Tokyo

Chinese plant scientists are hoping that a proposed new satellite will deliver not only agricultural breakthroughs but also a greater understanding of how to make plants mutate.

The satellite project, which was announced late last month, is designed to expose plant seeds to cosmic radiation, zero gravity and other effects that are encountered only in space.

It aims to “make breakthrough mutations with important economic significance, such as crop yield and quality”, according to Liu Luxiang, director of the Space Breeding Centre at the Chinese Academy of Agricultural Sciences, which is promoting the project.

Chinese scientists say they have already discovered several rare, inheritable genetic mutations — capable, they say, of producing giant sweet peppers as well as improving the quality of rice and wheat — using recoverable satellites and high-altitude balloons.

The new project aims not only to identify more mutants, but also to establish their causes. “It could take advantage of the many kinds of radiation, such as gamma rays, X-rays and secondary emissions, at many energy levels, that can affect plants and seeds,” says Didier Schmitt of the European Space Research and Technology Centre (ESTEC), a European Space Agency laboratory in Noordwijk, the Netherlands, which is not involved in the project.

The satellite will be designed with minimum protection against radiation — in contrast to the heavily protected research facilities sent into space by Russia and the United States. Radiation detectors and special compartments — such as one protected against radiation and another containing a gravity simulator — will help researchers to identify the role of these factors in causing mutations.

The fact that cosmic radiation causes mutations is well known, but the effect of microgravity remains disputed. Some researchers think that the combination of the two could produce some interesting results. “There might very well be a synergy effect of radiation and lack of gravity,” says Enno Brinckmann, ESTEC's senior biologist.

Seeds will be loaded onto the satellite, which will then be launched into orbit. When the satellite is recovered, the seeds will be grown and screened for mutants in a process that will take three to five years.

The plan, which could cost as much as RMB200 million (US$25 million) for the satellite alone, has yet to be approved by the Chinese government, but Liu says he is optimistic that it will go ahead.

The project “would be unique as an unattended facility specifically for plant mutation studies,” says Brinckmann. Schmitt agrees that it would complement other satellite-based biological research as well as experiments planned for the International Space Station.