Space mutants?

Science World, March 7, 2003 by Mona Chiang

What's blooming from China's budding space program? Bigger flowers and supersize veggies: For more than a decade, the Asian nation has made use of Earth's upper atmosphere (thick layer of surrounding gas)--up to 402 kilometers (250 miles) high--for seed-breeding research. A variety of seeds, including corn and water-melon, have traveled in space for up to two weeks in recoverable satellites and high-altitude balloons.

How did space affect the seeds? Evidently, the high radiation (strong invisible energy waves) of space mutated, or genetically modified, the seeds' DNA--hereditary material stored in their cells, reports China's Xinhua News Agency.

These mutations may explain why peony flowers grown from "space seeds" are larger and more colorful than normal; the mutations may also explain jumbo, half-pound bell peppers and a new breed of fast-growing rice.

Not all space-mutant seeds sprout big results, though. In many experiments on Earth, radiation caused negative changes in exposed seeds. "Radiation induces mutations on a cell-by-cell basis," says plant physiologist Daniel Barta of NASA Johnson Space Center in Houston, Texas. "It won't affect all plant cells in the same way." Radiation creates a wide and random variety of changes that scientists can't control. In other words, zapping seeds isn't a sure-fire way to sprout gorgeous flowers or mammoth veggies.

But space mutants may be a start. Because many mutated plants don't pass on their traits to offspring, developing a plant that yields seeds with a specific mutation could take years of selective breeding. Scientists would need to test every space seed by growing it into a plant. Then plants that display hints of the desired trait would be cultivated until, finally, plants that consistently display the trait result.

It's uncertain how the Chinese produced their jumbo space produce, but the hefty half-pound Space Tomato No. 1 reportedly took more than seven years to cultivate!