and Sally Perkins

Reminder: P4M Workday: Planeview Nursery - No Meeting @ Sat Nov 27 10am - 12pm (ARS Massachusetts Chapter Calendar)

more details » P4M Workday: Planeview Nursery - No Meeting No Meeting When Sat Nov 27 10am – 12pm Eastern Time Where 770 Wapping Road, Portsmouth, RI (map) Calendar ARS Massachusetts Chapter Calendar Who • John Perkins - creator

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'Betty Wormald' is a Fertile Triploid

Rhododendron 'Betty Wormald', which is a 1907 Koster hybrid documented as a 'George Hardy' hybrid, 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.

Rhododendron 'Betty Wormald' is documented as the seed parent of 'Scandinavia'.

Summary of Ploidy Levels

Triploid 'Betty Wormald'

Source: Van Veen Nursery

John and Sally Perkins

Van Veen Order Deadline

A final reminder that ALL Chapter member orders are due by November 25th. Send your order along before you sit down to enjoy Thanksgiving dinner. The combined order will be send off to Van Veen the following day. If you have already sent your list, many thanks.

George

Ploidy Levels in Rhododendrons

Although most Rhododendrons are diploids having 26 chromosomes, diploid, triploid, tetraploid, pentaploid, and even higher ploidy level Rhododendrons do exist.

Although most Rhododendron species are diploids, tetraploid Rhododendron species exist.

Summary of Ploidy Levels for Rhododendrons

Diploid - 26 chromosomes
Triploid - 39 chromosomes
Tetraploid - 52 chromosomes
Pentaploid - 65 chromosomes
Hexaploid - 78 chromosomes
Octaploid - 104 chromosomes

Summary of Expected Outcome from Normal Rhododendron Crosses

Diploid X Diploid yields Diploid
Tetraploid X Tetraploid yields Tetraploid
Diploid X Tetraploid yields Triploid

Summary of Known Outcomes from Rhododendron Crosses

Diploid X Diploid yields Diploid, Triploid
Tetraploid X Tetraploid yields Tetraploid
Diploid X Tetraploid yields Diploid, Triploid, Tetraploid
Diploid X Triploid yields Diploid, Triploid, Tetraploid
Triploid X Tetraploid yields Triploid, Tetraploid, Pentaploid

John and Sally Perkins

'L'Engin' is a Tetraploid

Rhododendron 'L'Engin', which is a Christian de la Sablière hybrid documented as 'Val d'Aulnay' X 'Lem's Cameo', 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.

In the case of the tetraploid 'L'Engin', a triploid crossed with a diploid produced a tetraploid indicating that unreduced meiosis occurred for either the triploid 'Val d'Aulnay' or the diploid 'Lem's Cameo'. In other words, 'L'Engin' having 52 chromosomes either 1) received all 39 of 'Val d'Aulnay' chromosomes plus 13 from 'Lem's Cameo' or 2) received 26 from 'Val d'Aulnay' plus all 26 of 'Lem's Cameo' chromosomes.

Summary of Ploidy Levels

Diploid 'Anna',
Diploid 'Lem's Cameo',
Diploid 'Norman Gill',
Diploid 'The Honorable Jean Marie de Montague',
Triploid 'Val d'Aulnay',
Tetraploid L'Engin

Source Marc Colombel

John and Sally Perkins

Reminder: Return Van Veen Order @ Thu Nov 25 9pm - 11:30pm (ARS Massachusetts Chapter Calendar)

more details » Return Van Veen Order Van Veen Orders Due and Returned to George Hibben When Thu Nov 25 9pm – 11:30pm Eastern Time Where Returned to George Hibben (map) Calendar ARS Massachusetts Chapter Calendar Who • John Perkins - creator

Invitation from Google Calendar You are receiving this email at the account john.a.perkins@gmail.com because you are subscribed for reminders on calendar ARS Massachusetts Chapter Calendar. To stop receiving these notifications, please log in to https://www.google.com/calendar/ and change your notification settings for this calendar.

'Val d'Aulnay' is a Fertile Triploid

Rhododendron 'Val d'Aulnay', which is a Croux and Fils hybrid, 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.

Rhododendron 'Val d'Aulnay' is the seed parent of 'L'Engin', which has been determined to be tetraploid. 'Lem's Cameo', which has been determined to be diploid, is the pollen parent of 'L'Engin'.

In the case of the tetraploid 'L'Engin', a triploid crossed with a diploid produced a tetraploid indicating that unreduced meiosis occurred for either the triploid 'Val d'Aulnay' or the diploid 'Lem's Cameo'. In other words, 'L'Engin' having 52 chromosomes either 1) received all 39 of 'Val d'Aulnay' chromosomes plus 13 from 'Lem's Cameo' or 2) received 26 from 'Val d'Aulnay' plus all 26 of 'Lem's Cameo' chromosomes.

