Mutation breeding raises concerns
Crops changed by radiation not being regulated for safety
HOUSTON Crop breeders increasingly are using radiation and gene-altering chemicals to mutate seeds, creating new plant varieties with better yields — all without regulation.
The United Nations’ Nuclear Techniques in Food and Agriculture program has received 39 requests this year for radiation services from plant breeders in dozens of countries, the most since records began in 1977, according to program head Pierre Lagoda. The group in Vienna promotes developing more “sustainable” crops by irradiating them to resist threats like drought, insects, disease and salinity.
Mutation breeding, after booming in the 1950s with the dawn of the Nuclear Age, is still used by seed developers from BASF SE to Dupont Co. to create crops for markets that reject genetic engineering. Regulators don’t demand proof that new varieties are harmless. The U.S. National Academies of Science warned in 1989 and again in 2004 that regulating genetically modified crops while giving a pass to products of mutation breeding isn’t scientifically justified.
“The NAS hits the nail on the head and I don’t think that any plant- or crop-scientist will disagree,” said Kevin M. Folta, a molecular geneticist in the horticultural sciences department at the University of Florida. “Mutation breeding is absolutely the least predictable.”
The increase in mutation breeding raises questions of fairness and safety compared with genetic engineering, a regulated technique used by companies such as Monsanto Co. that involves transferring specific genes from one species to another. Monsanto’s Roundup Ready soybean, a blockbuster product in the U.S. and Brazil, can’t be grown in the European Union, where national governments have cited concerns about risks to health and the environment.
In contrast, mutagenesis deletes and rearranges hundreds or thousands of genes randomly. It uses a manmade process that mimics with a greater intensity what the sun’s radiation has done to plants and animals for millennia, spawning mutations that can be beneficial or hazardous to the organism.
The randomness makes mutagenesis less precise than St. Louis-based Monsanto’s genetically modified organisms, known as GMOs, the NAS said in a 2004 report. It’s the breeding technique most likely to cause unintended genetic changes, some of which could harm human health, the academy said.
Still, mutagenesis is gaining in popularity because it’s a far cheaper way to give crops new traits than the $150 million to $200 million that companies such as Monsanto pay to get a new GMO on the market. Mutant crops also face no labelling requirements or regulatory hurdles in most of the world.
“These difficulties in getting a GMO to the market, we don’t have it in mutation breeding,” Lagoda said in an Oct. 16 phone interview.
Breeders have registered more than 3,000 mutant varieties with Lagoda’s program, a partnership between the UN’s Food and Agriculture Organization and the International Atomic Energy Agency. Those varieties are just “the tip of the iceberg” because many breeders actively avoid revealing how they create new plants, Lagoda said.
This year alone, Lagoda’s program has received requests to help irradiate 31 plant species, ranging from sugar beets from Poland and wheat from the U.K. to rice from Indonesia and potatoes from Kenya.
Some of the program’s greatest successes have been in Asia. Lower labour costs there make it practical to sort through tens of thousands of plants to find a variety with the desired change. In Vietnam, mutant varieties of soy account for half of the crop and higher yields from mutant rice has made the country self-sufficient in that grain, Lagoda said. Vietnam is using the technique to develop salttolerant rice, he said.
Mutant breeding was developed during the Second World War and promoted during the Cold War as a peaceful use of nuclear technology. It created thousands of new plant varieties by knocking out genes with Xrays and gamma rays as well as chemicals.
Atomic gardens, built around gamma-ray emitters, were popular among breeders in the 1960s and Japan still operates one. China began launching seeds into space in 1987 to take advantage of cosmic radiation and low gravity, developing more than 40 mutant crops with higher yields and better disease resistance, including varieties of rice, wheat and pepper.
Most of the world’s wheat, rice and barley are descendants of mutant varieties, according to Lagoda. Mutagenesis is used to give fruits and vegetables a new colour and to make grains shorter and easier to harvest. In the U.S., mutagenesis was used to develop Star Ruby grapefruit and varieties of lettuce, beans, oats, rice and wheat.
BASF, the world’s biggest chemical company, is having success with its line of Clearfield crops. The German company made the crops tolerant of its Clearfield herbicide through chemical mutagenesis. It alters the crops’ DNA by dousing seeds with chemicals such as ethyl meth-anesulfonate and sodium azide, according to filings in Canada, the only nation that regulates such crops.
“This has been a technique used for many decades without issue, without concern,” Jonathan Bryant, a BASF vicepresident said by phone.
BASF enlists the help of 40 seed companies, including DuPont Co. and Dow Chemical Co. in the U.S. and Switzerland’s Syngenta AG to sell Clearfield crops in markets that reject GMOs. Clearfield wheat, rice, lentils, sunflowers and canola are planted from Russia to Argentina and the U.S. without regulatory review.
Operating earnings at BASF’s agriculture unit rose 27 per cent last year, partly because of higher demand in Eastern Europe for Clearfield herbicide and the mutant crops that tolerate it, the company said in its annual report.