Amphidiploid Arilbreds
Early
arilbred breeding, which focused on crossing diploid oncocycli with
diploid or tetraploid tall beardeds, was greatly hampered by the
sterility of most of the progeny, not to mention difficulties in
making the crosses and germinating the seeds. Except for an
occasional break, such as 'Ib-Mac' or 'Capitola', in which a fertile
amphidiploid was produced fortuitously, there was little opportunity
to breed the arilbreds for desired qualities.
This situation eventually changed when C. G. White produced a family of fertile amphidiploid arilbreds, with two sets of aril chromosomes and two sets of tall bearded chromosomes. He did not keep breeding records, so we cannot be certain how this was accomplished. When an enormous number of seedlings are raised, some amphidiploids will be produced from unreduced gametes or other chromosome anomalies. Most modern arilbreds are descended from the C. G. White amphidiploids. Most "halfbreds" are members of this fertile family, while those less or more than half aril are typically infertile or of limited fertility.
This family can be expanded by crossing the tetraploid arils with the 48-chromosome bearded irises. This is important for expanding the genetic base of both the aril and the bearded component. The arils used in White's breeding were advanced generation oncogelias and oncocyclus hybrids, which he renewed annually from seed. Some species were doubtless more strongly represented in this mix than others. The "onco look" will always be a desirable trait in arilbreds, but recent fertile arilbreds from Regelia breeding are also interesting and desirable plants. On the bearded side, C. G. White's arilbreds stem from early 20th-century TBs. Using modern TBs and BBs should produce improved arilbreds, contributing modern form, substance, and branching to the mix. If the 48-chromosome dwarfs and medians are used, fully fertile arilbred medians result. Harald Mathes's 'Anacrusis' and its descendents are examples of such breeding.
I plan to focus my work with this family on fertile arilbred medians, including regeliabreds.
2018 saw maiden bloom on the first batches of seedlings from this work, crosses of 'Night Mood' x 'Werckmeister's Beauty' and 'Sultry Dreams' x 'Werckmeister's Beauty'. Saddly, however, the crosses seem to have been contaminated, with no aril characteristics evident in the seedlings. One from 'Sultry Dreams' x 'Werckmeister's Beauty' bloomed for the first time in 2019, and its veining and flower form encouraged me to think that it may truly be a child of 'Werckmeister's Beauty'. I'm not at all certain of that, but I am keeping it and using it as though it were the genuine article. In 2017, encouraged by the apparent tetraploidy of an Iris reichenbachii form from Mt. Vikos, Greece, I obtained many pods from its pollen on 'Dunshanbe'. Not all seeds appeared viable, but the total yield was still quite copious. No seedlings yet, alas.
Bearded Species for Breeding Arilbred Medians
Arilbred Irises: A Little History (AIS blog)
The Legacy of 'Anacrusis' (AIS blog)
Ib-Mac (C. G. Van Tubergen, BRS). AB/OB , MB. Medium red bitoned blend. I. iberica x I. macrantha. Van Tubergen, 1910. [44 chr.]
The first known amphidiploid arilbred, resulting from an unreduced gamete from I. iberica.
Capitola (Frank Reinelt, R. 1940). AB/OB, IMB, medium height, E. Dark red violet. 'William Mohr' x 'Ib-Mac'. 1940. [43 chr.]
'Ib-Mac's pollen-fertile offspring, once again thanks to an unreduced gamete from the pod parent. 'Capitola' was widely used in breeding, although mostly with TBs to produce the quarterbred "Mohrs", there being few other fertile arilbreds at the time to cross it with.
Kalifa Gulnare (Clarence G. White, R. 1954). Sdlg. 23B54. AB/OGB , EC, 34” (86 cm), E. S. pale orchid lavender; F. same, heavily overlaid apricot buff. Parentage unknown. Craig, 1955. [44 chr.]
Of the many important fertile amphidiploid arilbreds produced by C. G. White in the 1950s, I selected 'Kalifa Gulnare' for this list because of its almost ubiquitous presence in the pedigree of the modern arilbreds, and its relative longevity as a popular garden iris through the decades.
Welcome Reward (Eugene Sundt by Lois Rich, R. 1971). Sdlg. S59119. AB/OB , 27" (69 cm), L. S. lilac veined deeper, bronze flush part way up rib; F. gold bronze, haft veined mahogany on gold, pinkish flush on lower half; dark brown signal; golden brown beard; gold style crests. Austin W142-O (onco interspecies) x 'Pink Formal'. Aril Society, 1971. [44chr]
While almost all fertile amphidiploid arilbreds in recent decades derive from the C. G. White varieties, 'Welcome Reward' is an exception: an amphidiploid oncobred of known parentage, resulting from an unreduced gamete from its oncocyclus pod parent. It has produced many important descendants.
Genetic Artist (Henry Danielson, R. 1971). Sdlg. F-66-1. AB/RB , 30” (76 cm), EM. Odd combination of bronzy yellow and blue; center of petals to sides of ribs metallic lavender blue; edges strongly colored red bronze with tints of henna; beard lavender. 'Frost and Flame' x 'Vulcanus'. Mount Clare Iris Gardens, 1972.
An alter ego to 'Welcome Reward', if you will, is 'Genetic Artist', an amphidiploid regeliabred with many interesting descendants. While it is easy to focus on oncocyclus qualities as the object of arilbred breeding, this spendidly colored iris reminds us that the Regelias also have unique colors, patterns, and forms to contribute to the mix.
Anacrusis (Harald Mathes, R. 1992). Sdlg. 88-MDB16. AB/OGB/ABM, 20” (51 cm), E. Oxblood red; red black signal and beards. 'Dresden Gold' x T-IAM: ((I. iberica x I. auranitica) x I. suaveolens (mellita)). Aril Society, 1992.
The pollen parent is a colchicine-induced tetraploid whose bearded ancestry comes entirely from the miniature dwarf species I. suaveolens. This represents the first significant incorporation into the fertile arilbred family of bearded iris genes that are not from the garden TBs. 'Anacrusis' and its descendants are indeed of median height, and there is great potential here for launching a family of fertile arilbred medians. Its descendant 'Concerto Grosso' won the C. G. White Medal in 2005.
'Anacrusis'
(Tasco, 2013)
(Mathes, 1992)
(Mathes, 2001)
(Rich by Whitely, 1992)
(McAllister, 2009)
(Tasco, 2012)
(Tasco, 2006)
(Tasco, 2011)
(Tasco, 2010)
(Tasco, 2014)
(Tasco, 2008)
(H. Danielson, 1972)
'Sultry Dreams' X 'Werckmeister's Beauty'
The list below shows the name of each plant I currently grow for breeding purposes, the source, and the year acquired.
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2018 |
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2018 |
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2011 |
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2017 |
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Glow of Love |
2019 |
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Malevil Iris Gardens |
2011 |
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2012 |
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Kentucky Arabian |
2019 |
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Malevil Iris Gardens |
2010 |
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2017 |
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Othmani |
2018 |
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Peresh |
2019 |
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2018 |
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2012 |
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2014 |
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2014 |
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2012 |
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Vivid Dream |
2019 |
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Sultry Dreams X Werckmeister's Beauty |
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B025-01 |
I. aphylla Werckmeister X Ballalaika Music |
from George Hildenbrandt seed |
Illustration: 'Concerto Grosso' (Mathes '98): an amphidiploid arilbred from Mathes's 'Anacrusis' line.
September 2010
updated October 2019
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Unless otherwise noted, all text and illustrations copyright Tom Waters and all photographs copyright Tom or Karen Waters. Please do not reproduce without permission.
