Developments to Watch
PLANT BREEDERS DISCOVER A STRAIGHT SHOT TO SUCCESS
Breeders of white orchids have to wait for three to six years, when a hybrid blooms, to see if it produces the desired albino petals. But U.S. Agriculture Dept. scientists have developed a method that allows them to get a sneak preview in just three days.
The secret? A "gun" that sprays white petals with microscopic gold pellets. The pellets are coated with a gene from corn plants that turns on pigment production. If the corn's regulator gene causes the orchid's white petals to turn color, breeders know that the orchid's own regulator must be broken--which is what they want. Left alone, an orchid with a broken regulator is sure to produce white offspring.
Breeding white orchids isn't such a big deal by itself. But Robert J. Griesbach, an Agriculture Dept. plant geneticist in Beltsville, Md., says the gene gun should be useful in all kinds of plant breeding. By shedding light on regulator genes, the process may even help scientists understand human cancers, which can be caused by regulator genes gone haywire, Griesbach says. Don't worry about using up a lot of gold, by the way: Each pellet is a tenth the size of the period at the end of this sentence.EDITED BY PETER COY