Monday, April 17, 2017

Iris Serendipity

By Bryce Williamson

Serendipity, meaning a fortunate happenstance or pleasant surprise, was coined by Horace Walpole in 1754. The notion of serendipity is a common occurrence throughout the history of scientific innovation such as Alexander Fleming's accidental discovery of penicillin in 1928, the invention of the microwave oven by Percy Spencer in 1945, and the invention of the Post-it note by Spencer Silver in 1968.
In the world of iris hybridizing, serendipity also plays an important role. In his recent blog, “Arilbred Irises: A Little History,”  Tom Waters wrote about “the iris 'William Mohr' that was essentially sterile….And occasionally 'William Mohr' would reward such persistence by producing a seed or two. We now understand that these seeds were the result of unreduced gametes, where an ovule is produced by bypassing the normal cell division.” From those beginnings, the Mohr class was born, a class of irises grow that with relative ease and have flowers with many aril characteristics. Today's Mohr types irises, as seen below, have come a long way in flower form and patterns.

Perry Dyer (Black '17)--Paul Black image

Confederate (Tasco '17-- Mohr type aril-median)
Photo by Rick Tasco

Unreduced gametes have also shaped other tall bearded irises of today. Snow Flurry is perhaps the most famous of those creations. Other hybridizers have followed this path.

Snow Flurry (Clara Rees)--photo by Rick Tasco

Writing on his Facebook page in 2016, noted iris authority Keith Keppel wrote that “in the 1930's, hybridizer Paul Cook crossed the greenish yellow diploid species Iris imbricata with a diploid ‘pallida pink’ seedling. A resultant seedling was then crossed to a tetraploid blue, and he obtained a seedling with standards somewhat darker than the falls.”
Then serendipity intervened and “He accomplished two things: (1) bringing imbricata genes into the tetraploid TB mix and (2) producing a blue with noticeably darker standards, the start of a reverse blue amoena. Interesting to note: he had begun the imbricata project hoping it would aid in the clarification of blue TB pigments; instead, he started a reverse amoena line."

Iris imbricata photo by Lloyd Baumunk

Mr. Keppel goes on to write, “A good hybridizer makes a cross for a purpose; a great hybridizer recognizes when something unexpected appears, goes off on a tangent, and develops something entirely different. Four generations from the initial imbricata cross, Cook introduced Wide World (1954) and the reverse amoena rush began.

Wide World (Cook)--photo by Milan Bla┼żek 

               “As time went on, depth of color and degree of contrast increased. Breeders began crossing these reverse amoenas with carotene pigment (oil soluble, warm colors) carriers and the reverse amoenas evolved into all manner of combinations of "reverse bicolors". Although many breeders were involved, it was George Shoop who made the most (and the most innovative) introductions of this new genre....his beloved 'dark tops.'"

Crowned Heads (Keppel)--photo by Jeanette Graham

Spring Tidings (Shoop) photo by Colleen Modra

Mood Ring (Keppel '17)--photo by Brad Collins

George Sutton Y-5-B image by Mike Sutton

These serendipity events may have value even today. In recent years, Mr. Keppel has been involved in what could be seen as an exercise in futility. He has been using “Iris albertii, a diploid species, (that) seems not to be in the general gene pool of modern tall beardeds.”

Iris albertii--photo by Keith Keppel

As he writes, “So.....why not....cross with tetraploids and see what happens? Easier said than done. Of many crosses made, only one....Smash X albertii....yielded seed: six seeds with two germinating and one lasting to bloom, 05-4A. If nothing else, the albertii shoulder patterning came through!

Smash (Craig)--photo by Vicki Craig

Keppel 05-4A--photo by Keith Keppel

Keppel 12-120A--photo by Keith Keppel

A good grower, 05-4A blooms prolifically, but is a problem in crossing. About every third cross produces a pod. About every third pod is not a false pregnancy, but would have 1 to 3 seeds. Further problem is, the seed doesn't germinate.” Then once again serendipity intervened when “one year three volunteer pods formed that had much larger seed than what I had been getting from the crosses made. Three pods...six seeds germinated. That one is 12-120A, taller (about two feet), considerably larger flower than its parent, making me think the unknown parent must be a tall bearded. And, it has limited fertility. Will it lead to anything different? Anything worthwhile? And if so, will I still be around to see it?
“The pleasures of iris hybridizing do not fall within the realm of instant gratification!”

Editor's Note: The image of Iris imbricata is designed to show what the species looks like, but it is doubtful that the clone shown is actually the iris used by Paul Cook in his hybridizing.

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