Summary of Ploidy Levels

Diploid 'Lem's Cameo',
Triploid 'Val d'Aulnay',
Tetraploid L'Engin

Source Marc Colombel

John and Sally Perkins

'Cotton Candy' is a Fertile Triploid

Rhododendron 'Cotton Candy', which is a Henny and Wennekamp hybrid documented as 'Loderi Venus' x 'Marinus Koster', 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.

Rhododendron 'Cotton Candy' has been successfully used as both a seed and pollen parent by L. L. Newcomb and M. Stockman.

In the case of the triploid (39 chromosomes) 'Cotton Candy', a diploid crossed with a tetraploid produced a triploid indicating normal meiosis occurred where the diploid 'Loderi Venus' contributed a 1x gamete (13 chromosomes) and the tetraploid 'Marinus Koster' contributed a 2x gamete (26 chromosomes).

Summary of Ploidy Levels

Diploid 'Loderi Venus',
Triploid 'Cotton Candy',
Tetraploid 'Marinus Koster'

Source: Whitney Nursery

John and Sally Perkins

Cross of Year 2010

Cross of the Year for 2010

'Marydel' X R. calendulaceum 'Smokey Mountaineer'
['Hachmann's Polaris' X ('Scarlet Romance' X 'Red Bomber')]

Cross of the Year for 2009

'Marydel' X R. colemanii
'Vinecrest' X 'Planeta'

'Marinus Koster' is a Tetraploid

Rhododendron 'Marinus Koster', which is a 1937 Koster hybrid documented as R. griffithianum hybrid, 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.

'Marinus Koster' is one of the oldest known tetraploid large leaf elepidote hybrid.

'Marinus Koster' is a parent of 'Arnold Piper', 'Cotton Candy', 'El Camino', 'Lem's Monarch', 'Point Defiance', and 'Rendezvous'.

Halfdan Lem named several crosses of 'Anna' by 'Marinus Koster'.

Summary of Ploidy Levels

Diploid 'Anna',
Diploid 'Rendezvous',
Triploid 'Cotton Candy',
Triploid 'El Camino',
Tetraploid 'Lem's Monarch',
Tetraploid 'Marinus Koster',
Tetraploid 'Point Defiance',
Suspected Polyploid 'Arnold Piper'

Source: Whitney Nursery

John and Sally Perkins

[(cumberlandense X viscosum) X colemanii] is a Triploid

Two seedlings of [(Rhododendron cumberlandense X R. viscosum) X R. colemanii], 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. Rhododendron colemanii is a tetraploid species.

In this 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 R. viscosum) X R. colemanii],
Tetraploid Rhododendron colemanii

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

Rhododendron Website You Should Use

Everyone who loves rhododendrons, and especially those contemplating purchases (e.g. Van Veen orders) should be aware of the following website:

 

http://www.hirsutum.info/

 

Its stated purpose:  "The purpose of this website is to give an overview (photos and information) of as many rhododendron species and cultivars (hybrids) as possible. A virtual botanical garden. A virtual arboretum.  An online database with information and pictures."

 

It currently has over 1200 species and over 16,000 hybrids, most with multiple photos.  It continues to grow with the expectation that eventually it will contain all registered (and many unregistered) hybrids that are still in existance.  It has very flexible search capabilities.

 

I recommend you explore this most useful site - and even contribute info to the authors, if possible.

 

Joe Bruso

'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

Introducing Miss Polly Ploidy

Miss Polly Ploidy answering a question concerning Rhododendron 'Hurricane'.

'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

Reminder: Founder's Day Brunch @ Sun Nov 14 11:30am - 4pm (ARS Massachusetts Chapter Calendar)

more details » Founder's Day Brunch Dick Jaynes Talk Brunch, Seed Exchange When Sun Nov 14 11:30am – 4pm Eastern Time Where Papa Razzi, Wellesley, MA (map) Calendar ARS Massachusetts Chapter Calendar Who • John Perkins - creator

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'August Lamken' is a Triploid

Rhododendron 'August Lamken', which is a Dietrich Hobbie hybrid documented as 'Doctor V.H. Rutgers' x R. williamsianum, 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.

'August Lamken' is hardy in zone 6.

Summary of Ploidy Levels

Triploid 'August Lamken'

Source: John and Sally Perkins

John and Sally Perkins

'Beauty of Littleworth' is a Triploid

Rhododendron 'Beauty of Littleworth', which is a 1884 James Henry Mangles hybrid documented as R. griffithianum x R. campanulatum ssp. campanulatum, 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.

