From red grapefruit to Asian pears, what radiation means to plant scientists and eaters around the world.
In 2006, Western Australia's Department of Agriculture and Food sent 215 kg of seeds—wheat, barley, and other vegetable seeds—on a 15-day spin around the world on board a Chinese Shijian-8 satellite.
Why send seeds into space? So that they come in contact with cosmic radiation, and so that radiation causes mutations and, potentially, new plant varieties.
Today, China has taken the lead—and an immense, nationalist pride—in radiation breeding, a technique commercially pioneered by Lewis J. Stadler, who bombarded barley and corn seeds with x-ray in the 1940s, to cause an increase in beneficial plant mutations. Research in the United States culminated in the following decades, flourishing in Gamma Gardens, at garden shows (above), and even making an appearance in 1961 in ad pages of Popular Science. "Absolutely safe—completely unpredictable," the ad boasted.
Paige Johnson, a garden scholar and nanotechnology researcher by day, writes on her blog Garden History Girl:
Atomic Gardens grew out of post-WWII efforts to use the colossal energy of the atom for peaceful pursuits in medicine, biology, and agriculture. “Gamma Gardens” at national laboratories in the US as well as continental Europe and the USSR bombarded plants with radiation in hopes of producing mutated varieties of larger peanuts, disease resistant wheat, more sugary sugar maples, and African violets with three heads and a singular atomic entrepreneur named C.J. Speas irradiated seeds on his Tennessee farm and sold them to schoolchildren and housewives.\n
Research institutes around the world continue to modify crops with gamma radiation, creating everything from drought-resistant rice to disease-resistant bananas. One of the centers is about 100 miles from Fukushima. The Institute of Radiation Breeding has a 88.8 Terabecquerel Cobalt-60 source, ringed by a 3,608-foot radius Gamma field (the world's largest), and a 28-foot high shield dike around the perimeter.
Here, Japanese scientists have bred disease-resistant nashi pears, including "Osa Gold" pictured below. Although the luster of radiation breeding appears to be waning with the advent of newer biotechnologies, one researcher wrote in 2008 (PDF) that “mutation breeding is still a very interesting and useful technology.”
Remarkably, the technique leaves no residual radiation in either the seeds or the crops and, unlike genetic engineering, does not introduce foreign genetic material into plants. Still, it creates arbitrary mutations. It's random and, in theory, those new proteins could present health and environmental risks.
Perhaps, more remarkable still is how the offspring of two grapefruit varieties created through radiation breeding —"Star Ruby" and "Rio Red"—have become the predominant variety grown in Texas, according a report by William J. Broad in The New York Times. (Unlike transgenic "genetically modified foods," which the Food and Drug Administration inventories here, there doesn't appear to be an authoritative list of the mutagenic varietals we eat.) These grapefruit, very much the product of radiation, can then be grown into fruits carrying the USDA Organic label, despite the stigma of "unnatural" that accompanies modern transgenic breeding or irradiation.
In Hybrid: The History and Science of Plant Breeding, Noël Kingsbury speculates that the lack of opposition around this issue may have to do with the technology's funding:
[I]t has always remained in the public sector; the institutions undertaking it are all publicly funded, results are published, and all the work done is clearly for the public good. There are no corporate-owned gamma fields, producing new crops to mesh with company-produced agrochemicals, no private secrets, no shareholders clamoring for higher dividends.\n
The distinction is important, demonstrating the complex feelings we have towards different biotechnologies that go into our food—all of which can come with unforeseeable risks.
You can search for the commercial registry of seeds here. For London readers, Paige Johnson will be presenting her research on the Atomic Gardening Society at the Garden Museum on June 7; register here.
Top photo via Frank Scherschel/Time & Life Pictures/Getty Images, via Life. Second photo via "Induced Mutations in Plant Breeding and Biological Researches in Japan" (PDF). Patent photo via Kazuo Kotobuki et al., 1998. Japanese pear tree names "Osa Gold." U.S. Classification Plt 178.