As a boy in Chicago, Robert J. Griesbach eyed the flowers his geneticist father was cross-breeding and asked himself, why ARE roses red and violets blue?
As a plant geneticist, Griesbach has spent 15 years at the Agricultural Research Service in Beltsville trying to answer that question.
Now, the Ellicott City man thinks he has the answer, one that vaults genetic research over a decades-old barrier and that could open up a new world of striking, first-of-their-kind flower colors -- blue roses, red Easter lilies, pumpkin-colored petunias.
His three years of research tracked 600 genetically engineered petunias and created a chart that links their colors to their genes.
"Right now, we could probably create any color we want in any plant we want," he said.
By creating markets for flowers with genetically crafted shades, his work also could be a boon for the $1.3 billion gardening and ornamental plant industry.
"Ornamentals are a multi-billion-dollar industry in this country, and the whole reason is the color," said Griesbach of a national obsession that draws suburbanites to nurseries each weekend and puts seed catalogs and fliers in their mailboxes.
In recent months, Griesbach has been taking his findings on the road, explaining them to groups like the American Rhododendron Society in Roanoke, Va., and the American Orchid Society in West Palm Beach, Fla., and writing about them in trade journals.
"At this point, what we have to do is get the word out," he said.
Gardeners have cross-bred flowers for centuries, mixing red violets with blue ones, for example, to yield purple.
But Griesbach said researchers hit a dead end in the 1960s when their efforts yielded a variety of colors they could not explain, such as the shades that resulted from cross-breeding varieties of purple flowers.
Breakthroughs in genetic research in the 1980s turned up evidence that flower colors were determined by their acid levels.
Now, Griesbach's research has confirmed what had been theorized for a decade: that the flower's pH, or acid level, is what determines the space between the molecules and ultimately the color of the flower itself.
Griesbach, 42, who holds a doctorate in genetics from Michigan State University, said he chose petunias for his research, rather than any other type of flower, because they flower in a month, are major sellers and their biochemistry is well documented.
He said to go beyond petunias, plant breeders still have to research the biochemistry of individual flowers to come up with genetically engineered varieties.
But plant breeders say Griesbach's research has implications for anyone who puts a spade into the earth, from the backyard gardener to the professional landscaper.
"There's always a need for more variety, for more color," said Carl Scharfenberg, a vice president and plant breeder at Yoder Brothers nursery in Fort Myers, Fla., the world's largest breeder of chrysanthemums.
"Our need is for a real red; our reds are dull," Scharfenberg said.
He said with Griesbach's work red chrysanthemums may be about three to five years away, rather than 25 years.
Griesbach said breeders would have to ask themselves whether it will be cost-effective to fund the biochemical research necessary to create a red chrysanthemum or a blue rose.
Scharfenberg said that would happen -- eventually.
"Flower prices haven't increased in many years and the direction is toward maximizing the greenhouse space and the soils that you have. With more variety, you'll be able to appeal to more people," Scharfenberg said.
Griesbach's enthusiasm for his mission is apparent as he bounds from a chair in his office to a Tinker Toy-like model of a petunia suspended from his ceiling to describe the flower's cell structure.
Some of his explanation is lost on a visitor. But he agrees that it comes down to this: Red flowers are highly acidic and have molecules that are far apart. Blue flowers have molecules that are closer together and less acidic.
"It was all theory in the 1980s, but it's been proven in the 1990s," he says, using a pencil to point at the model.
A scientist to the core, he spends weekends searching for fossils and prehistoric amber specimens with his two children at construction sites and waterfronts.
He also is always on the lookout for unusual plant varieties -- mutants -- at area nurseries.
On a recent trip to a Beltsville nursery, he spotted some brightly colored African violets and let out a response that apparently embarrassed his wife.
"I picked them up and I said, 'Hey, look at these regulatory mutants.' And she said, 'Don't say that too loud. People will think you're strange.' "
Pub Date: 7/23/96