Summary of Triploids from the 19th century

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

Source: Whitney Nursery

John and Sally Perkins

'Diane' is a Diploid

Rhododendron 'Diane', which is a Koster hybrid documented as a 'Mrs. Lindsay Smith' hybrid, 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.

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

Summary of Ploidy Levels

Diploid 'Diane',
Diploid 'Mrs. Lindsay Smith',
Diploid 'Rothenburg',
Triploid 'Broughtonii',
Triploid 'Gomer Waterer',
Triploid 'Phyllis Korn',
Triploid 'Pink Pearl'

Source: Whitney Nursery

John and Sally Perkins

'Opal Thornton' is a Triploid

Rhododendron 'Opal Thornton', which is a John Thornton hybrid documented as 'Antoon van Welie' x R. hyperythrum, 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.

John Thornton's Breeding Rhododendrons for the Gulf South

Summary of Ploidy Levels

Triploid 'Opal Thornton',
Tetraploid 'Antoon van Welie'

Source: Rarefind Nursery

John and Sally Perkins

Reminder: Board Meeting @ Wed Nov 10 7:30pm - 9pm (ARS Massachusetts Chapter Calendar)

more details » Board Meeting When Wed Nov 10 7:30pm – 9pm Eastern Time Where Hardings (map) Calendar ARS Massachusetts Chapter Calendar Who • John Perkins - creator

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'Hank's Folly' is a Triploid

Rhododendron 'Hank's Folly', which is a Hank Schannen hybrid documented as 'Chionoides' x 'Gibraltar', 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.

'Hank's Folly' is a cross of an elepidote with a deciduous azalea.

'Gibraltar' has been determined to be a tetraploid using flow cytometry by Dr. Thomas Ranney, J.R. Jones, and Nathan Lynch.

Summary of Ploidy Levels

Triploid 'Hank's Folly',
Tetraploid 'Gibraltar'

Source: Rarefind Nursery

John and Sally Perkins

Reminder: Founder's Day Brunch @ Sun Nov 14 11:30am - 4pm (ARS Massachusetts Chapter Calendar)

more details » Founder's Day Brunch Dick Jaynes Talk Brunch, Seed Exchange When Sun Nov 14 11:30am – 4pm Eastern Time Where Papa Razzi, Wellesley, MA (map) Calendar ARS Massachusetts Chapter Calendar Who • John Perkins - creator

Invitation from Google Calendar You are receiving this email at the account john.a.perkins@gmail.com because you are subscribed for reminders on calendar ARS Massachusetts Chapter Calendar. To stop receiving these notifications, please log in to https://www.google.com/calendar/ and change your notification settings for this calendar.

'Betty Hume' is a Diploid

Rhododendron 'Betty Hume', which is a C.O. Dexter hybrid, 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.

The nursery literature often mentions the following as suspected polyploids:

'August Lamkin': suspected polyploid - tested triploid,
'Betty Hume': suspected tetraploid - tested diploid,
'Gargantua': suspected triploid - tested tetraploid,
'Hallelujah!': suspected tetraploid - tested triploid,
'Marie Hoffman': suspected tetraploid - tested diploid

Summary of Ploidy Levels

Diploid Betty Hume

Source: Werner Brack
Source: Don Hyatt

John and Sally Perkins

'Cynthia' is a Fertile Triploid

Rhododendron 'Cynthia', which is a 1856 Standish and Noble hybrid documented as R. catawbiense x R. griffithianum, 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.

'Cynthia' is the pollen parent of 'Countess of Derby'. M. Stockman used 'Cynthia' as a seed or pollen parent in several of his crosses.

'Countess of Derby', which has 'Pink Pearl' and 'Cynthia' as parents and 'Broughtonii' as an ancestor, is a cross between 2 fertile triploids.

Summary of Ploidy Levels

Triploid 'Broughtonii',
Triploid 'Cynthia',
Tetraploid 'Countess of Derby'

Source: Whitney Nursery

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

Reminder: Board Meeting @ Wed Nov 10 7:30pm - 9pm (ARS Massachusetts Chapter Calendar)

more details » Board Meeting When Wed Nov 10 7:30pm – 9pm Eastern Time Where Hardings (map) Calendar ARS Massachusetts Chapter Calendar Who • John Perkins - creator

Invitation from Google Calendar You are receiving this email at the account john.a.perkins@gmail.com because you are subscribed for reminders on calendar ARS Massachusetts Chapter Calendar. To stop receiving these notifications, please log in to https://www.google.com/calendar/ and change your notification settings for this calendar.

'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

'Colonel Coen' is a Diploid

Rhododendron 'Colonel Coen', which is a Ostbo hybrid, 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 'Colonel Coen'

Source: Bob Fox

John and Sally Perkins