The recent July 4th email newsletter sent out by Schreiner's had a link to a NY Times science article which talks about the late Rick Ernst's work with Oregon State Univ on red iris genetics. Very interesting reading. I think from June 2006 titled The Hunt Continues for the Holy Grail:a Red iris.
Irises are among the easiest flowers to propagate, and growers everywhere have sought to put their own spin on them, offering an array of elaborate blooms in virtually every color of the rainbow. Except one: red.
Sure, there are irises billed as red, but they veer toward shades of wine, brick or reddish brown.
What started as an informal race among growers to create a truly red iris has developed into a decades-long marathon. It persists despite advancements in science, and efforts to modify the flower genetically by Richard Ernst of Cooley's Gardens outside Salem, Ore., in conjunction with researchers at Oregon State University.
In 2004, Mr. Ernst — a well-known hybridizer who for decades pursued the red iris the old-fashioned way, crossing varieties with characteristics deemed logical to produce a red — predicted that the genetic retooling efforts would be successful in time to show off a red iris at the national conference of the American Iris Society in May.
But it appears it will be at least another two years before the results are known.
"We expected to spend only four years; we're now on 14 years," Mr. Ernst said. "After about eight years we were getting a little bit disgusted. It was taking too long. Then we came to the realization of how complicated this is."
Just as efforts to create a blue rose have stymied growers and plant geneticists, so have efforts to create a red iris. The flower has almost no red pigment naturally.
Tony H. H. Chen, a professor at Oregon State who is heading the project for Mr. Ernst, is working to introduce genes from two different lilies — the coral lily (Lilium pumilum) and the tiger lily (Lilium lancifolium, formerly Lilium tigrinum) — and an ordinary red pepper to put more red in the flower. But before that could be attempted, Dr. Chen had much to do.
"We knew little about the iris at the molecular level," Dr. Chen said. "Not many people like to work on a minor crop such as iris."
It took three years to establish a protocol for regeneration of the plant from cultured cells. Then it took an additional two to three years to develop a way to insert a marker gene, and longer still to grow a transgenic plant with that gene.
Mr. Ernst, who estimates that he will have spent at least $1 million by the time the process is complete, says his aim is to create a tall bearded iris with a 38-inch stem, 10 buds and a flower 6 to 6½ inches across, with all parts the same color.
"Hopefully, we'll be successful," he said. "If not, perhaps we'll get a deeper shade of pink, and maybe we'd be able to hybridize it within its own gene pool to bring out the red even more."
Dr. Chen is following two tracks. One involves introducing a gene from bacteria that would increase the material on which lycopene, a pigment that gives tomatoes their red color, builds during biosynthesis. While some irises, typically those that are pinkish or yellowish, contain small amounts of lycopene or carotene, an orange-red pigment common to carrots, it appears that they break down during the process.
Another issue is that virtually every iris contains anthocyanin, a pigment responsible for the purple colors so prevalent in the flower. Mr. Ernst said it could be found in every so-called red iris being marketed, including his own Classic Bordeaux, which appropriately is more wine-colored than red.
Keith Keppel, a hybridizer in Oregon, said the irises currently categorized as red were essentially tricking the eye. Two classes of pigments contained in the plant's cells — oil-soluble ones like xanthophylls and carotenes that result in yellows, pinks and oranges in the flower and water-soluble anthocyanin — mingle in the epidermal layer, creating a reddish color to the eye.
"If you can get the right combination, you can get what you could apologetically say is a red iris," Mr. Keppel said. "Still, it's not."
While hybridizers have successfully crossed plants to achieve a poppy-red beard on the flower, they have not found a way to bring the color out on the petals, known as standards and falls.
Don Spoon of Winterberry Gardens in Cross Junction, Va., who has spent more than 20 years pursuing the red iris, still hopes to achieve a true red through cross-breeding. Mr. Spoon is crossing irises on themselves, with siblings and cousins, and outside the line with the hope of introducing recessive modifier genes that will intensify the lycopene throughout the flower. But even if he is successful, he said, he needs to tone down the orange-red of the lycopene pigment. To do that he is trying to bring out lavender-blue influences in the anthocyanin pigment.
"Even if you get an iris with lycopene in the petals and falls, it will not be signal red, it will be orange-red, so you have to cool it with a specific type of anthocyanin," he said.
Mr. Spoon said he made 1,500 crosses of plants last year, and about a third of those were dedicated to the pursuit of the red iris.
Dave Schreiner, president of Schreiner's Iris Gardens just down the road from Cooley's, said he also thought it was possible to create a red iris through hybridization, although he acknowledged that "hybridizing is basically like playing with nature's dice."
"All sorts of variations come up," he said.
And so they have. Among the tall bearded iris, hybridizers have achieved a range of varieties, including bicolors, plicatas (flowers with stippled, dotted or stitched margins), repeat bloomers and stems with average bud counts of seven or eight.
"Who knows who or even if we can discover the holy grail?" Mr. Schreiner said. "That is the fun part of working with nature."
