Australia joined the 'space breeding' club in September, sending wheat and barley seeds into space on a Chinese Long March rocket in the hopes that the unique environment in space would encourage beneficial mutations.

Credit: AFP

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PERTH: Plant seeds have been blasted into orbit in the hope that 'space breeding' holds the key to improving crop yields and disease resistance.

Wheat and barley strains developed by the Department of Agriculture and Food in Western Australia (WA) have just landed back on Earth following a 15-day orbital cruise on board China's Shijian-8 satellite.

"Space-breeding refers to the technique of sending seeds into space in a recoverable spacecraft or a high-altitude balloon," said Agriculture WA barley breeder Chengdao Li. "In the high-vacuum, micro-gravity and strong-radiation space environment, seeds may undergo mutation."

The satellite also carried aloft 2,000 seeds from nine varieties of vegetables, fruits, cotton and fungi.

Agriculture WA sent up two of its best grain varieties, the wheat grain 'wyalkatchem' and the barley grain 'vlamingh', as part of a crop breeding program designed to improve grain varieties back on Earth.

Some of the space seeds, germinated in WA before entering the microgravity conditions above the planet, have now been planted at a summer nursery in southern WA.

They will be harvested next season to determine if they show improved yield, disease resistance or nutritional value.

"The seeds will be in trials for several years in WA to select better varieties for high yield, better quality and tolerance to drought and frost," said Li, adding that Earth-bound strains of vlamingh and wyalkatchem will be used as controls.

Li said microgravity interfered with cell division and development by increasing plant sensitivity to radiation and interfering with DNA repair. Cosmic rays, which include electrons, protons and low and high energy heavy ions, also can cause cell plasma and DNA damage. Cosmic radiation significantly increased mutation rates in the seeds.

On Earth, life is protected from this radiation by the atmosphere.

WA Agriculture and Food Minister Kim Chance said in a statement last month that space breeding was a new science, combining astronautics, genetics, radiation and plant breeding: "Space breeding subjects the seed to cosmic radiation and microgravity, which can cause natural changes in the seed. It is an extension of traditional mutation breeding techniques already carried out as part of … breeding programs and it does not involve any [artificial] genetic modification of the seed."

Li said the research promised new varieties of important grains whose future was under threat by climate change, disease and drought. Ultimately, the aim was to establish a simulated space-breeding centre on the Earth based on the data collected from this satellite flight, he said.

The space breeding experiment is a collaboration between the Chinese National Space Breeding Centre, the Academy of Agricultural Sciences and the U.N.'s International Atomic Energy Agency.

U.S., Russian and Chinese space agencies have been sending up seeds and seedlings since the early 1960s in the hope of growing new plants free of the impacts of disease and drought, and gravity.

The two grain varieties were bred in Perth, WA by the department with the Australian Grains Research and Development Corporation.